Concealed Wenckebach Phenomenon in Left Bundle Branch Associated With Chest Pain.

BACKGROUND

Painful left bundle branch block (LBBB) syndrome is a rare cause of chest pain associated with intermittent LBBB.

CASE SUMMARY: We report the case of a 68-year-old man who experienced chest pain during a treadmill test. The temporal relationship between chest pain and the concealed Wenckebach phenomenon in the left bundle branch, along with the absence of documented myocardial ischemia, strongly suggested a diagnosis of painful LBBB syndrome. The patient underwent up-titration of a β-blocker.

DISCUSSION: The chest pain in painful LBBB syndrome is thought to be related to dyssynchrony in myocardial contraction caused by intermittent depolarization disturbances. Although rare, the Wenckebach phenomenon can complicate conduction in the bundle branches, leading to intermittent LBBB.