Sudden cardiac death. Fast action is needed.
D016757:Death, Sudden, Cardiac / Q000209:etiology / Q000517:prevention & control*; D004554:Electric Countershock / Q000295:instrumentation; D006323:Heart Arrest / Q000209:etiology / Q000628:therapy; D006801:Humans; D014693:Ventricular Fibrillation / Q000150:complications / Q000628:therapy