Long QT interval in a patient after out-of-hospital cardiac arrest with hypocalcaemia, undergoing therapeutic hypothermia.

A 53-year-old woman was hospitalized after out-of-hospital cardiac arrest due to ventricular fibrillation. Initial electrocardioagram showed sinus rhythm of 117 beats per minute, 452 ms QTc interval, ST-segment depression up to 1 mm in V(2)-V(6), and ST-elevation in lead aVR. Patient was treated with primary coronary angioplasty and therapeutic hypothermia, during which QTc interval prolonged up to 616 ms and Osborn wave was seen in lead V(4), along with elevation of ST-segment in I, II, III, aVF, V(5) and V(6); negative T waves in I, II, aVL, aVF, and V(2)-V(6). Laboratory test results showed hypocalcaemia. After rewarming and ion correction QT abnormalities resolved.