A new approach for the recognition of ventricular premature beats

Experimental work is presented to prove that many extrasystoles, classically diagnosed as ventricular premature beats, are not. Most of them correspond to atrial or nodal extrasystoles with some degree of aberrancy. On the other hand, there are ventricular premature beats with normal QRS duration and supraventricular beats with QRS duration greater than 0.12 second. The differentiation of ventricular and supraventricular premature beats must be established by considering the morphology of the extrasystolic complex as well as the time in the cardiac cycle when the premature beat is recorded. Definitions of ventricular extrasystoles from several recent textbooks are reviewed. A new definition is proposed based on experimental work performed in the dog's heart.