Ventricular Fibrillation and Cardiomyopathy in Propionic Acidemia

Propionic acidemia (PA) is a rare autosomal recessive metabolic disorder, typically presenting in infancy. Cardiac involvement in adults is uncommon and underrecognized. A previously healthy 20-year-old man suffered an out-of-hospital cardiac arrest caused by ventricular fibrillation. Initial evaluation revealed dilated cardiomyopathy, elevated lactate and ammonia levels, and increased propionyl-L-carnitine. Genetic testing identified biallelic pathogenic variants in the PCCB gene, confirming PA. He was managed with a subcutaneous implantable cardioverter-defibrillator, carnitine supplementation, and dietary protein restriction, showing favorable recovery. This case illustrates a rare late-onset presentation of PA with isolated cardiac symptoms. Such cases highlight the need to consider metabolic cardiomyopathy in young patients with unexplained ventricular arrhythmias and systemic metabolic disturbances.