A Wenckebach periodicity at the mitral isthmus lesion has rarely been reported. We described a case presenting conduction recovery with Wenckebach periodicity at the mitral isthmus lesion after achieving the posterior mitral isthmus block. These findings demonstrate an early reconnection of mitral isthmus lesion, and an arrhythmogenic substrate that can lead to development of reentrant tachycardia, that is, peri-mitral atrial flutter.
