Unicuspid aortic valve--an uncommon anomaly with a common presentation.
Unicuspid aortic valve (UAV) is a rare congenital anomaly with an estimated incidence of 0.025% found by echocardiography and 5.5% found during aortic valve replacement. (1,2) It usually presents as aortic stenosis and/or aortic regurgitation. It may also co-exist with other congenital anomalies such as aortic aneurysm, aortic dissection, patent ductus arteriosus, and the coarctation of aorta. (3) Here we present a case of UAV with a coexisting ascending aortic aneurysm.
A 26-year-old male with no relevant past medical history presented to hospital after two episodes of syncope. On admission he complained of diaphoresis and lightheadedness. On physical examination his blood pressure was 86/40 mmHg and pulse was 74 beats per minute with a grade 5/6 ejection systolic murmur at the right upper sternal border radiating to carotids. Laboratory findings including troponin were unremarkable. Electrocardiogram showed sinus rhythm. Transthoracic echocardiogram (TTE) showed an ejection fraction of 62%, severely stenotic aortic valve, with mean gradient of 75 mmHg and a peak gradient of 104 mmHg. The peak velocity was 5.1m/s. The calculated aortic valve area by continuity equation was 0.55 cm2. (Figures 1,2) Moderate aortic regurgitation was also noted by color doppler and continuous wave doppler. Computed tomography (CT) scan of the chest without contrast revealed calcification of the aortic valve, compatible with aortic stenosis and aneurysm of the ascending aorta measuring 4.3 cm in diameter. He underwent aortic valve replacement and during surgery a completely fused aortic valve with only a central opening of approximately 4 mm and an ascending aortic aneurysm measured as 4.5 cm was found (Figure 3). Aortic valve was replaced with a 21 mm mechanical valve and resection of ascending aortic aneurysm was performed using 28 mm Dacron tube graft (Figure 4). The patient recovered well without any complications and was discharged home on long-term oral vitamin K antagonists with a follow up in outpatient clinic in one week. On follow up visit, the patient stated he had no further episodes of syncope or lightheadedness, in fact was feeling more energetic. He is now being followed up every three months for the next year.
UAV is a rare congenital anomaly, which has been linked to aortic root dilation in 48%-50% of the cases. This associated aortopathy has been thought to be caused by increased activity of intrinsic tissue structures such as matrix metalloproteinases and protein kinases within the intima and adventitia of the vessel, during embryogenesis, which predisposes these patients to aneurysms. (4,5)
UAV can be detected using various imaging techniques including TTE, transesophageal echocardiography or 3D echocardiography, cardiac CT, or magnetic resonance imaging. (6,7) The 3D echocardiography is noted to have an advantage of viewing detailed valvular anatomy. UAV can be categorized into two types, namely acommissural pin-hole shaped and unicommissural slit-shaped. (8) The acommissural type has no lateral attachment to the aorta with a central orifice, and the unicommissural type has one attachment with an eccentric orifice. (1) The acommissural UAV is associated with severe stenosis which tends to be present at birth and needs surgical repair in infancy or early childhood. The unicommissural type tends to have a larger orifice and thus the patient may remain asymptomatic until adulthood. (1,9) The patient presented had acommissural type of UAV. The present case indicates that any young patient who presents with syncope, aortic stenosis would be considered as a differential diagnosis and warrant further non-invasive workup by echocardiography. New re-constructive surgical approaches for aortic valve repair are currently being studied. (10) We present a very young patient with UAV co-existent with ascending aortic aneurysm, a rare congenital aortic anomaly who had successful aortic valve replacement and ascending aortic repair with graft. This case suggests that any young patient who presents with syncope and unexplainable diaphoresis, aortic stenosis would be a differential. The diagnosis can be quickly made by a careful physical exam and further workup by any available non-invasive modality needs to be performed to confirm the diagnosis.
(1.) Falcone MW, Roberts WC, Morrow AG, et al. Congenital aortic stenosis resulting from a unicommisssural valve. Clinical and anatomic features in twenty-one adult patients. Circulation Volume XLIV, 1971; 44:272-80.
(2.) Novaro GM, Mishra M, Griffin BP. Incidence and echocardiographic features of congenital unicuspid aortic valve in an adult population. J Heart Valve Dis 2003; 12:674-8.
(3.) Mookadam F, Thota VR, Garcia-Lopez AM, et al. Unicuspid aortic valve in adults: a systematic review. J Heart Valve Dis 2010; 19:79-85.
(4.) Boyum J, Fellinger EK, Schmoker JD, et al. Matrix metalloproteinase activity in thoracic aortic aneurysms associated with bicuspid and tricuspid aortic valves. J Thorac Cardiovasc Surg 2004; 127:686-91.
(5.) Jones JA, Stroud RE, Kaplan BS, et al. Differential protein kinase C isoform abundance in ascending aortic aneurysms from patients with bicuspid versus tricuspid aortic valves. Circulation 2007; 116:1144-9.
(6.) Gibbs WN, Hamman BL, Roberts WC, et al. Diagnosis of congenital unicuspid aortic valve by 64-slice cardiac computed tomography. Proc (Bayl Univ Med Cent) 2008; 21:139.
(7.) Debl K, Djavidani B, Buchner S, et al. Unicuspid aortic valve disease: a magnetic resonance imaging study. Rofo 2008; 180:983-7.
(8.) Montealegre-Gallegos M, Shakil O, Jiang L, et al. Unicommissural unicuspid aortic valve. Ann CardAnaesth 2014; 17:40-1.
(9.) Moller JH, Nakib A, Eliot RS, et al. Symptomatic congenital aortic stenosis in the first year of life. J Pediatr 1966; 69:728-34.
(10.) Schafers H-J, Aicher D, Riodionycheva S, et al. Bicuspidization of the unicuspid aortic valve: a new reconstructive approach. Ann Thorac Surg 2008; 85:2012-8.
Dr's. Sitwala, Abusara, Ladia and Panchal are affiliated with the Department of Internal Medicine at the Eastern Tennessee State University. Dr. Raudat is affiliated with the Mountain State Medical Group, Cardiovascular/Thoracic Surgery Dr. Paul is affiliated with the Department of Cardiology at the Eastern Tennessee State University.
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|Author:||Sitwala, Puja; Abusara, Ashraf; Ladia, Vatsal; Panchal, Hemang B.; Raudat, Charles; Paul, Timir K.|
|Publication:||The Journal of the Louisiana State Medical Society|
|Article Type:||Clinical report|
|Date:||Mar 1, 2016|
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