Type A Quadricuspid Aortic Valve, Rarer Than a Four-Leaf Clover: An Example of Availability Heuristic

Abstract

The natural history of a quadricuspid aortic valve (QAV) is poorly understood due to the extreme rarity of the condition. Given its rarity there is an innate availability heuristic, which can lead to misdiagnosis or delayed diagnosis, as described here. Incidence rates vary between 0.00028–1%, with conflicting gender predominance. Classically, patients present with aortic regurgitation (AR) between 40–60 years of age and require surgery. Approximately 80% of patients with a QAV will have structurally normal hearts; the remaining 18–20% have cardiac anomalies or connective tissue disorders. Presentations include palpitations, chest pain, heart failure (HF), or sudden cardiac death. Classily, patients present with decompensated heart failure and stigmata of AR [ [1] Yuan SM. Quadricuspid aortic valve: a comprehensive review. Braz J Cardiovasc Surg. 2016;31(6):454–60. Google Scholar , [2] Tsang MY, Abudiab MM, Ammash NM, Naqvi TZ, Edwards WD, Nkomo VT, et al. Quadricuspid aortic valve: characteristics, associated structural cardiovascular abnormalities, and clinical outcomes. Circulation. 2016;133(3):312–9. Google Scholar ]. Despite presenting with “classic” symptoms of a QAV, the case that follows demonstrates availability heuristic as a cognitive bias leading to a delayed diagnosis. Retrospectively, the QAV was apparent on early imaging, including transthoracic echocardiography and cardiac magnetic resonance imaging. This paper serves as a reminder of QAV as a pathological entity, its natural history, and its appearance on multiple imaging modalities as well as intraoperative photography for reference.