Left bundle branch block

A delay or blockage of electrical impulses to the left side of the heart.

Overview

Left bundle branch block sometimes makes it harder for the heart to pump blood efficiently through the circulatory system.

Symptoms

Most people don't have symptoms. If they occur, they include fainting or a slow heart rate.

Treatments

If there's an underlying condition, such as heart disease, that condition needs treatment. A pacemaker also can relieve symptoms as well as prevent death.