Refractory ventricular fibrillation caused by caffeine intoxication.

A 30-year-old female with no history of cardiac or systemic disease presented with incessant ventricular fibrillation (VF) after an intake of 12g of over-the-counter caffeine tablets for a suicidal purpose. Her VF was refractory, and repeated defibrillations were needed to attain a recovery of sinus rhythms. We then performed percutaneous cardiopulmonary support and therapeutic hypothermia to stabilize her circulation and prevent anoxic brain damage, respectively. A blood examination revealed an extremely high concentration of caffeine (172mg/L). She fully recovered 16days after her admission. Our findings reveal the potentially lethal arrhythmogenic nature of caffeine.