Left ventricular diverticulum: A case report and differential diagnosis in an asymptomatic woman.

Left ventricular diverticulum is a rare congenital cardiac anomaly characterized by a myocardial outpouching that typically contracts synchronously with the left ventricle. It is usually incidentally detected and may mimic other ventricular outpouchings with distinct clinical and prognostic implications. We report the case of a 68-year-old woman referred for evaluation of systemic hypertension without prior cardiovascular disease. Transthoracic echocardiography raised suspicion of an interventricular communication due to an apparent septal discontinuity and hypertrophic moderator band. Cardiac magnetic resonance (CMR) performed on a 1.5-T system using cine balanced steady-state free precession, T2-weighted fat-suppressed sequences, and late gadolinium enhancement imaging excluded an interventricular defect. CMR instead demonstrated a left ventricular outpouching with a narrow neck, preserved myocardial wall thickness, and synchronous systolic contraction. No late gadolinium enhancement was present. An incidental thin membranous structure in the right atrium was consistent with partial cor triatriatum dexter. Given preserved biventricular function and absence of symptoms, a conservative strategy with clinical and imaging follow-up was adopted. The patient remained stable during follow-up. CMR is the reference modality for characterization of left ventricular diverticulum and reliable differentiation from other ventricular outpouchings, including aneurysm, pseudoaneurysm, myocardial cleft, and double-chambered left ventricle.