O. Taoussi^1,, M. Zoubidi¹, M. Mokhtari¹, G. Benouna¹, FZ. Merzouk¹

Chronic degenerative mitral regurgitation (MR) can lead to profound, often asymptomatic, left ventricular (LV) remodeling. We report an exceptional and fatal case of end-stage MR, illustrating a dramatic mismatch between preserved clinical status and catastrophic structural damage on echocardiography. A patient with long-standing, untreated degenerative MR presented with minimal symptoms despite transthoracic echocardiography revealing extreme LV dilatation (end-diastolic diameter 105 mm), severe systolic dysfunction (ejection fraction 10-15%), torrential regurgitation (effective regurgitant orifice area 2.44 cm²), and massive left atrial enlargement. Strikingly, the clinical course was not dominated by heart failure symptoms but terminated abruptly in cardiac arrest due to ventricular fibrillation, likely precipitated by advanced LV dilatation, fibrosis, and electrical instability. This case underscores that end-stage degenerative MR can progress silently to an irreversible, lethal stage dominated by arrhythmic death, reinforcing the critical need for timely intervention before the onset of terminal remodeling.

End-Stage Mitral Regurgitation, Left Ventricular Remodeling, Echocardiography, Ventricular Fibrillation, Sudden Cardiac Death, Clinical Discordance