Premature ventricular contraction, also called ventricular extrasystole (VES), is a cardiac rhythm abnormality which is characterized by premature contractions of the myocardium. VES can be atrial or supraventricular, meaning that it concerns a premature contraction of an atrium, or ventricular, in which case the ventricle is responsible for early contraction. VES often goes unnoticed, but can sometimes trigger a sensation of palpitations. Isolated, VES has no impact on health. It is discovered during a cardiac auscultation or finding a slight irregularity when taking a pulse, and an electrocardiogram confirms its existence. In the absence of underlying heart disease, no treatment is necessary.