When a left bundle branch block appears on an ECG, the next step is usually an echocardiogram. This noninvasive imaging test shows whether the heart structure looks normal.

Let’s take a look. LAFB occurs when the anterior fascicle of the left bundle branch can no longer conduct action potentials. Review how to diagnose this on an ECG here.

However, unlike in the presence of a left bundle branch block, myocardial ischemia and infarction can easily be detected on ECG when a RBBB is present (see anterior and inferior wall MI examples).

Dr. Keith Roach DEAR DR. ROACH: I am a 66-year-old woman who recently had an ECG prior to my knee surgery. The interpretation I received stated that I had an abnormal ECG with a “left anterior ...

No new left bundle branch block occurred after hospital discharge. In multivariate analysis, predictors of persistent left bundle branch block were greater ventricular depth of valve implantation and ...

We proposed a rate-dependent left bundle branch block as the mechanism responsible for the development of progressive widening of QRS complexes by atrial overdrive pacing in our patient. In normal ...

1 Zhang W, Huang J, Qi Y, et al. Cardiac Resynchronization Therapy by Left Bundle Branch Area Pacing in Patients with Heart Failure and Left Bundle Branch Block. Heart Rhythm. 2019; 16 (12):1783-1790.