[Ventricular hypertrophy and pre-excitation: a diagnostic clue to PRKAG2-related cardiomyopathy]

PRKAG2-related cardiomyopathy is a metabolic phenocopy of hypertrophic cardiomyopathy characterized by ventricular hypertrophy, pre-excitation, and supraventricular arrhythmias, frequently leading to misclassification. We report the case of a 44-year-old man with a maternal family history of hypertrophic cardiomyopathy and long-standing atrial fibrillation. Cardiac magnetic resonance showed asymmetric hypertrophy, extensive late gadolinium enhancement, and early adverse remodeling, suggesting an overlap phenotype between hypertrophic cardiomyopathy and arrhythmogenic left ventricular cardiomyopathy. After primary prevention cardiac defibrillator implantation, genetic testing revealed the heterozygous PRKAG2 c.1024G>A, p.(Glu342Lys) variant, of maternal origin and classified as pathogenic by the local laboratory. Re-evaluation of the baseline ECG demonstrated a short PR interval, ventricular pre-excitation, and right bundle branch block, allowing diagnostic reclassification. This case report highlights the importance of an integrated clinical perspective and of recognizing ECG red flags in order to avoid diagnostic errors is in hypertrophic phenotypes.