Pericardial Effusion

Introduction
Background

Pericardial effusion defines the presence of an abnormal amount and/or character of fluid in the pericardial space. It can be caused by a variety of local and systemic disorders, or it may be idiopathic. Pericardial effusions can be acute or chronic, and the time course of development has a great impact on the patient's symptoms. Treatment varies, and is directed at both removal of the pericardial fluid and alleviation of the underlying cause, which usually is determined by a combination of fluid analysis and correlation with comorbid illnesses.


Image is from a patient with malignant pericardial effusion. Note the "water-bottle" appearance of the cardiac silhouette in the anteroposterior (AP) chest film.


Pathophysiology

Embryology

In the human embryo, the pericardial cavity develops from the intraembryonic celom during the fourth week. The pericardial cavity initially communicates with the pleural and peritoneal cavities, but during normal development these are separated by the eighth week. Both the visceral and parietal pericardium are derived from the mesoderm, albeit from different parts of the embryo. The visceral pericardium develops from splanchnic mesoderm, as cells originating from the sinus venous spread out over the myocardium. The parietal pericardium derives from lateral mesoderm that covers and accompanies the developing pleuropericardial membrane, which will eventually separate the pleural and pericardial cavities. In healthy subjects, the pericardium covers the heart and great vessels, with the exception of only partially covering the left atrium.

Congenital absence of the pericardium can occur, and can be either partial or complete. It is often clinically silent, but can potentially lead to excessive cardiac motion (in the case of complete absence) causing vague chest pain or dyspnea, or, in case of partial absence with significant defects, strangulation of heart muscle and possible death.1

Physiology

The pericardial space normally contains 15-50 mL of fluid, which serves as lubrication for the visceral and parietal layers of the pericardium. This fluid is thought to originate from the visceral pericardium and is essentially an ultrafiltrate of plasma. Total protein levels are generally low; however, the concentration of albumin is increased in pericardial fluid owing to its low molecular weight.

The pericardium and pericardial fluid provide important contributions to cardiac function.
The parietal pericardium contributes to resting diastolic pressure, and is responsible for most of this pressure in the right atrium and ventricle.
Through their ability to evenly distribute force across the heart, the pericardial structures assist in ensuring uniform contraction of the myocardium.
The normal pericardium can stretch to accommodate a small amount of fluid without significant change in intrapericardial pressure. However, once this pericardial reserve volume is surpassed, the pressure-volume curve becomes steep. With slow increases in volume, pericardial compliance can increase to lessen the increase in intrapericardial pressure.

Clinical manifestations of pericardial effusion are highly dependent upon the rate of accumulation of fluid in the pericardial sac. Rapid accumulation of pericardial fluid may cause elevated intrapericardial pressures with as little as 80 mL of fluid, while slowly progressing effusions can grow to 2 L without symptoms.

Understanding the properties of the pericardium can help predict changes within the heart under physiologic stress:
During hypervolemic states, the pericardium limits acute cardiac cavitary dilatation.
By distributing forces across the heart, the pericardium plays a significant role in the physiologic concept of ventricular interdependence, whereby changes in pressure, volume, and function in one ventricle influence the function of the other.
The pericardium plays a pivotal role in cardiac changes during inspiration. As the right atrium and ventricle fill during normal inspiration, the pericardium, by limiting the ability of these chambers to dilate, contributes to the bowing of the atrial and ventricular septums to the left. This reduces LV filling volumes, which lead to the drop in cardiac output. As intrapericardial pressures rise, this effect becomes pronounced, eventually leading to the finding of pulsus paradoxus (discussed below), heralding the development of pericardial tamponade.

The cause of abnormal fluid production depends on the underlying etiology, but it is usually secondary to injury or insult to the pericardium (ie, pericarditis). Transudative fluids result from obstruction of fluid drainage, which occurs through lymphatic channels. Exudative fluids occur secondary to inflammatory, infectious, malignant, or autoimmune processes within the pericardium.
Frequency
United States
Few large studies have characterized the epidemiology of pericardial effusion; however, the available data consistently shows that they are more prevalent than clinically evident.
A higher incidence of pericardial effusion is associated with certain diseases.
Small pericardial effusions are often asymptomatic, and pericardial effusion has been found in 3.4% of subjects in general autopsy studies.
A wide variety of malignant neoplasms and hematologic malignancies can lead to pericardial effusion. Data on the prevalence varies, with some studies showing the presence of pericardial effusion as high as 21% in such patients. A large study by Bussani et al showed cardiac metastases (9.1%) and pericardial metastases (6.3%) in cases of death from all causes in individuals with an underlying carcinoma at autopsy.2 Malignancies with the highest prevalence of pericardial effusion include lung (37% of malignant effusions), breast (22%), and leukemia/lymphoma (17%).
Patients with HIV, with or without AIDS, are also found to have increased prevalence of pericardial effusion.3 Studies have shown the prevalence of pericardial effusion in these patients to range from 5-43%, depending on the inclusion criteria, with 13% having moderate-to-severe effusion. The incidence of pericardial effusion in patients infected with HIV has been estimated at 11%; however, whether highly active anti-retroviral therapy (HAART) has influenced this number is unknown.
Mortality/Morbidity

The mortality and morbidity of pericardial effusion is dependent upon etiology and comorbid conditions.
Idiopathic effusions are well tolerated in most patients. As many as 50% of patients with large, chronic effusions were asymptomatic during long-term follow-up.
Pericardial effusion is the primary or contributory cause of death in 86% of cancer patients with symptomatic effusions.
Survival rate for patients with HIV and symptomatic pericardial effusion is 36% at 6 months, 19% at 1 year.

Race
No consistent difference among races is reported in the literature.
AIDS patients with pericardial effusion are more likely to be white.
Sex
No sexual predilection exists.
Age
Observed in all age groups
Mean occurrence in fourth or fifth decades; earlier in patients with HIV3
Clinical
History

A patient with pericardial effusion may report the following symptoms:
Cardiovascular
Chest pain, pressure, discomfort: Characteristically, pericardial pain may be relieved by sitting up and leaning forward and is intensified by lying supine.
Light-headedness, syncope
Palpitations
Respiratory
Cough
Dyspnea
Hoarseness
Gastrointestinal
Hiccoughs
Neurologic
Anxiety
Confusion
Physical

Upon examination, a patient with pericardial effusion may have the following signs:

Cardiovascular
Classic Beck triad of pericardial tamponade (hypotension, muffled heart sounds, jugular venous distension).
Pulsus paradoxus: Exaggeration of physiologic respiratory variation in systemic blood pressure, defined as a decrease in systolic blood pressure of more than 10 mm Hg with inspiration, signaling falling cardiac output during inspiration.
Pericardial friction rub: The most important physical sign of acute pericarditis may have up to 3 components per cardiac cycle and is high-pitched, scratching, and grating. It can sometimes be elicited only when firm pressure with the diaphragm of the stethoscope is applied to the chest wall at the left lower sternal border. The pericardial friction rub is heard most frequently during expiration with the patient upright and leaning forward.
Tachycardia
Hepatojugular reflux: This can be observed by applying pressure to the periumbilical region. A rise in the jugular venous pressure (JVP) of greater than 3 cm H2 O for more than 30 seconds suggests elevated central venous pressure. Transient elevation in JVP may be normal.
Respiratory
Tachypnea
Decreased breath sounds (secondary to pleural effusions4 )
Ewart sign - Dullness to percussion beneath the angle of left scapula from compression of the left lung by pericardial fluid
Gastrointestinal - Hepatosplenomegaly
Extremities
Weakened peripheral pulses
Edema
Cyanosis
Causes

The following are causes of pericardial effusion.

Idiopathic: In most cases, the underlying cause is not identified.
Infectious
HIV infection can lead to pericardial effusion through several mechanisms, including the following:
Secondary bacterial infection
Opportunistic infection
Malignancy (Kaposi sarcoma, lymphoma)
"Capillary leak" syndrome, which is associated with effusions in other body cavities
Viral: The most common cause of infectious pericarditis and myocarditis is viral. Common etiologic organisms include coxsackievirus A and B, and hepatitis viruses.
Pyogenic (pneumococci, streptococci, staphylococci, Neisseria, Legionella species)
Tuberculous
Fungal (histoplasmosis, coccidioidomycosis, Candida)
Other infections (syphilitic, protozoal, parasitic)
Neoplasia
Neoplastic disease can involve the pericardium through the following mechanisms:
Direct extension from mediastinal structures or the cardiac chamber
Retrograde extension from the lymphatic system
Hematologic seeding
As mentioned previously, the most common cases of malignant effusion are lung, breast, lymphoma, and leukemia. However, patients with malignant melanoma or mesothelioma have a high prevalence of associated pericardial effusions.
Postoperative/postprocedural
Pericardial effusions are common after cardiac surgery. In 122 consecutive patients studied serially before and after cardiac surgery, effusions were present in 103 patients; most appeared by postoperative day 2, reached their maximum size by postoperative day 10, and usually resolved without sequelae within the first postoperative month. In a retrospective survey of more than 4,500 postoperative patients, only 48 were found to have moderate or large effusions by echocardiography; of those, 36 met diagnostic criteria for tamponade.5
Use of preoperative anticoagulants, valve surgery, and female sex were all associated with a higher prevalence of tamponade. Symptoms and physical findings of significant postoperative pericardial effusions are frequently nonspecific, and echocardiographic detection and echo-guided pericardiocentesis, when necessary, are safe and effective; prolonged catheter drainage reduces the recurrence rate.6
Pericardial effusions in cardiac transplant patients are associated with an increased prevalence of acute rejection.7
Other less common causes include the following:
Uremia
Myxedema
Severe pulmonary hypertension
Radiation therapy
Acute myocardial infarction, including the complication of free wall rupture
Aortic dissection, leading to hemorrhagic effusion in from leakage into pericardial sac
Trauma
Hyperlipidemia
Chylopericardium
Familial Mediterranean fever
Whipple disease
Hypersensitivity or autoimmune related
Systemic lupus erythematosus8
Rheumatoid arthritis
Ankylosing spondylitis
Rheumatic fever
Scleroderma
Wegener granulomatosis
Drug-associated (eg, procainamide, hydralazine, isoniazid, minoxidil, phenytoin, anticoagulants, methysergide)

http://emedicine.medscape.com/article/157325-overview

Atrial Septal Defect

Introduction
History of the Procedure

F. John Lewis successfully performed the first open heart closure of an atrial septal defect (ASD) on September 5, 1952, in Minneapolis, Minnesota. He used direct vision with hypothermia and inflow occlusion. Subsequent development of the cardiopulmonary bypass machine widely expanded the treatment of this and other congenital heart diseases more complex than ASD and spurred rapid expansion in the field of thoracic surgery.

In terms of establishing normal anatomy and eliminating sequelae, early repair of ASDs may well be the most successful application of open heart surgery of any congenital heart lesion. For nearly 50 years, surgical closure of ASDs has been almost exclusively accomplished with direct suture or patch repair on cardiopulmonary bypass. In recent years, use of a variety of transcatheter occlusion devices inserted through the defect in the septum has become common. For some patients, these devices have become an alternative to surgical procedures for the repair of the ostium secundum ASD. Surgical innovators have simultaneously developed minimally invasive techniques involving small incisions and even robotically assisted thoracoscopic approaches.
Problem

ASD is one of the most commonly recognized congenital cardiac anomalies in adults, but it is rarely diagnosed and even less commonly results in disability in infants. It is characterized by a defect in the interatrial septum that allows pulmonary venous return to pass from the left to the right atrium, resulting in right atrial and right ventricular chamber dilation, the extent of which depends on the size of the shunt. Patients, especially those with small or isolated defects, are usually asymptomatic through the first 3 decades of life, though more than 70% become impaired by the fifth decade. Early surgical closure of most types of ASD is recommended.
Frequency

ASD accounts for 10% of all congenital heart disease and for 22-40% of congenital heart disease in adults.

Ostium secundum defect is the most common type and accounts for 60-70% of all cases, for approximately 7% of all congenital cardiac defects and for 30-40% of all congenital heart disease in patients over age 40.

Ostium primum type accounts for 15-20% of all ASDs.

Sinus venosus type ASDs are seen in 5-15% of all patients.

Sex: ASD occurs with a female-to-male ratio of approximately 2:1.

Age: Patients with ASD are usually asymptomatic through infancy and childhood. Symptoms become more common with advancing age. By the age of 40 years, 90% of untreated patients have symptoms of exertional dyspnea, fatigue, palpitation, or sustained arrhythmia.
Etiology

ASD is a congenital cardiac disorder caused by the spontaneous malformation of the atrial septum.
Ostium secundum ASDs: incomplete adhesion between the original flap of the valve of the foramen ovale and the septum secundum after birth causes the probe-patent foramen ovale. The patent foramen ovale usually results from abnormal resorption of the septum primum during the formation of the foramen secundum. Resorption in abnormal locations causes a fenestrated or netlike septum primum. Excessive resorption of the septum primum results in a short septum primum that does not close the foramen ovale. An abnormally large foramen ovale can occur as a result of defective development of the septum secundum. The normal septum primum does not close this type of abnormal foramen ovale at birth. A combination of excessive resorption of the septum primum and a large foramen ovale produces a large ostium secundum ASD. About 10-20% of patients have associated mitral valve prolapse.
Ostium primum ASDs: These defects are caused by incomplete fusion of septum primum with endocardial cushion. The defect lies immediately adjacent to the atrioventricular (AV) valves, either of which may be deformed and incompetent. In most cases, only the anterior or septal leaflet of the mitral valve is displaced, and it is commonly cleft. The tricuspid valve is usually not involved. The defect is often large.
Sinus venosus ASDs: Abnormal fusion between the embryologic sinus venosus and the atrium causes these defects. In most cases, the defect lies superior, high in the atrial septum near the entry of superior vena cava, and it is associated with partial anomalous drainage of the right superior pulmonary vein. The relatively uncommon inferior type is associated with partial anomalous drainage of the right inferior pulmonary vein. Anomalous drainage can be into the right atrium, the superior vena cava, or the inferior vena cava.
Coronary sinus defect: Coronary sinus defect is characterized by unroofed coronary sinus and persistent left superior vena cava that drains into the left atrium. A dilated coronary sinus often suggests this defect. The diagnosis can be made by injecting contrast agent into left upper extremity; coronary sinus opacification precedes right atrial opacification.
Other ASDs
Certain ASDs may occur on a familial basis. Holt-Oram syndrome is characterized by an autosomal dominant pattern of inheritance, deformities of the upper limbs (most often, absent or hypoplastic radii), and ECG abnormalities, such as right bundle-branch block or first-degree AV block. A single gene defect with a penetrance of nearly 100% is the apparent cause of Holt-Oram syndrome. Approximately 40% of cases are due to new mutations; the rest are inherited from a parent.
Another example is the syndrome of familial ASD with prolonged AV conduction. This syndrome is an autosomal dominant trait with a high degree of penetrance but no associated skeletal abnormalities.
Both Holt-Oram syndrome and familial ASD with prolonged AV conduction affect nearly 50% of first-degree relatives of the patient.
Pathophysiology

The magnitude of the left-to-right shunt depends on defect size and relative compliance of the ventricles and the relative resistance in both pulmonary and systemic circulation. In patients with small ASDs, left atrial pressure may exceed right atrial pressure by several millimeters of mercury, whereas mean atrial pressures are nearly identical if the defect is large. Left-to-right shunting occurs predominantly in late ventricular systole and in early diastole, with some augmentation during atrial contraction. The shunt results in diastolic overload of the right ventricle and increased pulmonary blood flow.

Resistance in the pulmonary vascular is commonly normal or low in older infants or children with ASD, and the volume load is usually well tolerated though pulmonary blood flow may be 2-5 times more than systemic blood flow. A transient and small right-to-left shunt that occurs with the onset of left ventricular contraction, especially during respiratory periods of decreasing intrathoracic pressure, is common in patients with ostium secundum ASD, even in absence of pulmonary hypertension.

Pregnancy can increase shunt volume and lead to congestive heart failure (CHF). Pulmonary artery pressure usually remains normal and well tolerated.

A chronic left-to-right shunt fixes pulmonary hypertension and eventually reverses the direction of the shunt, resulting in Eisenmenger syndrome.
Presentation

History:
The malformation often goes unnoticed for decades because symptoms may be absent and because physical signs are subtle.
Even isolated defects of moderate-to-large size do not generally cause symptoms in infancy and childhood. Occasional cases of CHF and recurrent pneumonia are seen in infancy. Most children are asymptomatic, though some may have easy fatigability and exertional dyspnea. They may be somewhat underdeveloped and prone to respiratory infections. In childhood, the diagnosis is often considered after a heart murmur is detected on routine physical examination or after an abnormal finding is observed on chest radiographs or ECGs.
Symptoms usually take 30-40 years to develop. They are mainly consequences of pulmonary hypertension, atrial tachyarrhythmias, and, sometimes, associated mitral valve disease. Virtually all patients with ostium secundum ASD who survive beyond the 6th decade are symptomatic.
Clinical deterioration in older patients occurs by means of several mechanisms.
First, an age-related decrease in left ventricular distensibility augments the left-to-right shunt.
Second, atrial arrhythmias, especially atrial fibrillation, but also atrial flutter or paroxysmal atrial tachycardia, increase in frequency after the 4th decade and precipitate right ventricular failure.
Third, most symptomatic adults older than 40 years of age have mild-to-moderate pulmonary hypertension in the presence of a persistent large left-to-right shunt; therefore, the aging right ventricle is burdened by pressure and volume overload.
Another mechanism for symptoms is related to clinically significant mitral regurgitation that is seen in about 15% of patients. Its incidence, extent and degree of dysfunction increases with age. These abnormalities have been attributed mainly to the effects of left ventricular cavity deformity on mitral apparatus.
Most common presenting symptom is dyspnea and easy fatigability. Other symptoms include palpitations, syncope, and CHF.
The development of palpitations related to atrial arrhythmias is the most common symptom in adults.

Physical:
The findings depend on the hemodynamic consequences of the left-to-right shunt, which in turn depends on the size of the defect, the diastolic properties of both ventricles, and the relative impedance in pulmonary and systemic circulation.
Blood flow across the ASD does not cause a murmur at the site of the shunt because no substantial pressure gradient is present between the atria.
The patient often has a hyperdynamic right ventricular impulse due to increased diastolic filling and a large stroke volume.
Palpable pulsation of the pulmonary artery and an ejection click can be detected because of a dilated pulmonary artery.
S1 is typically split, and the second component may be increased in intensity, reflecting forceful right ventricular contraction and delayed closure of the tricuspid leaflets.
ASDs with moderate-to-large left-to-right shunts produce a pulmonary outflow murmur that begins shortly after the S1, peaks in early-to-mid systole and that ends before the S2. An associated thrill indicates a large shunt or pulmonic stenosis.
S2 is widely split and fixed because of greatly reduced respiratory variation due to delayed pulmonic valve closure (seen only if pulmonary artery pressure is normal and pulmonary vascular resistance is low). This characteristic abnormality is found in almost all patients with large left-to-right shunts.
Increased right ventricular stroke volume across the pulmonary outflow tract and valve creates a crescendo-decrescendo midsystolic (ejection) murmur. This murmur is usually grade 2 or 3 and is heard in the second interspace at the left sternal border.
Patients with large left-to-right shunts often have a rumbling middiastolic murmur at the lower left sternal border because of increased flow across the tricuspid valve.
In patients with an ostium primum defect and an associated cleft mitral valve, an apical pansystolic murmur of mitral regurgitation may be present. This murmur can be heard along the left sternal border as the jet is directed into the right atrium through the low ASD. Mitral regurgitation murmur can also be heard if valve prolapse is present.
In patients who develop pulmonary hypertension and right ventricular hypertrophy, a right ventricular S4 may be present. In such cases, the midsystolic pulmonic murmur is softer and shorter, the tricuspid flow murmur is not present, the splitting of S2 is narrowed with accentuated pulmonic component and murmur of pulmonic regurgitation may become apparent.
In case of shunt reversal (Eisenmenger syndrome), cyanosis and clubbing may become evident.
Auscultatory findings of the ASD may resemble those of mild valvular, or infundibular, pulmonic stenosis and idiopathic dilatation of the pulmonary artery. These disorders all manifest as a midsystolic (ejection) murmur, but they differ from the ASD by movement of the S2 with respiration, a pulmonary ejection click, or the absence of a tricuspid flow murmur.
Indications

The decision to repair any kind of ASD is based on clinical and echocardiographic information, including the size and location of the ASD, the magnitude and hemodynamic impact of the left-to-right shunt, and the presence and degree of pulmonary hypertension. Elective closure is advised for all ASDs with echocardiographic evidence of right ventricular overload or with a clinically significant shunt (pulmonary vascular resistance [Qp]–to–systemic vascular resistance [Qs] ratio >1.5). Lack of symptoms is not a contraindication for repair. In patients with interatrial septal aneurysm and secundum ASD, spontaneous closure may occur, and patients may be followed up relatively conservatively for a period before repair is advised.

For both children and adults, surgical mortality rates for uncomplicated secundum ASDs are approximately 1-3%. Because of the risk of paradoxical embolization, closure may be recommended, even for patients with small shunts in whom the incidence of CHF, pulmonary hypertension, and arrhythmias is low. However, such closure remains controversial because patients with small defects generally have a good prognosis, and the risk of cardiopulmonary bypass may not be warranted. The benefit of catheter closure of small secundum defects remains to be determined.

Long-term prevention of death and complications is best achieved when the ASD is closed before the age of 25 years and when the systolic pressure in the main pulmonary artery is less than 40 mm Hg. Even in elderly patients with large shunts, surgical closure can be performed at low risk and with good results in reducing symptoms.
Contraindications

Closure of an ASD is not recommended in patients who have severe pulmonary hypertension or severe pulmonary vascular disease (Qp-Qs ratio 0.7 or above) without a clinically significant shunt or in patients who have a reversed shunt with at-rest arterial oxygen saturations of <90% with little or no residual left-to-right shunt. In addition to the high surgical mortality and morbidity risk, closure of the defect may worsen the prognosis. Whether patients whose condition is diagnosed well in the sixth decade of life benefit from surgical closure remains of controversial.

http://emedicine.medscape.com/article/162914-overview

Ventricular Septal Defect

Introduction

A ventricular septal defect (VSD) is a congenital abnormal opening in the ventricular septum that allows communication of blood between the left and right ventricles. VSDs are caused by embryologic malformations of the ventricular septum. They can occur as an isolated lesion or in combination with other congenital cardiac anomalies. The defect can range from a lesion that might require surgery to a miniscule hole in the muscular septum. Blood flow across the defect is typically left to right and depends on the size of the defect and the pulmonary vascular resistance (PVR).
History of the Procedure

In 1950, Bailey first attempted pulmonary artery banding for the treatment of VSDs. Three years later, he attempted direct suture of a VSD using hypothermia and vena caval occlusion. In 1956, Kirklin reported the first cases of direct-vision intracardiac repair of VSDs using the mechanical pump oxygenator. In 1957, Lillehei demonstrated the feasibility of the transatrial approach to VSD repair using cardiopulmonary bypass.
Frequency

VSDs rank first in frequency on all lists of cardiac defects. They account for 25-40% of all cardiac malformations at birth. US and international frequencies are identical—approximately 1-2 cases per 1000 live births. Studies have shown that the prevalence of VSDs has increased in the United States during the past 30 years. A twofold increase in the prevalence of VSD was reported by the Centers for Disease Control and Prevention from 1968-1980. The Baltimore-Washington Infant Study (BWIS) reported a twofold increase in the prevalence of VSD from 1981-1989. The BWIS study reported that the increase is primarily attributed to more sensitive detection through echocardiography.
Etiology

VSDs result from a deficiency of growth or a failure of alignment or fusion of component parts of the ventricular septum. Incomplete closure of the interventricular foramen and failure of the membranous part of the interventricular septum to develop result from failure of tissue to grow from the right side of the fused endocardial cushions and to fuse with the aorticopulmonary septum and muscular part of the interventricular septum.

The increase of alcohol and illicit drug use has been identified as possible risk factors for VSD. The National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention produced data that show maternal marijuana use during the preconception period is associated with an increased risk of simple VSD. The study goes on to show an increase in use correlated with an increase in VSD prevalence.

A twofold increase in the risk of VSD associated with maternal cocaine use during pregnancy was found in a study at Boston City Hospital in 1991. The BWIS further reported correlations between membranous isolated VSD and paternal cocaine use. Abnormal blood flow to the heart due to the vasoconstricting effects of cocaine is a postulated reason for these increases.

Finally, alcohol consumption has also been associated with increased VSD. The BWIS found that maternal alcohol consumption was associated with small muscular VSD. No correlation was found with membranous VSDs. A study from Finland further found that alcohol consumption was associated with a 50% increase in VSDs.

Correlations are not detected between the muscular VSDs and maternal use of NSAIDs or acetaminophen. Such correlations were also not detected between maternal fever and VSDs.
Pathophysiology

The VSD permits a left-to-right shunt to occur at the ventricular level. A left-to-right shunt at the ventricular level has 3 adverse hemodynamic consequences: (1) left ventricular (LV) volume overload, (2) increased pulmonary blood flow, and (3) compromise of systemic cardiac output.

The functional disturbance caused by a VSD depends on the magnitude of the shunt, which is a function of the size of the VSD and the status of the pulmonary vascular bed rather than the location of the VSD. A small VSD with high resistance to flow permits only a small left-to-right shunt. A large interventricular communication allows a large left-to-right shunt only if no pulmonic stenosis or high PVR exists because these factors also determine shunt flow. Quantifying the shunt by the ratio of pulmonary-to-systemic circulation (QP/QS) is useful.

The severity of pulmonary vascular disease correlates to the size of the shunt. In time, as PVR increases, irreversible histologic changes may occur within the pulmonary vascular bed. Untreated, a reversal of the flow occurs, leading to a right-to-left shunt with the development of increasing cyanosis (Eisenmenger complex).

The natural history of VSDs encompasses a wide spectrum, ranging from spontaneous closure to congestive cardiac failure and death in early infancy. The spectrum includes possible development of pulmonary vascular obstruction, right ventricular (RV) outflow tract obstruction, aortic regurgitation, and infective endocarditis.
Presentation

The clinical picture and functional impairment of VSDs primarily depend on the size of the defect, the status of the pulmonary vasculature, and the degree of shunting, and less on the location of the VSD. Note the following features:
A small VSD usually causes no symptoms.
Respiratory distress and mild tachypnea result from abnormal pulmonary compliance due to mild left-to-right shunting.
Because of compromised systemic output and vasoconstriction, infants with moderately sized VSDs may be pale and are often diaphoretic.
Patients with moderately sized VSDs and decreased pulmonary compliance frequently have a history of 1 or more episodes of pneumonia and/or upper respiratory tract infections.
Infants with a large left-to-right shunt often have congestive heart failure and fail to gain weight.
Patients with VSDs complicated by pulmonary hypertension and reversed shunts (ie, Eisenmenger complex) may present with exertional dyspnea, chest pain, syncope, hemoptysis, cyanosis, clubbing, and polycythemia.
Bacterial endocarditis can develop regardless of the size of the VSD and is related to turbulent blood flow through the defect.
The most common physical finding is a harsh grade IV-VI holosystolic murmur. The murmur is best heard along the left sternal border, is usually louder at the third and fourth intercostal spaces, and is widely transmitted over the precordium. The murmur of VSD does not radiate to the left axilla, as with mitral regurgitation, and does not increase in intensity with inspiration, as with tricuspid regurgitation.
Generally, the smaller the defect, the more turbulent the blood flow through it and the louder the murmur. A grade V-VI murmur may be associated with a very high-velocity flow through only a small, hemodynamically insignificant VSD.
A systolic thrill can commonly be palpated in the region of the murmur along the lower left sternal border. A systolic thrill is less common with large VSDs than with moderate or small defects.
Large defects, with appreciable left-to-right shunts, have wide splitting of the S2, which varies with respiration, and the pulmonic component is accentuated.
When the left-to-right shunt is large, a diastolic, low-pitched flow rumble, suggesting increased flow through the mitral valve, is present. This rumble, which is audible at the lower left sternal border, is often associated with LV S3 gallop.
If pulmonary hypertension develops, the holosystolic murmur diminishes and the thrill disappears. In these patients, the pulmonic component of S2 becomes loud, and an RV lift (indicative of RV hypertrophy) may develop. Cyanosis may become evident, and polycythemia follows. A pulmonary ejection sound may also be noted. The murmur of pulmonary insufficiency can develop (ie, Graham Steell murmur).
Supracristal VSDs in the outlet septum may produce murmurs and thrills more prominent in the first or second left intercostal space with radiation upward.
Patients with a supracristal VSD may develop a diastolic blowing murmur of aortic regurgitation. The holosystolic murmur followed immediately by a blowing diastolic murmur may simulate a continuous murmur.
Patients with VSD are especially at risk for endocarditis, pulmonary infection, ventricular arrhythmias, heart failure, and pulmonary hypertension.
Of patients with congenital VSD, 20% have additional cardiac abnormalities. Most abnormalities were detected at the initial assessment stage; however, aortic prolapse and pulmonary stenosis may also develop subsequently.
Aortic regurgitation may result from the high velocity flow beneath a poorly supported right aortic cusp.
Indications

The indications for surgical intervention and its timing may be simple or complex. While many investigators have tried to establish an algorithm for management, the decision to intervene is often a combination of the judgment of pediatric cardiologists and surgeons. The approach must carefully consider the patient's age, symptoms, physiology, and anatomy. Many areas are open to interpretation.
Symptomatic infants with large shunts who cannot be managed medically should undergo closure of the defect.
Surgical repair in patients younger than 6 months is undertaken for control of intractable congestive heart failure, recurrent lower respiratory tract infections, or failure to thrive despite medical treatment.
In children younger than 2 years, prompt surgical repair is indicated if pulmonary hypertension begins to develop before an inoperable predominant right-to-left shunt ensues.
Criteria for surgery in children older than 2 years include presence of symptoms, a QP/QS greater than 2:1, cardiomegaly, or elevated pulmonary artery pressure (PAP).
In adults, surgery is usually recommended if the QP/QS is more than 1.5:1. Once the PVR exceeds 60-70% of systemic vascular resistance and the left-to-right shunt diminishes, closure of the ventricular septal defect (VSD) may no longer be indicated.
Surgery is not indicated in asymptomatic patients with normal findings on chest radiographs and ECGs and a QP/QS of less than 1.5:1.
Patients with subarterial VSD and aortic cusp prolapse, supracristal VSD with aortic regurgitation, or perimembranous VSD with aortic regurgitation are ordinarily referred for surgery to prevent progression of aortic regurgitation.
Even small VSDs should be closed after a single episode of infective endocarditis if the defect remains open once the infection has been cured.
Relevant Anatomy

Ventricular septal defects (VSDs) are classified by the position they occupy in the ventricular septum. The septum is divided into 4 components: the membranous septum, the inlet, the trabecular, and the outlet parts of the muscular septum. (The outlet septum is also called the conal or infundibular septum.) Thus, 4 anatomic types of VSDs exist.
Type I defects are also known as subarterial, outlet, or conal defects. These defects comprise 5% of all VSDs and are located in the outlet portions of the left and right ventricles. The superior edge of the VSD is the conjoined annulus of the aortic and pulmonary valves. Because the aortic and pulmonary valves are in fibrous continuity, this type of defect may also be referred to as doubly committed subarterial. (They are also called juxta-arterial, supracristal, subpulmonary, infundibular, or conoseptal defects.) This VSD is associated with prolapse of the unsupported aortic valve cusps and progressive aortic regurgitation.
Type II defects are also called infracristal, subaortic, perimembranous, or paramembranous defects. These defects are the most common type of VSD, comprising 75% of all VSDs. They occur around the membranous septum and the fibrous trigone of the heart and are associated with a muscular defect at a portion of their perimeter. The defect is near the aortic valve, and the annulus of the tricuspid valve contributes to the rim of the defect. Perimembranous defects are divided into 3 major subtypes according to the adjacent portion of the muscular septum: perimembranous inlet, perimembranous trabecular, and perimembranous outlet.
Type III defects (10% of all VSDs), also called atrioventricular (AV) canal, AV septal, or inlet septal defects, are located in the posterior region of the septum beneath the septal leaflet of the tricuspid valve.
Type IV defects (10% of all VSDs), also called muscular defects, have entirely muscular rims. They may be single but are commonly multiple. Muscular defects may be divided into several categories: inlet, trabecular, central, apical, marginal, and outlet (infundibular). Most commonly, multiple defects occur in the apical trabecular septum. In its most severe form, multiple defects of the ventricular septum are sometimes descriptively referred to as Swiss cheese septum.
Contraindications

A pulmonary-to-systemic vascular resistance ratio greater than 0.9:1 or pulmonary arteriolar resistance greater than 12 Wood units is regarded as an absolute contraindication to surgery.
Pulmonary hypertension is not a contraindication to surgery provided the pulmonary-to-systemic vascular resistance is less than 0.75:1. Furthermore, PVR may be described as reactive when it is lowered by higher inspired oxygen content or vasodilators such as nitric oxide. Nonresponders are described as fixed. Patients whose PVR is reactive may benefit more from repair than those whose PVR is fixed.
A PVR of more than 8 Wood units obtained during cardiac catheterization with pulmonary vasodilatation is a contraindication to surgery.

http://emedicine.medscape.com/article/162692-overview

Patent Ductus Arteriosus

Introduction
History of the Procedure

Galen initially described the ductus arteriosus in the early first century. Harvey undertook further physiologic study in fetal circulation. However, it was not until 1888 that Munro conducted the dissection and ligation of the ductus arteriosus in an infant cadaver, and it would be another 50 years before Robert E. Gross successfully ligated a patent ductus arteriosus (PDA) in a 7-year-old child. This was a landmark event in the history of surgery and heralded the true beginning of the field of congenital heart surgery.
Problem

PDA is a persistent communication between the descending thoracic aorta and the pulmonary artery that results from failure of normal physiological closure of the fetal ductus. In normal birth weight and full-term neonates, the ductus arteriosus (DA) closes within 3 days after birth. However, the DA is patent for more than 3 days after birth in 80% of preterm neonates weighing less than 750 g and its persistent patency is associated with increased morbidity and mortality. Furthermore, in the presence of a significant left-to-right ductal shunt in low birth weight (LBW) neonates, a decreased peripheral perfusion and oxygen delivery occurs.

Although frequently diagnosed in infants, the discovery of a PDA may be delayed until childhood or even adulthood. In isolated PDA, signs and symptoms are consistent with left-to-right shunting. The shunt volume is determined by the size of the open communication and the pulmonary vascular resistance. PDA may exist with other cardiac anomalies, which must be considered at the time of diagnosis. In many cases, the diagnosis and treatment of a PDA is critical for survival in neonates with severe obstructive lesions to either the right or left side of the heart.
Frequency

PDA occurs with an incidence of approximately 1 per 2000-2500 live births, comprising 5-10% of all congenital cardiac disease. Siblings have an increased incidence, suggesting a genetic component. Rubella, in the first trimester of the mother's pregnancy, has been associated with PDA and other congenital anomalies. For unknown reasons, PDA is more common in females by a ratio of 2:1. PDA is common in premature infants and may add significantly to morbidity and mortality.
Etiology

PDA is the result of failure of the fetal ductus arteriosus to constrict and close after birth.
Pathophysiology

In the fetal circulation, the ductus arteriosus is necessary to divert blood flow from the high-resistance pulmonary vascular bed, which receives only 5-8% of the right ventricular outflow, creating a right-to-left shunt. At birth, expansion of the neonatal lungs is associated with an immediate fall in pulmonary vascular resistance. Normal ductal constriction begins at this point and reaches completion in 8-10 hours. A second stage of closure related to fibrous proliferation of the intima is complete in 2-3 weeks. Patency after 3 months is considered abnormal, and treatment should be considered at this juncture, although urgency is seldom necessary.

The ductus is a muscular artery with a thick smooth muscle layer in its medial layer. It contracts and closes within a few days after birth. A balance of factors that cause relaxation and contraction determine the vascular tone of the ductus. Major factors causing relaxation are the high prostaglandin levels, hypoxemia, and nitric oxide production in the ductus. Factors resulting in contraction include decreased prostaglandin levels, increased oxygen partial pressure, increased endothelin-1, norepinephrine, acetylcholine, bradykinin, and decreased prostaglandin E receptors. Increased prostaglandin sensitivity, in conjunction with pulmonary immaturity leading to hypoxia, contributes to the increased frequency of PDA in premature neonates.

Failure of ductus arteriosus contraction in preterm neonates has been suggested to be due to poor prostaglandin metabolism because of immature lungs. Furthermore, high reactivity to prostaglandin and reduced calcium sensitivity to oxygen in vascular smooth muscle cells contribute to contraction of the ductus. The absence of DA contraction in full-term neonates might be due to failed prostaglandin metabolism most likely caused by hypoxemia, asphyxia, or increased pulmonary blood flow, renal failure, and respiratory disorders.

COX-2 (an isoform of COX-producing prostaglandins) induction and expression might also prevent ductal closure. The activation of G protein-coupled receptors EP4 by PGE2, the primary prostaglandin regulating ductal tone leads to ductal smooth muscle relaxation.

During late gestation, the decrease in prostaglandin levels results in constriction of the ductus arteriosus. Thus, the intimal cushions come into contact and occlude the ductus lumen.

A PDA is considered pathological when it persists beyond 3 months of age or is associated with symptoms. Spontaneous closure after 5 months is rare in the full-term infant. Left untreated, patients with a large PDA are at risk to develop Eisenmenger Syndrome, in which the pulmonary vascular resistance can exceed systemic vascular resistance, and the usual left-to-right shunting reverses to a right-to-left direction. At this stage, the pulmonary vascular disease is irreversible, closure of the PDA is contraindicated, and lung transplantation may be the only hope for long-term survival.
Presentation

Signs and symptoms of PDA are the result of left-to-right shunting and are proportional to the magnitude of the blood flow through the ductus.

History

Most patients with PDA present with a machinery murmur and are asymptomatic. Neonates and infants may present with signs of heart failure including tachypnea, diaphoresis, failure to thrive, inability to feed, and irritability. They may also have a history of frequent recurrent pulmonary infections. Adults whose PDA has gone undiagnosed may present with signs and symptoms of heart failure, atrial arrhythmia, or even differential cyanosis limited to the lower extremities, indicating shunting of unoxygenated blood from the pulmonary to systemic circulation.

Physical examination

Patients typically present in good health, with normal respirations and heart rate. If the ductus is moderate or large, widened pulse pressure and bounding peripheral pulses are frequently present, reflecting increased left ventricular stroke volume and diastolic runoff of blood into the initially lower-resistance pulmonary vascular bed. Prominent suprasternal and carotid pulsations may be noted secondary to increased left ventricular stroke volume.

The continuous murmur with a machinery quality is typically loudest at the left upper and midsternal border. In patients with severe heart failure and severe elevation of pulmonary vascular resistance, no audible murmur may be present. Patients with large PDA can develop Eisenmenger pathophysiology and present with cyanosis because of reversed shunting when pulmonary arterial pressures exceed systemic pressure as described earlier.

In neonates, a heart murmur is discovered within the first few days or weeks of life. The murmur is usually recognized as systolic rather than continuous in the first weeks of life and can mimic a benign systolic murmur.

Because of changes in the pulmonary vasculature, in adults, diastolic runoff decreases to the point that only a systolic component may exist.

Furthermore, distinguishing between clinically significant and nonsignificant PDA is important. A clinically significant PDA is characterized by respiratory problems with ventilation difficulties, coupled with pulmonary congestion with tachycardia, bounding pulses, and metabolic acidosis. The left-to-right shunt leads to an increased risk of complications that include intraventricular hemorrhage, narcotizing enterocolitis, chronic lung disease, and death.
Indications

With rare exceptions, the presence of a patent ductus arteriosus (PDA) is an indication for surgical closure. In the infant, repair may be urgent for the symptomatic patient with evidence of cardiac or respiratory failure not adequately controlled with medications, or it may be delayed in the patient who is asymptomatic or well controlled on medical therapy.

Differential diagnoses
Ventricular septal defect
Aortopulmonary window (aortopulmonary fenestration)
Venous hum
Truncus arteriosus
Absent pulmonary valve syndrome
Ventricular septal defect with aortic regurgitation
Ruptured sinus of Valsalva and fistula
Systemic arteriovenous fistula
Coronary artery fistula
Pulmonary arteriovenous fistulae
Bronchial pulmonary artery stenosis
Relevant Anatomy

The patent ductus arteriosus (PDA) connects the pulmonary artery to the descending thoracic aorta, usually 2-10 mm from the aortic origin of the left subclavian artery. It is commonly 5-10 mm long and tends to be shorter in the adult. The aortic orifice tends to be wider and narrows en route to the pulmonary opening.

In the presence of complex congenital heart defects, the usual anatomy of the ductus may not be present. Anatomic abnormalities can vary widely and are common in conjunction with complex aortic arch anomalies. Structures that have been mistaken for the PDA in surgical procedures include the aorta, the pulmonary artery, and the carotid artery. The left recurrent laryngeal nerve typically arises from the vagus nerve just anterior and caudal to the ductus and loops posteriorly around the ductus to ascend behind the aorta en route to the larynx. It is the most commonly injured anatomic structure in ductal ligation. Other less commonly injured structures include the phrenic nerve and the thoracic duct.
Contraindications

The primary contraindication to repair is severe pulmonary vascular disease. If transient intraoperative occlusion of the PDA does not decrease elevated pulmonary arterial pressures with a subsequent increase in aortic pressure, then the closure must be undertaken carefully and may be contraindicated. Closure of the ductus does not reverse preexisting pulmonary vascular disease.

A subset of associated cardiac anomalies—so-called ductal-dependent lesions—depend on flow through the PDA to maintain systemic blood flow. Premature closure of the ductus without concurrent repair of the following defects is contraindicated and may be fatal:
Pulmonary artery hypoplasia
Pulmonary atresia
Tricuspid atresia
Transposition of the great arteries
Aortic valve atresia
Mitral valve atresia with hypoplastic left ventricle
Severe coarctation of the aorta

http://emedicine.medscape.com/article/162796-overview

Tricuspid Stenosis

Introduction
Background

Tricuspid valve dysfunction can result from morphological alterations in the valve or from functional aberrations of the myocardium. Tricuspid stenosis is almost always rheumatic in origin and is generally accompanied by mitral and aortic valve involvement.1

Most stenotic tricuspid valves are associated with clinical evidence of regurgitation that can be documented by performing a physical examination (murmur), echocardiography, or angiography. Stenotic tricuspid valves are always anatomically abnormal, and the cause is limited to a few conditions. With the exceptions of congenital causes or active infective endocarditis, tricuspid stenosis takes years to develop.2,3

Pathophysiology

Tricuspid stenosis results from alterations in the structure of the tricuspid valve that precipitate inadequate excursion of the valve leaflets. The most common etiology is rheumatic fever, and tricuspid valve involvement occurs universally with mitral and aortic valve involvement. With rheumatic tricuspid stenosis, the valve leaflets become thickened and sclerotic as the chordae tendineae become shortened. The restricted valve opening hampers blood flow into the right ventricle and, subsequently, to the pulmonary vasculature. Right atrial enlargement is observed as a consequence. The obstructed venous return results in hepatic enlargement, decreased pulmonary blood flow, and peripheral edema. Other rare causes of tricuspid stenosis include carcinoid syndrome, endocarditis, endomyocardial fibrosis, systemic lupus erythematosus, and congenital tricuspid atresia.4,2,3

In the rare instances of congenital tricuspid stenosis, the valve leaflets may manifest various forms of deformity, which can include deformed leaflets, deformed chordae, and displacement of the entire valve apparatus. Other cardiac anomalies are usually present.1
Frequency
United States

Tricuspid stenosis is rare, occurring in less than 1% of the population. While found in approximately 15% of patients with rheumatic heart disease at autopsy, it is estimated to be clinically significant in only 5% of these patients. The incidence of the congenital form of the disease is less than 1%.
International

Tricuspid stenosis is found in approximately 3% of the international population. It is more prevalent in areas with a high incidence of rheumatic fever. The congenital form of the disease is rare and true incidence is not available.
Mortality/Morbidity

The mortality associated with tricuspid stenosis depends on the precipitating cause. The general mortality rate is approximately 5%.
Race

No racial predisposition is apparent.
Sex

Tricuspid stenosis is observed more commonly in women than in men, similar to mitral stenosis of rheumatic origin. The congenital form of the disease has a slightly higher male predominance.
Age

Tricuspid stenosis can present as a congenital lesion or later in life when it is due to some other condition. The congenital form accounts for approximately 0.3% of all congenital heart disease cases. The frequency of tricuspid stenosis in the older population, due to secondary causes, ranges from 0.3-3.2%.

Clinical
History
Fatigue, due to limited cardiac output, may be present.
Systemic venous congestion leads to abdominal discomfort and swelling. The onset is usually gradual, but it may be rapid if atrial fibrillation or flutter develops. (For related information, see Medscape's Atrial Fibrillation Resource Center).
Dyspnea may be present but is not severe unless concomitant mitral valve disease is present.
Patients may complain about prominent pulsations in the neck.
When tricuspid stenosis occurs concomitantly with mitral stenosis, the decrement of cardiac output to the pulmonary bed may paradoxically diminish the dyspnea, hemoptysis, and orthopnea typically seen with mitral stenosis.
Obtain information regarding preceding rheumatic fever, symptoms of the carcinoid syndrome, and possible congenital abnormalities.
Physical
With sinus rhythm (more common with tricuspid stenosis than with mitral stenosis), the jugular venous pulse increases and the A wave is prominent (may be confused with an arterial pulse).
If atrial fibrillation occurs, the A wave is lost.
Peripheral edema and ascites are frequent.
Without significant mitral pathology, the patient should not be dyspneic and can probably lie flat without symptoms.
A prominent right atrium may be palpable to the right of the sternum. If not obscured by mitral stenosis sounds, a tricuspid opening snap may be heard. A diastolic murmur is audible along the left sternal border or at the xiphoid, which increases with inspiration. Often, tricuspid regurgitation is also present, represented by a holosystolic murmur in a similar location.
The first heart sound may be split widely. The second heart sound may be single. This single sound is due to the inaudible closure of the pulmonary valve from the decrease in blood flow through the stenotic tricuspid valve.
Causes

At least 4 conditions can cause obstruction of the native tricuspid valve. These include (1) rheumatic heart disease, (2) congenital abnormalities, (3) metabolic or enzymatic abnormalities, and (4) active infective endocarditis.

Rheumatic tricuspid stenosis: In this entity, diffuse thickening of the leaflets occurs, with or without fusion of the commissures. The chordae tendineae may be thickened and shortened. Calcification of the valve rarely occurs. The leaflet tissue is composed of dense collagen and elastic fibers that produce a major distortion of the normal leaflet layers.
Carcinoid heart disease: Carcinoid valve lesions characteristically manifest as fibrous white plaques located on the valvular and mural endocardium. The valve leaflets are thickened, rigid, and reduced in area. Fibrous tissue proliferation is present on the atrial and ventricular surfaces of the valve structure.
Congenital tricuspid stenosis: These lesions are observed more commonly in infants. They may manifest as incompletely developed leaflets, shortened or malformed chordae, small annuli, abnormal size and number of the papillary muscles, or any combination of these defects.
Infective endocarditis: Large infected vegetations obstructing the orifice of the tricuspid valve may produce stenosis. This condition is relatively uncommon, even in those who abuse intravenous drugs.
Unusual causes: Rare causes of tricuspid stenosis include Fabry disease and giant blood cysts.
Mimickers of tricuspid stenosis: Several conditions may mimic tricuspid stenosis by obstructing flow through the valve. These conditions include supravalvular obstruction from congenital diaphragms, intracardiac or extracardiac tumors, thrombosis or emboli, or large endocarditis vegetations. In addition, conditions that impair right-sided filling can produce similar symptoms and physical findings. These conditions include constrictive pericarditis and restrictive cardiomyopathy.

http://emedicine.medscape.com/article/158604-overview

Tricuspid Regurgitation

Introduction
Background

Tricuspid regurgitation may result from structural alterations of any one or all of the components of the tricuspid valve apparatus. Components include the leaflets, chordae tendinea, annulus, and papillary muscles or adjacent right ventricular (RV) muscle. The lesion may be classified as primary when it is caused by an intrinsic abnormality of the valve apparatus or as secondary when it is caused by RV dilatation.

Pathophysiology

The pathophysiology of tricuspid regurgitation focuses on the structural incompetence of the valve. The incompetent nature of the valve can result from primary structural abnormalities of the leaflets and chordae or from secondary myocardial dysfunction and dilatation.1

Tricuspid valve insufficiency due to leaflet abnormalities may be secondary to endocarditis or rheumatic heart disease. When due to the latter, it generally occurs in combination with tricuspid stenosis. Ebstein anomaly is the most common congenital form of tricuspid regurgitation.

In tricuspid regurgitation, chronic right ventricular volume overload results in right-sided congestive heart failure (CHF) manifested by hepatic congestion, peripheral edema, and ascites. For more on heart failure, see Medscape's Heart Failure Resource Center.

Frequency
United States

Incidence of tricuspid regurgitation appears to be 0.9%.
International

Incidence of tricuspid regurgitation appears to be less than 1%.
Mortality/Morbidity

The morbidity and mortality of the disease process are secondary to the underlying cause. In rheumatic disease, mortality rates with treatment are less than 3%. In Ebstein anomaly, mortality depends upon the severity of the valvular deformity and the feasibility of correction. Mortality rates with correction are approximately 10%. Tricuspid regurgitation resulting from myocardial dysfunction or dilatation has a mortality of up to 50% at 5 years.
Race

No race predilection is apparent.
Sex

No sex predilection is apparent.
Age

Ebstein anomaly can be detected at birth and during early childhood. In patients older than 15 years, the most common form of tricuspid regurgitation is rheumatic valvular disease. In the adult population, other predisposing factors, including carcinoid, bacterial endocarditis, and CHF, takes precedence.
Clinical
History


The patient with tricuspid regurgitation presents with the signs and symptoms of right-sided heart failure. The spectrum of presenting symptoms is dependent upon whether the condition is secondary to left ventricular (LV) dysfunction. If it is, dyspnea on exertion, orthopnea, and paroxysmal nocturnal dyspnea accompany ascites and peripheral edema as common presenting complaints. Exercise intolerance may also be observed. The patient rarely reports angina, which may be present in the absence of coronary artery disease secondary to RV overload and strain.2

These patients must be questioned regarding intravenous drug use, history of rheumatic fever, and febrile episodes because bacterial endocarditis is a common cause of tricuspid valvular disease.
Physical

S3 gallop is present, and the following physical findings may be found:
Jugular venous distention with a prominent V wave: When present, a pansystolic murmur is heard along the lower left sternal border with inspiratory accentuation.
Diminished peripheral pulse volume secondary to impaired forward blood flow: Patients with this sign may have relative hypotension secondary to therapeutic interventions used to decrease volume overload.
Pulmonary rales if the tricuspid regurgitation is associated with LV dysfunction or mitral stenosis
RV heave and S 4 gallop that increases with inspiration
Ascites
Peripheral edema
Cachexia and jaundice
Atrial fibrillation (For more information on atrial fibrillation, see Medscape's Atrial Fibrillation Resource Center.)
A high-pitched pansystolic murmur (loudest in the fourth intercostal space in the parasternal region). The murmur is usually augmented during inspiration and is reduced in intensity and duration in the standing position and during a Valsalva maneuver. A short, early diastolic flow rumble may be present due to increased flow across the tricuspid valve.

Causes

Pure tricuspid regurgitation can be caused by at least 10 conditions.

Rheumatic heart disease
Tricuspid regurgitation secondary to rheumatic involvement is usually associated with mitral and aortic valve pathology.1
The valve develops diffuse fibrous thickening without commisural fusion, fused chordae, or calcific deposits. Occasionally, the chordae may be mildly thickened by fibrous tissue.
Rheumatic disease is the most common cause of pure tricuspid regurgitation due to deformation of the leaflets.

Endocarditis
This is an important cause of tricuspid regurgitation. Precipitating factors that can contribute to infection of the valve include alcoholism, intravenous drug use, neoplasms, infected indwelling catheters, extensive burns, and immune deficiency disease.
The clinical presentation is often that of pneumonia from septic pulmonary emboli rather than CHF. Heart murmurs are frequently absent and blood cultures may be negative. Annular abscesses are not uncommon.

Ebstein anomaly
This entity is a congenital malformation of the tricuspid valve characterized by apical displacement of the annular insertion of the septal and posterior leaflets and atrialization of a portion of the ventricular myocardium.
Prognosis for these patients depends upon the degree of apical displacement of the tricuspid annulus and the severity of the regurgitation.3

Prolapse (floppy, redundant)
The incidence of floppy tricuspid valve varies from 0.3-3.2%.
The lesion appears to be associated with prolapse of the mitral valve and uncommonly occurs in an isolated fashion.
Histological examination of the floppy tricuspid valve shows alterations on the valve spongiosa.

Carcinoid
Pure tricuspid regurgitation can occur as part of the carcinoid heart syndrome.
Fibrous white plaques form on the ventricular aspect of the tricuspid valve and endocardium, causing the valve to adhere to the RV wall.
Proper coaptation of the leaflets does not occur during systole, resulting in tricuspid regurgitation.4

Papillary muscle dysfunction
Papillary muscle dysfunction may result from necrosis (secondary to myocardial infarction), fibrosis, or infiltrative processes.
Although dysfunction secondary to myocardial infarction is less common than occurs with the mitral valve, the underlying cause must be determined in order to plan treatment.

Trauma
Trauma to the right ventricle may damage the structures of the tricuspid valve, resulting in insufficiency of the structure.5
More commonly it is associated with stab wounds or projectile destruction of the valve.

Connective-tissue diseases
Patients with Marfan syndrome or other connective-tissue diseases (eg, osteogenesis imperfecta, Ehlers-Danlos syndrome) may have tricuspid regurgitation.
Typically, dysfunction of other valves is also observed in the same patient.
The etiology of the regurgitation can be attributed to a floppy tricuspid valve and a mildly dilated tricuspid valve annulus.

Medications
Medications that act via serotoninergic pathways may cause valvular lesions similar to those observed with carcinoid.
Medications used to treat migraine (eg, methysergide), Parkinson disease (eg, pergolide), and obesity (eg, fenfluramine) have been associated with tricuspid regurgitation.

Anatomically normal tricuspid valve
A common etiology of tricuspid regurgitation is dilatation of the RV cavity.
The valve structures are normal; however, because of enlargement of the cavity and dilatation of the annulus, proper coaptation of the leaflets is not possible.
Causes of the dilatation include mitral stenosis, pulmonic stenosis or regurgitation, pulmonary hypertension, dilated cardiomyopathy, and RV failure.

http://emedicine.medscape.com/article/158484-overview

Pulmonic Stenosis

Introduction
Background

Pulmonic stenosis (PS) refers to a dynamic or fixed anatomic obstruction to flow from the right ventricle (RV) to the pulmonary arterial vasculature. Although most commonly diagnosed and treated in the pediatric population, individuals with complex congenital heart disease and more severe forms of isolated PS are surviving into adulthood and require ongoing assessment and cardiovascular care.
Pathophysiology
PS can be due to isolated valvular (90%), subvalvular, or peripheral (supravalvular) obstruction, or it may be found in association with more complicated congenital heart disorders. The characteristics of the various types of PS are described in this section.

Valvular pulmonic stenosis

Isolated valvular PS comprises approximately 10% of all congenital heart disease. Typically, the valve commisures are partially fused and the 3 leaflets are thin and pliant, resulting in a conical or dome-shaped structure with a narrowed central orifice. Poststenotic pulmonary artery dilatation may occur owing to "jet-effect" hemodynamics.

Alternatively, approximately 10-15% of individuals with valvar PS have dysplastic pulmonic valves. These valves have irregularly shaped, thickened leaflets, with little, if any, commissural fusion, and they exhibit variably reduced mobility. The leaflets are composed of myxomatous tissue, which may extend to the vessel wall. The valve annulus is usually small, and the supravalvular area of the pulmonary trunk is usually hypoplastic. Poststenotic dilatation of the pulmonary artery is uncommon. Approximately two thirds of patients with Noonan syndrome have PS due to dysplastic valves.

A bicuspid valve is found in as many as 90% of patients with tetralogy of Fallot, whereas it is rare in individuals with isolated valvar PS.

With severe valvular PS, subvalvular right ventricular hypertrophy can cause infundibular narrowing and contribute to the right ventricular outflow obstruction. This often regresses after correction of valvular stenosis.

With severe PS and decreased right ventricular chamber compliance, cyanosis can occur from right-to-left shunting if a concomitant patent foramen ovale, atrial septal defect, or ventricular septal defect is present.

Subvalvular pulmonic stenosis

Subvalvular PS occurs as a narrowing of the infundibular or subinfundibular region, often with a normal pulmonic valve. This condition is present in individuals with tetralogy of Fallot and can also be associated with a ventricular septal defect (VSD).

Double-chambered right ventricle is a rare condition associated with fibromuscular narrowing of the right ventricular outflow tract with right ventricular outflow obstruction at the subvalvular level.

Peripheral pulmonary stenosis

Peripheral pulmonary stenosis (PPS) can cause obstruction at the level of the main pulmonary artery, at its bifurcation, or at the more distal branches. PPS may occur at a single level, but multiple sites of obstruction are more common. PPS may be associated with other congenital heart anomalies such as valvular PS, atrial septal defect (ASD), VSD, or patent ductus arteriosus (PDA); 20% of the patients with tetralogy of Fallot have associated PPS.

Functional or physiologic PPS is a common cause of a systolic murmur in infants. It occurs in both premature and full-term infants; with time, the pulmonary artery grows, and the murmur usually disappears within a few months.

Poststenotic dilatation occurs with discrete segmental stenosis but is absent if the stenotic segment is long or if the pulmonary artery is diffusely hypoplastic.

PPS is associated with various inherited and acquired conditions including rubella and the Alagille, cutaneous laxa, Noonan, Ehlers-Danlos, and Williams syndromes.

Frequency
United States

PS is a common form of congenital heart disease that occasionally is diagnosed for the first time in adulthood. Isolated valvular PS comprises approximately 10% of all congenital heart disease.
Mortality/Morbidity

Except for critical stenosis in neonates, survival is the rule in congenital PS.

The long-term course of patients with mild PS is indistinguishable from that of the unaffected population. Mild PS does not tend to progress in severity; rather, pulmonic valve orifice size usually increases with body growth. However, untreated severe PS may result in outflow obstruction that progresses over a period of years; 60% of patients with severe PS require intervention within 10 years of diagnosis.

Sex

A slight female predominance exists.
Clinical
History
Most children and adults with mild-to-moderately severe pulmonic stenosis (PS) are asymptomatic.
Those with severe PS may experience exertional dyspnea and fatigue.
In extremely rare cases, patients present with exertional angina, syncope, or sudden death.
Peripheral edema and other typical symptoms occur with right heart failure.
Cyanosis is present in those with significant right-to-left shunt via a patent foramen ovale, atrial septal defect, or ventricular septal defect.
Physical
A precordial heave or a palpable impulse from the RV along the left parasternal border may suggest severe PS. In the left upper sternal border, a systolic thrill may be palpable at the level of the second intercostal space.
In valvular PS, auscultation reveals a normal S1 and a widely split S2, with a soft and delayed P2. Valvular PS typically causes a systolic crescendo-decrescendo ejection murmur in the left upper sternal border that increases with inspiration and radiates diffusely.
In patients with pliable valve leaflets, a systolic ejection click may precede the murmur, distinguished from aortic ejection sounds by its increased intensity on expiration and softening on inspiration. As the severity of PS increases, the ejection murmur increases in intensity, its duration prolongs, and its peak becomes more delayed. No ejection click is heard when dysplasia or severe leaflet thickening immobilizes the valve leaflets, or if the stenosis is above or below the pulmonic valve.
The murmur of PPS may be continuous, softer, and higher pitched.
Mild-to-moderately severe desaturation or frank cyanosis may be noted with right-to-left shunting through a patent foramen ovale, atrial septal defect, or ventricular septal defect.
Causes
See Pathophysiology.

Other forms of acquired pulmonic stenosis
PS is a rare manifestation of rheumatic heart disease, and it follows involvement of the mitral and aortic valves.
Carcinoid may result in development of myxomatous plaques in the RV outflow tract, with distortion and constriction of the pulmonic ring, as well as fusion or destruction of pulmonary valve leaflets, resulting in both stenosis and regurgitation.
Rarely, cardiac tumors can grow on or into the RV outflow tract and cause flow obstruction.
Sinus of Valsalva aneurysms and aortic graft aneurysms are extracardiac entities that can cause PS by external compression.

http://emedicine.medscape.com/article/157737-overview

Pulmonic Regurgitation

Introduction
Background

The pulmonic valve is normally a thin tricuspid structure that prevents blood from regurgitating into the right ventricle once ejected into the low-pressure pulmonary circulation. Pulmonic regurgitation refers to retrograde flow from the pulmonary artery into the right ventricle during diastole. Physiologic (trace-to-mild) pulmonic regurgitation is present in nearly all individuals, particularly in those with advanced age. However, pathologic conditions that produce excessive and clinically significant regurgitation can result in impairment of right ventricular function and eventual clinical manifestations of right-sided volume overload and heart failure. Often, pulmonic regurgitation is not the primary process but a finding secondary to an underlying process such as pulmonary hypertension or dilated cardiomyopathy.

Pathophysiology

Incompetence of the pulmonic valve occurs by 1 of 3 basic pathologic processes: dilatation of the pulmonic valve ring, acquired alteration of pulmonic valve leaflet morphology, or congenital absence or malformation of the valve.
Frequency
United States

Physiologic pulmonic regurgitation is present in nearly all individuals and is a normal echocardiographic finding. Pulmonic regurgitation detected by physical examination is not a normal finding in healthy adults. Congenital pulmonic regurgitation and congenital absence of the pulmonic valve are rare conditions.
International

No difference in international incidence is known.
Mortality/Morbidity

The morbidity and mortality rates associated with pulmonic regurgitation vary considerably, depending on the underlying etiology.
Race

No racial or ethnic predilection exists.
Sex

Differing frequency of pulmonic regurgitation between men and women corresponds to the specific etiology resulting in pulmonic regurgitation.
Age

Except for congenital absence of the pulmonic valve, which is more likely to cause right-sided ventricular decompensation early in life, the age at which clinical symptoms of pulmonic regurgitation occur is variable and is primarily related to the underlying process causing the pulmonic regurgitation.
Clinical
History

Pulmonic regurgitation is seldom clinically significant. However, symptoms of right-sided heart failure can occur when the severity and duration of the regurgitation result in right ventricular enlargement and decompensation. Dyspnea on exertion is the most common complaint. Easy fatigability, light-headedness, peripheral edema, chest pain, palpitations, and frank syncope may occur in patients with any cause of right-sided heart failure and do little to elucidate the etiology of the right-sided failure. Patients who experience these symptoms may attribute them to poor physical fitness or anxiety, delaying evaluation until their condition worsens. In more advanced presentations of right-sided heart failure, abdominal distension secondary to ascites, right upper quadrant pain secondary to hepatic distension, and early satiety may occur.

Other symptoms specific to the underlying disease process causing pulmonic regurgitation may occur. Such disease processes include connective-tissue disease, infective endocarditis, carcinoid heart disease, rheumatic heart disease, and primary or secondary pulmonary hypertension. For example, hemoptysis is generally not associated with pulmonic regurgitation per se, but, in severe pulmonary hypertension causing pulmonic regurgitation, it may occur as a result of the associated pulmonary arteriole rupture and hemorrhage and/or parenchymal inflammation.

Physical
Jugular venous pressure (JVP) is usually increased. Often, an increased A wave is present, but this may be less apparent when significant tricuspid regurgitation with a dominant V wave is also present. When right ventricular enlargement is present, a palpable impulse (lift or heave) is usually present at the left lower sternal border. Palpable pulmonary artery pulsation at the left upper sternal border may be present in the setting of significant pulmonary artery dilatation. With significant pulmonary hypertension, pulmonic valve closure can be palpated.
The pulmonic component of the second heart sound (P2) is inaudible in the absence of a pulmonic valve, whether congenital or secondary to surgical resection. In pulmonic regurgitation due to pulmonary hypertension, P2 is accentuated; with increased right ventricular end-diastolic volume, the ejection time is increased, P2 is delayed, and the S2 split is widened.
A low-pressure regurgitant flow across the pulmonic valve, as occurs when the pulmonary arterial pressure is normal, is heard as a brief, decrescendo early diastolic murmur at the upper left sternal border. It is made louder by squatting or inspiration and softer by Valsalva maneuvers or expiration. An S3 or S4 may be noted at the left mid-to-lower sternal border because of the presence of right ventricular hypertrophy or failure and is augmented by inspiration.
The Graham Steell murmur of pulmonary hypertension is a high-pitched, early diastolic decrescendo murmur noted over the left upper-to-left midsternal area and is a result of high-velocity regurgitant flow across an incompetent pulmonic valve. The regurgitant flow murmur may be present during the whole of diastole because there is a pulmonary-to-right ventricular pressure gradient throughout this time period. Typically, the murmur occurs in severe pulmonary hypertension when the pulmonary artery systolic pressure is more than 60 mm Hg. The quality of this high-pitched early decrescendo diastolic murmur is identical to that of aortic insufficiency. However, the peripheral manifestations of aortic insufficiency are absent. The associated findings of tricuspid regurgitation are frequently present, that is, prominent JVP with surging V waves, holosystolic murmur at the lower left sternal border (louder with inspiration), and enlarged, pulsatile liver.
Causes
Significant pulmonic regurgitation occurs variably as a complication of the following:

Primary pulmonary hypertension (~1 instance per 500,000 cases): This diagnosis can be made only after all other causes have been excluded.
Secondary pulmonary hypertension (multiple causes): This is the most common cause of pulmonic regurgitation in adults.
Tetralogy of Fallot: Especially with congenital absence of the pulmonary valve or postoperative following surgical repair of this condition (eg, pulmonary valvotomy).
Infective endocarditis: Rare, but may occur in an intravenous drug user or an individual with an atrial septal defect and a large left-to-right intracardiac shunt.
Rheumatic heart disease: Pulmonary valve affected following mitral, aortic, and tricuspid valve involvement.
Carcinoid heart disease: See Carcinoid Lung Tumors and Carcinoid Tumor, Intestinal.
Medications: Medications that act via serotoninergic pathways (eg, methysergide, pergolide, fenfluramine).
Disorders that dilate the pulmonic valve ring to create valvular incompetence are the most common cause of pulmonic regurgitation.
Primary or secondary pulmonary hypertension
Dilatation of the pulmonary trunk in Marfan syndrome or Takayasu arteritis
Idiopathic
Acquired disorders that alter pulmonic valve morphology
Rheumatic heart disease: In most cases, the other valves (ie, mitral, aortic, tricuspid) are also substantially affected.
Trauma from a Swan-Ganz catheter: This cause is unusual, but it can result if the catheter tip is withdrawn across the pulmonic valve with the balloon inflated.
Complications related to therapeutic balloon catheter dilatation of a stenotic pulmonic valve (eg, pulmonary balloon valvuloplasty). Such complications are not uncommon; however, in most cases, the degree of regurgitation is clinically insignificant, rendering pulmonic valve balloon catheter dilation a safe and effective treatment for moderate-to-severe pulmonic stenosis in adult and pediatric patients.
Complications of surgical repair of pulmonic stenosis or congenital heart disease, such as tetralogy of Fallot
Syphilis infection
Carcinoid heart disease: The heart is affected in up to 60% of patients in whom carcinoid has metastasized to the liver, most commonly manifesting as valvular disease. In Pellikka and colleagues' 1993 series of 74 patients, the pulmonic valve was involved in 88%. Of those, 49% exhibited significant pulmonic stenosis, and 81% had significant pulmonic regurgitation.1
Congenital disorders that produce an incompetent pulmonic valve
Complete absence of the pulmonic valve
Valvular abnormalities such as fenestrations or redundant leaflets

http://emedicine.medscape.com/article/157639-overview

Mitral Regurgitation

Introduction
Background

Mitral regurgitation (MR) is defined as an abnormal reversal of blood flow from the left ventricle to the left atrium. It is caused by disruption in any part of the mitral valve apparatus, which comprises the mitral annulus, the leaflets (a large anterior [aortic] leaflet and a small posterior [mural] leaflet), the chordae tendineae, and the papillary muscles (anteromedial and posterolateral). The most common etiologies of MR include mitral valve prolapse (MVP), rheumatic heart disease, infective endocarditis, annular calcification, cardiomyopathy and ischemic heart disease. The pathophysiology, clinical manifestations and management of MR differ with the chronicity of the disease and the etiology.
Pathophysiology


MR can be caused by organic disease (eg, rheumatic fever, ruptured chordae tendineae, myxomatous degeneration, leaflet perforation) or a functional abnormality (ie, a normal valve may regurgitate [leak] because of mitral annular dilatation, focal myocardial dysfunction, or both). Congenital MR is rare but is commonly associated with myxomatous mitral valve disease. Alternatively, it can be associated with cleft of the mitral valve, as occurs in persons with Down syndrome, or a ostium primum atrial septal defect.

Acute mitral regurgitation

Acute MR is characterized by an increase in preload and a decrease in afterload causing an increase in end-diastolic volume (EDV) and a decrease in end-systolic volume (ESV). This leads to an increase in total stroke volume (TSV) to supranormal levels. However, forward stroke volume (FSV) is diminished because much of the TSV regurgitates as the regurgitant stroke volume (RSV). This, in turn, results in an increase in left atrial pressure (LAP). According to the Laplace principle, which states that ventricular wall stress is proportional to both ventricular pressure and radius, LV wall stress in the acute phase is markedly decreased since both of these parameters are reduced.

Chronic compensated mitral regurgitation

In chronic compensated MR, the left atrium (LA) and ventricle have sufficient time to dilate and accommodate the regurgitant volume. Thus LA pressure is often normal or only minimally elevated. Because of the left ventricular dilatation via the process of eccentric hypertrophy, TSV and FSV are maintained. Wall stress may be normal to slightly increased as the radius of the LV cavity increases but the end-diastolic LV pressure remains normal. As the LV progressively enlarges, the mitral annulus may stretch and prevent the mitral valve leaflets from coapting properly during systole, thus worsening the MR and LV dilatation.

Chronic decompensated mitral regurgitation

In the chronic decompensated phase, muscle dysfunction has developed, impairing both TSV and FSV (although ejection fraction still may be normal). This results in a higher ESV and EDV, which in turn causes a elevation of LV and LA pressure, ultimately leading to pulmonary edema and, if left untreated, cardiogenic shock.

Frequency
United States

Acute and chronic MR affect approximately 5 in 10,000 people. Mitral valve disease is the second most common valvular lesion, preceded only by aortic stenosis. Myxomatous degeneration has replaced rheumatic heart disease as the leading cause of mitral valvular abnormalities. Mitral valve prolapse has been estimated to be present in 4% of the normal population. With the aid of color Doppler echocardiography, mild MR can be detected in as many as 20% of middle-aged and older adults. MR is independently associated with female sex, lower body mass index, advanced age, renal dysfunction, prior myocardial infarction, prior mitral stenosis, and prior mitral valve prolapse. It is not related to dyslipidemia or diabetes.
International

In areas other than the Western world, rheumatic heart disease is the leading cause of MR.
Clinical
History


Acute mitral regurgitation


When associated with coronary artery disease and acute myocardial infarction (typically, inferior myocardial infarction, which may lead to papillary muscle dysfunction), significant acute mitral regurgitation (MR) is accompanied by symptoms of impaired LV function, such as dyspnea, fatigue, and orthopnea. In these cases, pulmonary edema is often the initial manifestation because of rapid volume overload on the left atrium and the pulmonary venous system.


Chronic mitral regurgitation
Often results from a primary defect of the mitral valve apparatus with subsequent progressive enlargement of the left atrium and ventricle. In this state, patients may remain asymptomatic for years.
Patients may have normal exercise tolerance until systolic dysfunction of the LV develops, at which point they may experience symptoms of a reduced forward cardiac output (ie, fatigue, dyspnea on exertion, or shortness of breath).
With time, patients may feel chest palpitations if atrial fibrillation develops as a result of chronic atrial dilatation. For related information, see Medscape's Atrial Fibrillation Resource Center.
Patients with LV enlargement and more severe disease eventually progress to symptomatic congestive heart failure with pulmonary congestion and edema. At this stage of LV dilatation, the myocardial dysfunction often becomes irreversible. For related information, see Medscape's Heart Failure Resource Center.

Physical

Palpation

Brisk carotid upstroke and hyperdynamic cardiac impulse
Prominent LV filling wave may be present

Auscultation
S 1 may be diminished in acute MR and chronic severe MR with defective valve leaflets.
Wide splitting of S 2 may occur due to early closure of the aortic valve.
S 3 may be present due to LV dysfunction or as a result of increased blood flow across the mitral valve.
P 2 may be accentuated if pulmonary hypertension is present.
Murmur
Quality
Usually high-pitched, blowing
Location
Usually best heard over the apex
Usually radiates to the left axilla or subscapular region
Posterior leaflet dysfunction causes murmur to radiate to the sternum or aortic area
Anterior leaflet dysfunction causes murmur to radiate to the back or top of the head
Duration
Usually holosystolic
May be confined to early systole in acute MR
May be confined to late systole in MVP or papillary muscle dysfunction
S 1 will probably be normal in these cases since initial closure of mitral valve cusps is unimpeded.
A midsystolic click preceding murmur is suggestive of MVP.
Intensity
Little correlation exists between intensity of murmur and severity of MR.
Intensity may be diminished in severe MR caused by LV dysfunction, acute myocardial infarction, or periprosthetic valve regurgitation.

Causes

Acute mitral regurgitation

Coronary artery disease (ischemia or acute myocardial infarction)
Papillary muscle dysfunction
The posteromedial papillary muscle is supplied by the terminal branch of the posterior descending artery and is more vulnerable to ischemic insult than the anterolateral papillary muscle, which is usually supplied by both the left anterior descending and circumflex arteries.
Transient ischemia may result in transient MR associated with angina.
Myocardial infarction or severe prolonged ischemia produces irreversible papillary muscle dysfunction and scarring.
Chordae tendineae dysfunction or rupture
Infectious endocarditis
Abscess formation
Vegetations
Rupture of chordae tendineae
Leaflet perforation
Status post valvular surgery
Trauma
Percutaneous valvuloplasty
Suture interruption
Tumors (most commonly atrial myxoma)
Myxomatous degeneration
Mitral valve prolapse
Ehlers-Danlos syndrome
Marfan syndrome
Systemic lupus erythematosus (Libman-Sacks lesion)
Acute rheumatic fever (Carey Coombs murmur)
Acute global left ventricular dysfunction
Prosthetic mitral valve dysfunction

Chronic mitral regurgitation
Rheumatic heart disease
Systemic lupus erythematosus
Scleroderma
Myxomatous degeneration
Mitral valve prolapse
Ehlers-Danlos syndrome
Marfan syndrome
Calcification of mitral valve annulus
Infective endocarditis (can affect normal, abnormal, or prosthetic mitral valves)
Ruptured chordae tendineae
Trauma
Mitral valve prolapse
Endocarditis
Spontaneous
Rupture or dysfunction of papillary muscles
Coronary artery disease (see causes for acute MR)
Dilation of mitral valve annulus and/or left ventricular cavity (functional MR)
Dilated cardiomyopathies
Aneurysmal dilation of the left ventricle
Hypertrophic cardiomyopathy
Perivalvular prosthetic leak
Congenital
Mitral valve clefts
Mitral valve fenestrations
Parachute mitral valve abnormality
Drug-related
Ergotamine, methysergide, pergolide, anorexiant medications

http://emedicine.medscape.com/article/155618-overview

Mitral Valve Prolapse

Introduction
Background

Mitral valve prolapse (MVP) is the most common valvular abnormality, affecting approximately 2-6% of the population in the United States. MVP usually results in a benign course. However, it occasionally leads to serious complications, including clinically significant mitral regurgitation, infective endocarditis, sudden cardiac death, and cerebrovascular ischemic events. MVP is also the most common cause of isolated mitral regurgitation in the United States, and it is the most common reason for mitral valve surgery.
Pathophysiology

Most patients with MVP are asymptomatic, and their natural history is benign. However, when large, floppy valves or ruptured chordae tendinea result in severe mitral regurgitation, mitral valve surgery or repair may be necessary. Myxomatous proliferation is the most common pathologic basis for MVP, and it can lead to myxomatous degeneration of the loose spongiosa and fragmentation of the collagen fibrils. Disruption of the endothelium may predispose patients to infectious endocarditis and thromboembolic complications. However, the vast majority of patients with MVP have only a minor derangement of the mitral valve structure that is usually clinically insignificant.

Frequency
United States


MVP is thought to be inherited with increased expression of the gene in female individuals (2:1). The most common form of inheritance is autosomal dominant, but X-linked inheritance has been described.

MVP commonly occurs with heritable connective tissue disorders, including Marfan syndrome, Ehlers-Danlos syndrome, osteogenesis imperfecta, and pseudoxanthoma elasticum. In fact, 90% of patients with Marfan syndrome have MVP due to the increased redundancy of the mitral leaflets and apparatus that occur as a result of myxomatous degeneration.

In the 1970s and 1980s, MVP was overdiagnosed because of the absence of rigorous echocardiographic criteria, with a reported prevalence of 5-15%. Subsequently, Levine et al reported that the 2-dimensional echocardiographic characterizations of prolapse, especially on the parasternal long-axis view, are most specific for the diagnosis of MVP.1 Use of these criteria prevent overdiagnosis.

Data from the community-based Framingham study demonstrated that MVP syndrome occurred in only 2.4% of the population.

Mortality/Morbidity

Most patients with MVP are asymptomatic and have a benign prognosis, with survival rates similar to those of the general population. Nonetheless, high-risk patients (ie, those with moderate-to-severe mitral regurgitation) have increased cardiac morbidity and mortality rates, especially if reduced left ventricular systolic function is present.

See Complications.
Sex

MVP occurs more frequently in young women than in men. The most serious consequences of hemodynamically significant mitral regurgitation occur in men older than 50 years.
Age

MVP has been observed in all ages.
Clinical
History

Mitral valve prolapse (MVP) is often diagnosed from the physical examination, when the classic auscultatory finding of a mid-to-late systolic click and/or murmur is appreciated. Alternatively, it may be incidentally diagnosed during routine echocardiography or discovered when complications of MVP manifest.

Most patients are asymptomatic. Symptomatic patients with MVP are separated into 3 categories: (1) those with symptoms related to autonomic dysfunction; (2) those with symptoms related to the progression of mitral regurgitation; and (3) those with symptoms that occur as a result of an associated complication (ie, stroke, endocarditis, or arrhythmia).
Symptoms related to autonomic dysfunction are usually associated with genetically inherited MVP and include the following:
Anxiety
Panic attacks
Arrhythmias
Exercise intolerance
Palpitations
Atypical chest pain
Fatigue
Orthostasis
Syncope or presyncope
Neuropsychiatric symptoms
Symptoms related to progression of mitral regurgitation include the following:
Fatigue
Dyspnea
Exercise intolerance
Orthopnea
Paroxysmal nocturnal dyspnea (PND)
Progressive signs of congestive heart failure (CHF)
ECG usually is normal, but can show nonspecific ST-segment and T wave abnormalities especially in leads II, III, aVF.
MVP is also commonly seen in patients with inheritable connective tissue disorders.

Physical

Clinical characteristics are typically benign in young women, whereas men older than 50 years tend to have serious consequence of mitral regurgitation.

Common general physical features associated with MVP include the following:
Asthenic body habitus
Low body weight or body mass index (BMI)
Straight-back syndrome
Scoliosis or kyphosis
Pectus excavatum
Hypermobility of the joints
Arm span greater than height (which may be indicative of Marfan syndrome)
The classic auscultatory finding is a mid-to-late systolic click, which is present due to the leaflets prolapsing into the left atrium resulting in tensing of the mitral valve apparatus. It may or may not be followed by a high-pitched, mid-to-late systolic murmur at the cardiac apex.
The midsystolic click can vary in intensity and timing, primarily depending on left ventricular volume.
End-diastolic volume can be reduced by performing a Valsalva maneuver or by having the patient stand. These maneuvers result in an early click, which is close to the first heart sound, and a prolonged murmur. In the supine position, especially with the legs raised for increased venous return, left ventricular diastolic volume is increased, resulting in a click later in systole and a shortened murmur.
Patients with MVP most frequently have symptoms of autonomic dysfunction, including easy fatigability, dizziness, and atypical chest pain. This pain is perhaps related to papillary muscle strain (ie, excessive pulling on the left ventricular wall with prolapsed leaflets in the left atrium).
Causes

MVP usually occurs as an isolated entity. As previously mentioned, it also commonly occurs with heritable disorders of connective tissue. MVP has also been described in association with a secundum atrial septal defect.

http://emedicine.medscape.com/article/155494-overview