Ventricular Fibrillation Caused by Primary Carnitine Deficiency

Primary carnitine deficiency (PCD) is a rare but potentially life-threatening genetic disorder if left untreated. Although some patients remain asymptomatic lifelong, a few patients present with hepatic encephalopathy, hypoglycemia, cardiomyopathy, dysrhythmia, and even sudden death.

A 25-year-old woman with PCD collapsed suddenly while eating lunch. Bystander cardiopulmonary resuscitation (CPR) was performed for 8 min, with automated external defibrillation once before admission. Upon arrival at our emergency department (ED), she was unresponsive without a pulse or spontaneous breathing. The initial heart rhythm on the electrocardiogram monitor was ventricular fibrillation (VF). The medical staff continued CPR with defibrillation for sustained VF. Return of spontaneous circulation (ROSC) was achieved after a total resuscitation time of 14 min, with defibrillation twice after cardiac arrest. The heart rhythm after ROSC was atrial fibrillation, with a rapid ventricular rate initially and subsequent progression to sinus tachycardia with diffuse ST segment depression and a prolonged QT interval. Her low carnitine level was consistent with her underlying disease. Cardiac magnetic resonance imaging and sonography for detection of cardiomyopathy showed no significant findings. With carnitine supplementation for a few days, her plasma carnitine level returned to 30 μM, with no recurrence of ventricular dysrhythmia. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: PCD is rare but could be life-threatening, and compiling detailed histories may help emergency physicians to determine the cause of sudden cardiac death after resuscitation. This information may be used to correct potential underlying problems and prevent recurrence of the condition after treatment.