A Narrow QRS Is Not Always Normal

Hidenori Matsusaka

doi:10.1016/j.jaccas.2021.04.046

A Narrow QRS Is Not Always Normal

JACC Case Rep. 2021 Sep 1;3(11):1387-1389. doi: 10.1016/j.jaccas.2021.04.046.

Author

Hidenori Matsusaka¹

Affiliation

¹ Department of Cardiovascular Medicine, Matsuyama Red Cross Hospital, Matsuyama, Japan.

Abstract

A narrow QRS complex is a hallmark of a normal beat, although this common assumption is questioned in the findings of the present case. This electrocardiographic challenge investigates the unique mechanism of a narrow QRS and the clinical importance of discovering this phenomenon. (Level of Difficulty: Intermediate.).

Keywords: LBBB, left bundle branch block; PVC, premature ventricular contraction; RBBB, right bundle branch block; bundle branch block; fusion beat; narrow QRS; ventricular parasystole.