Title : Incidental detection of quadricuspid aortic valve on coronary CT angiography: A multimodality imaging case
Abstract:
Introduction: Quadricuspid aortic valve (QAV) is an exceedingly rare congenital cardiac malformation, with an estimated incidence of 0.008% to 0.043%. It is primarily characterized by the presence of four functional cusps, which often leads to progressive aortic regurgitation (AR) due to incomplete leaflet coaptation. While often asymptomatic during early life, it frequently manifests in the fifth or sixth decade with symptoms related to hemodynamic dysfunction.
Case Presentation: A 62-year-old female with a long-standing history of hypertension presented with recurrent palpitations and exercise intolerance. Initial cardiovascular assessment via transthoracic echocardiography (TTE) iniki separate clinical centers revealed mild-to-moderate aortic regurgitation and a dilated ascending aorta (39-40 mm); however, the valve’s structural morphology was reported as unremarkable. Due to the patient's symptoms and the need to exclude coronary artery disease, coronary CT angiography (CTA) was performed. CTA successfully identified a quadricuspid aortic valve with four equal-sized leaflets (Hurwitz & Roberts Type A), forming a characteristic "X" shaped coaptation during diastole. To further quantify the valvular dysfunction, cardiac magnetic resonance (CMR) imaging was utilized. CMR confirmed the quadricuspid structure and, through phase-contrast sequences, accurately measured a regurgitant fraction of 15%, correlating with moderate AR. Furthermore, CMR provided a definitive assessment of the non-aneurysmal yet dilated ascending aorta. Following these advanced imaging findings, a targeted echocardiographic re-evaluation by a senior consultant confirmed the QAV diagnosis, which had been overlooked in initial screening.
Conclusion: This case underscores the diagnostic challenges of QAV, particularly when symmetric leaflet morphology leads to false-negative results on routine TTE. It highlights the indispensable role of Coronary CTA not only for coronary evaluation but also for comprehensive valvular assessment. Multimodal imaging, combining the anatomical precision of CT with the quantitative functional gold standard of CMR, is crucial for the accurate diagnosis and long-term management of rare congenital valvular anomalies.
