Abstract
BACKGROUND: Mitral valve prolapse (MVP) is an etiologically heterogeneous disorder. Early diagnosis and prompt treatment of the underlying disease are of great significance. Herein, we present a rare case of MVP caused by anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA). CASE PRESENTATION: A 22-year-old female presented with a 16-year history of anterior mitral leaflet prolapse. However, she had never experienced any discomfort before. At a routine follow-up, a transthoracic echocardiogram showed anterior mitral leaflet prolapse (A2) with moderate mitral regurgitation, and a retrograde blood flow from an extremely dilated left coronary artery (LCA). Further coronary angiography and coronary computed tomography angiography confirmed the diagnosis of ALCAPA. She subsequently underwent successful LCA reimplantation and concomitant mitral valve replacement. Intraoperatively, her mitral annulus was mildly dilated, anterior mitral valve leaflet appeared markedly thickened with rolled edges, and a chordae tendineae connecting the anterior leaflet (A2) was ruptured and markedly shortened. CONCLUSIONS: ALCAPA is a rare and potentially life-threatening congenital coronary artery anomaly that may cause mitral valve prolapse. Echocardiogram is an important screening tool for this disorder.