PAROXYSMAL ATRIAL TACHYCARDIA WITH 2ND-DEGREE ATRIOVENTRICULAR-BLOCK

Paroxysmal atrial tachycardia with atrioventricular block usually indi cates potentially dangerous overdigitalization, and serious heart dise ase is almost universally present, In this report, we describe a patie nt with a structurally normal heart who manifested spontaneously intra -atrial reentrant tachycardia with Wenckebach atrioventricular block i n the absence of medications. In this patient, the longest atrial pace d cycle length that induced atrioventricular nodal block was 390 ms, a nd the atrial cycle length during tachycardia ranged from 360 to 400 m s. The electrophysiologic study in our patient demonstrated that secon d-degree atrioventricular block during atrial tachycardia may occur in patients without structural heart diseases or taking any medication.