Quadricuspid Aortic Valve: Report of Two Cases and Brief Review

Transthoracic echocardiography and its limitations in the diagnosis of congenital supernumerary aortic valve in a Thoroughbred

Aortic valve malformation is a common congenital abnormality reported in human medicine. The malformation is characterised by an increased or decreased number of cusps. Anatomical variations of the aortic valve that have been documented in humans include unicuspid, bicuspid, quadricuspid and quinticuspid valves. Two reports described a quadricuspid aortic valve in horses associated with either a ventricular septal defect (VSD) or tetralogy of Fallot. In this case report we describe the clinical and echocardiographic findings of a horse with a quadricuspid aortic valve as single congenital abnormality, referred with history of exercise intolerance and an episode of paroxysmal atrial fibrillation. Limitations and risks of misdiagnosis that can be encountered with transthoracic echocardiography are also discussed. The reported case highlights the importance of echocardiographic screening in asymptomatic patients as congenital heart disease can be present without obvious cardiac signs. As advanced imaging on the equine thorax is still far from future possibilities for adult horses, this report may help to reach an accurate diagnosis with similar cases.

Case Series of Quadricuspid Aortic Valve

Three patients presented with different symptoms to the emergency department. Further imaging of their hearts displayed an abnormal variant of their aortic valve called a quadricuspid aortic valve (QAV). There are seven types of QAVs, from type A to G, with varying presenting symptoms. The most common complication is aortic regurgitation. The management of QAV is based on these presenting symptoms and complications. Surgical valve repair or replacement is indicated when a QAV becomes symptomatic or a QAV results in ventricular remodeling, which can lead to ventricular dysfunction. Successful surgical repair of QAVs has been shown with both tricuspidization and bicuspidization methods.

Two Consecutive Cases of Quadricuspid Aortic Valve and a Review of 149 Cases

The quadricuspid aortic valve (QAV) is a rare congenital anomaly that typically is unrelated to other cardiac anomalies. It usually is discovered incidentally through imaging modalities such as echocardiogram or computed tomography angiogram, during surgery, or autopsy. Some patients with QAV develop aortic regurgitation and, rarely, other cardiovascular complications like aortic aneurysm. Due to its rarity, it is difficult to characterize these patients or standardize management. However, review of case reports can be very useful in rare medical conditions such as QAV. In this manuscript, in addition to presenting two cases of QAV, the authors reviewed 149 cases of QAV from 2010 to 2020 from published case studies and series in order to gain a better insight into the characteristics of the patient population with QAV and its management.