ABSTRACT
Ventricular rhythms are those which arise from the ventricles, that is, below the level of the atrioventricular node. Like atrial and atrioventricular junctional ectopic beats, ventricular ectopic beats (VEB) appear earlier than expected. VEBs are also called ventricular extrasystoles, ventricular premature complexes, ventricular premature beats or premature ventricular contractions. Multiple VEBs which share the same QRS complex morphology originate from a single focus within the ventricles and are therefore called unifocal. VEBs can be harmless, particularly when the heart is structurally normal, but can also be associated with more hazardous arrhythmias, especially when heart disease is present. Accelerated idioventricular rhythm is essentially a slow form of ventricular tachycardia, with a heart rate of less than 120 beats/min. It occurs when an ectopic focus within the ventricles starts firing with a rate just higher than that of the sinoatrial node — this ventricular focus then takes over the cardiac rhythm.
