Atypical termination of simultaneous sino-atrial and atrio-ventricular Wenckebach type conduction caused by atrial premature beats

Abstract

This is a case report of a patient with group beating characterized by progressively shortening P-P intervals and at the same time gradually increasing P-R intervals showing R-P/P-R interval reciprocity due to the simultaneous occurrence of sino-atrial (S-A) Wenckebach and atrio-ventricular (A-V) Wenckebach-like periodicities.All group beatings are terminated by atrial premature beats elicited by a critical P-P interval shortening during S-A Wenckebach type conduction preventing the typical termination of Wenckebach periods.

Key Words:

• sino-atrial Wenckebach periodicity
• atrio-ventricular Wenckebach periodicity
• atrial vulnerability