Painful Left Bundle Branch Block Syndrome Diagnosed in the Emergency Department

Nonischemic angina correlating with intermittent left bundle branch block (LBBB) is described in cardiology literature as "painful left bundle branch block syndrome," with pathophysiology, diagnostic features, and specific therapies proposed based on case series data.

We present the case of a woman who presented to the emergency department (ED) with intermittent chest pain correlating to LBBB on her smartwatch and electrocardiogram and was subsequently diagnosed with painful LBBB syndrome. We review the proposed pathophysiology, diagnostic features, and treatment for the syndrome. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Although chest pain comprises one of the most prevalent ED presentations, this syndrome is not mentioned in emergency medicine literature.