Sinus of Valsalva Aneurysm

Introduction
Background

John Thurnam first described sinus of Valsalva aneurysm (SVA) in 1840. Hope further described it in 1939. SVA is usually referred to as a rare congenital anomaly. A congenital SVA is usually clinically silent but may vary from a mild, asymptomatic dilatation detected in routine 2-dimensional echocardiography to symptomatic presentations related to the compression of adjacent structures or intracardiac shunting caused by rupture of the SVA into the right side of the heart.1 Approximately 65-85% of SVAs originate from the right sinus of Valsalva, while SVAs originating from noncoronary (10-30%) and left sinuses (<5%) are exceedingly rare.2
Pathophysiology

Congenital SVA is caused by a dilation, usually of a single sinus of Valsalva, from a separation between the aortic media and the annulus fibrosus. A deficiency of normal elastic tissue and abnormal development of the bulbus cordis have been associated with the development of SVA.3 Other disease processes that involve the aortic root (eg, atherosclerotic aneurysms, syphilis, endocarditis, cystic medial necrosis, chest trauma) may also produce SVA, although this usually involves multiple sinuses. Rupture of the dilated sinus may lead to intracardiac shunting when a communication is established with the right atrium (Gerbode defect [10%]) or directly into the right ventricle (60-90%). Cardiac tamponade may occur if the rupture involves the pericardial space.1
Frequency
United States

SVA was present in 0.09% of cadavers in a large autopsy series and ranged to 0.14-0.23% in a Western surgical series.4 Two-dimensional echocardiography is likely to determine a higher incidence of SVA.
International

SVA is more prevalent in Asian surgical series (0.46-3.5%) and correlates with more supracristal ventricular septal defects (~60%).5
Mortality/Morbidity

The true natural history of SVA is unclear. Clinical complications from SVA are often the initial presentation of SVA (see Complications).

Associated structural defects in congenital SVAs included supracristal or perimembranous ventricular septal defect (30-60%), bicuspid aortic valve (15-20%) and aortic regurgitation (44-50%). Approximately 10% of patients with Marfan syndrome have some form of SVA. Less commonly observed anomalies include pulmonary stenosis, coarctation, and atrial septal defects.
Rupture of SVA (with progressive heart failure and left-to-right shunting or endocarditis) is the main cause of death and rarely occurs before age 20 years in congenital SVA.

Race

Race differences in SVA are unclear, although a higher frequency was observed in the Asian surgical series.
Sex

Male-to-female ratio is 4:1, including frequencies of both ruptured and unruptured SVA.
Age
Unruptured SVA is usually asymptomatic and is often detected serendipitously by routine 2-dimensional echocardiography, even in patients older than 60 years.
Most ruptured SVAs occur from puberty to age 30 years and are often diagnosed or presented clinically at this age.
A retrospective review of an institutional database identified 86 patients who underwent SVA repair from 1956-2003 found the median age to be 45 years (range 5-80 y).6
Clinical
History

Approximately 25% of reported cases of sinus of Valsalva aneurysm (SVA) are clinically asymptomatic, unruptured SVA detected by routine 2-dimensional echocardiography. Rupture of the aneurysmal sac may occur spontaneously, precipitated by exertion, trauma, or cardiac catheterization.

A ruptured SVA progresses in 3 stages as described by Blackshear and colleagues:9
Acute chest or right upper quadrant pain
Subacute dyspnea on exertion or at rest (heart failure syndrome) with progressive or acute onset
Progressive cough, dyspnea, edema, and oliguria
Atypically, SVA presents with infective endocarditis, which may originate at the edges of the aneurysm.
Palpitations or syncope may present secondary to obstruction of the left or right ventricular outflow tract.
Dyspnea is by far the most common presenting symptom.
Physical

Unruptured SVA is often asymptomatic and has almost no physical signs. When SVA ruptures, few specific signs of left-to-right shunting may become apparent, and these are often indistinguishable from coronary arteriovenous fistula. Clinical suspicion followed by prompt echocardiographic confirmation is key to diagnosis.

A loud, superficial, "machine-type" continuous murmur is accentuated in diastole in as many as 40% of patients.
A palpable thrill along the right or left lower parasternal border is occasionally noticeable.
Bounding pulses are occasionally present.
In one series, approximately 44% of the patients had associated aortic regurgitation.6

Causes
Primary causes - Congenital
Secondary causes
Atherosclerosis
Syphilis
Cystic medial necrosis or Marfan syndrome
Blunt or penetrating chest injury
Infective endocarditis
Associated congenital defects
Ventricular septal defect
Aortic insufficiency
Coarctation

http://emedicine.medscape.com/article/158160-overview