Definition: 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.
Synonyms (terms occurring on more labels are shown first): extrasystoles, extrasystole, premature beats, ectopic beats, extra systoles, extra-systoles
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