Ace-of-Spades Morphology in Apical Hypertrophic Cardiomyopathy With Exertional Syncope and Nonsustained Ventricular Tachycardia: A Case Report

Apical hypertrophic cardiomyopathy (ApHCM), also known as Yamaguchi syndrome, is an uncommon phenotypic variant of hypertrophic cardiomyopathy characterized by predominant hypertrophy of the left ventricular apex and a distinctive ace-of-spades ventricular configuration.A 41-year-old man with a family history of sudden cardiac death presented after an episode of exertional syncope while playing soccer.Electrocardiography showed sinus rhythm with marked T-wave inversion across the precordial leads.Transthoracic echocardiography demonstrated preserved left ventricular systolic function with mid-apical hypertrophy, while cardiac magnetic resonance imaging confirmed the apical hypertrophic phenotype.Twenty-four-hour ambulatory electrocardiographic monitoring documented four episodes of nonsustained ventricular tachycardia (NSVT), with a maximum ventricular rate of 198 beats/minute and a longest episode of approximately 26 seconds.Coronary angiography showed no significant obstructive coronary artery disease.Following individualized sudden cardiac death risk assessment, a dual-chamber transvenous implantable cardioverter-defibrillator was placed for primary prevention, and the patient remained asymptomatic during follow-up while receiving beta-blocker therapy.This case highlights the value of integrating electrocardiographic findings, multimodality cardiac imaging, ambulatory rhythm monitoring, and individualized arrhythmic risk assessment in patients with ApHCM presenting with exertional syncope and NSVT.