Giant deep vein thrombus complicating endovascular cooling therapy after cardiac arrest in a boy with hypertrophic cardiomyopathy.

Mild hypothermia therapy (33-36 °C) is useful in preventing anoxic brain injury occurring after return of spontaneous circulation among survivors of cardiac arrest. Adverse events generally include bleeding, pneumonia, bradycardia, and deep vein thrombosis (DVT). However, one rare complication is huge DVT. We recently encountered a boy with ventricular fibrillation due to hypertrophic cardiomyopathy complicated by huge DVT from bilateral common femoral veins close to the hepatic vein during endovascular cooling therapy via his femoral vein. We successfully managed this case without any complications after infusion of unfractionated heparin to maintain a relatively high activated partial thromboplastin time. <Learning objective: We should be more careful in screening for deep vein thrombosis before and after endovascular cooling therapy.>.