Sudden Cardiac Arrest From Heat Stroke: Hidden Dangers of Hot Yoga

A healthy 35-year-old woman, 12 weeks postpartum, was in her hot yoga class when she suddenly became unresponsive. Cardiopulmonary resuscitation (CPR) was started on the patient promptly. Emergency Medical Services arrived 5 minutes into initiation of CPR. Examination revealed warm skin, dilated pupils, and frank blood foaming from her mouth. Rhythm was consistent with ventricular fibrillation. Forty-five minutes of CPR was performed prior to return of spontaneous circulation, after which the patient was placed on vasopressor support. Vitals 80 minutes after initiation of CPR revealed a core body temperature of 36.6°C. The patient remained unresponsive postresuscitation, with the rest of the examination remarkable for bloody drainage in the endotracheal tube. Postresuscitation labs revealed creatinine 1.06, hemoglobin 12.2 g/dL, platelet 103/mm³, and creatinine kinase 21,000 IU/L. Electrocardiogram post arrest showed normal sinus rhythm with no signs of ischemia or QT prolongation. Chest computed tomography demonstrated alveolar hemorrhage. Echocardiogram showed an ejection fraction of 40% with diffuse hypokinesis. The next day, patient's hematological indices were as follows: hemoglobin 7.9 g/dL, international normalized ratio 1.8, partial thromboplastin time 69, fibrinogen 80 mg/dL, and D-dimer >35 mg/dL, consistent with disseminated intravascular coagulation. The patient was administered blood products, with improvement in disseminated intravascular coagulation parameters. There was no evidence of hemolysis, as suggested by an unremarkable peripheral smear.