Transient Cardiac Dysfunction Due to New-Onset Mitral Chordal Rupture With Concomitant Congenital Absence of the...

BACKGROUND Congenital absence of the right coronary artery (RCA) is a rare anomaly often identified incidentally. We report a case of transient left ventricular systolic dysfunction followed by recovery of ejection fraction and new-onset mitral chordal rupture, which became the primary driver of pronounced N-terminal pro-B-type natriuretic peptide (NT-proBNP) elevation. The coexistence of 2 distinct pathologies complicated causal attribution; we discuss proposed mechanisms while recognizing their limitations. CASE REPORT A 58-year-old woman presented with exertional chest pain. At initial admission, she exhibited sinus tachycardia, elevated NT-proBNP (910 pg/mL), and reduced left ventricular ejection fraction (LVEF; 43% [M-mode]) with hypokinesis of the anterior wall and anteroseptum. Symptoms improved with anti-ischemic therapy. Three weeks later, LVEF recovered to 56% (biplane Simpson method), but NT-proBNP increased to 2440 pg/mL. Echocardiography revealed rupture of a small chord of the anterior mitral leaflet with mild-to-moderate regurgitation and elevated filling pressures (E/e'=13.8). Coronary angiography demonstrated congenital absence of the RCA ostium, with an enlarged left circumflex artery supplying the RCA territory and no evidence of atherosclerotic stenosis. Retrospective quantitative mitral regurgitation indices from archived images were examined. Management was conservative; symptoms resolved and NT-proBNP levels decreased during follow-up. CONCLUSIONS In patients with rare coronary anomalies, newly acquired common valvular disease may dominate the clinical presentation. Transient systolic dysfunction and subsequent chordal rupture occurred in our patient; a direct causal relationship remains speculative. Multimodality imaging is essential to accurately attribute hemodynamic changes and guide therapy. Long-term surveillance of coronary anatomy and valve function is recommended.