Arrhythmias, Cardiac [Disease/Finding] Cardiac Complexes, Premature [Disease/Finding] Cardiac Complexes, Premature Cardiac Complex, Premature Premature Cardiac Complexes Cardiac Complexes, Premature C0340464 M0008072 29717002 Extrasystoles C2532 Premature Beats 1022048 D005117 A group of cardiac arrhythmias in which the cardiac contractions are not initiated at the SINOATRIAL NODE. They include both atrial and ventricular premature beats, and are also known as extra or ectopic heartbeats. Their frequency is increased in heart diseases. N0000001177 Premature Cardiac Complex Extrasystole Ectopic Heartbeats