has participant quality cardiac arrest AE severity G1 AE severity G4 AE severity G5 asystole AE 10003586 CTCAE: E10077 WEB: http://www.cardiachealth.org/asystole-and-pulseless-electrical-activity Asystole is the absence of electrical activity in the heart, as evidenced by a flat line on an EKG. Cardiac arrest is a more general term for conditions where the heart is not circulating blood. Ventricular fibrillation (V-fib) or pulseless Ventricular tachycardia (V-tach) are examples of EKG rhythms which also will produce cardiac arrest, but are not asystole. Pulseless electrical activity (PEA) is another catch-all where there is an otherwise survivable EKG, but no blood is circulating. This can be caused by trauma to the heart, or tremendous blood loss, among other reasons. See: https://answers.yahoo.com/question/index?qid=20081027100243AAy0yt4 a cardiac arrest AE where there is no discernible electrical activity on the ECG monitor. YH, MW NCit:C50479 asystole