Asymmetric Myocardial Hypertrophy and Post-exercise Malaise: A Diagnostic Trap Not to Be Overlooked

Abstract

Asymmetric myocardial hypertrophy with dynamic obstruction during the post-exercise recovery phase is a rare complication that can occur in patients suffering from chronic hypertension. We report the case of a 60-year-old man with a 20-year history of hypertension and poor treatment adherence, without a family history of hypertrophic cardiomyopathy (HCM) or sudden death. He presented with recurrent episodes of malaise occurring immediately after stopping a routine physical effort. Clinical examination revealed no particular abnormalities. Electrocardiogram (ECG) showed left ventricular hypertrophy, while transthoracic echocardiography (TTE) revealed asymmetric myocardial hypertrophy with an interventricular septum measuring 14 mm, without intraventricular gradient at rest. Holter ECG showed no significant findings. A stress echocardiogram revealed a significant increase in the intraventricular gradient, reaching 150 mmHg during the recovery phase. Due to the inefficacy of maximum-dose beta-blocker therapy, septal alcohol ablation was performed after the temporary implantation of an external pacemaker to prevent potential atrioventricular block. Post-procedure echocardiography showed a marked reduction in the intraventricular gradient from 83 mmHg to 42 mmHg during the post-recovery phase. This case illustrates an atypical form of post-exercise obstructive hypertrophic cardiomyopathy in a patient with chronic hypertension. Septal artery alcoholization led to significant hemodynamic improvement, requiring close follow-up to monitor clinical progression and assess the potential need for permanent cardiac pacing.