The bundle of His is a strand of specialized cardiac muscle fibers that carries electrical impulses from the atrioventricular node, located between the atria and ventricles, down through the interventricular septum to the left and right bundle branches, which then distribute the signal throughout the ventricular muscle. While this structure is too small to be directly visualized on echocardiography, its function is reflected in the timing and coordination of ventricular contraction that sonographers observe. Abnormalities of the bundle of His can cause bundle branch blocks, which alter the pattern of ventricular contraction and may be visible on echocardiography as abnormal septal wall motion.
Sonography Term