Extrasístole a premature ventricular contraction or a heart rhythm disorder. It consists of a heartbeat advance to the normal heart rate of any person and is considered a harmless type of arrhythmia. This person will perceive it as an increase in palpitations, as if the heart skip a beat. The heart has an electrical conduction mechanism that generates the heartbeat. When the beat starts off the automatic system, an ectopic beat occurs. If the source is in the atria (upper chambers of the heart), it is called atrial extrasystole; if it occurs in the ventricles (lower chambers) is called premature ventricular contraction. It is very important to maintain the heart rate and, for that reason, have a clearing mechanism that makes for a few milliseconds, not stimulated again. This system makes a new extrasístole not accelerate again. However, this "protection" pauses or short break after "turn the heart." No serious or pause or extrasístole. The pause is a protective mechanism that is activated until normal heart rhythm restarts.