Abstract

Double-chambered left ventricle (DCLV) is a rare congenital anomaly mimicking aneurysm or pseudoaneurysm. We report two cases: a 50-year-old male with 20-year history of presumed apical aneurysm (normal coronaries) and a 64-year-old female with pseudoaneurysm in dilated cardiomyopathy (LVEF 25%, LBBB-induced). Cardiac magnetic resonance (CMR) confirmed DCLV in both, revealing a fibromuscular ridge dividing LV chambers. Case 1 (male) demonstrated novel subendocardial fibrosis (3% scar burden) confined to the distal chamber on late gadolinium enhancement (LGE). Case 2 (female) showed preserved accessory chamber contractility without fibrosis. CMR provided definitive differentiation through ridge visualization, chamber contractility assessment, and tissue characterization, guiding conservative management with rhythm surveillance.