“Pseudo” Hisian extrasystole arising from the proximal portion of the left bundle branch

The diagnosis of a Hisian extrasystole is based on simple electrocardiographic features and both an extrasystole arising from the His-Bundle (“true” Hisian extrasystole) and also one from the proximal portion of the bundle branch (“pseudo” Hisian extrasystole) would be diagnosed as Hisian extrasystoles [1]. Here we report a case of “pseudo” Hisian extrasystole arising from the proximal portion of the left bundle branch and the successful catheter ablation was achieved in the right coronary cusp.