Ventricular Echo Beats in the Human Heart Elicited by Induced Ventricular Premature Beats

In three patients, all having as their only hemodynamic abnormality an elevated cardiac index at rest, ventricular echo beats could be elicited by ventricular premature beats induced during regular driving of the ventricle. The occurrence of ventricular echo beats was in each case limited to a small delay-range of the premature beat. Retardation of retrograde conduction of the premature ventricular impulse to the atria appeared to be a necessary condition for the initiation of the echo phenomenon.One of the patients had retardation of antegrade A-V conduction of sinus and premature atrial beats. Atrial echo beats could be elicited in this case.The genesis of the ventricular echo phenomenon in these cases could be explained by the dual conducting system theory.