Retrograde Wenckebach phenomenon induced by right ventricular pacing.

Retrograde Wenckebach phenomenon, occurring between the paced ventricles and the atria, developed in a patient with acute anterior myocardial infarction and ventricular dysfunction. This report has summarized previous investigations on ventriculoatrial conduction and their application to this case. With paced ventricular beats, VA conduction may occur but VA conduction time is longer than AV conduction time at similar heart rates. Progressive degrees of VA block develop at the AV node as the heart rate speeds. VA conduction may occur in the presence of complete AV block. Concealed VA conduction to the AV node supresses AV conduction.