Bundle of His

The bundle of His (Latin fasciculus atrioventricularis ), named after the internist Wilhelm His, is a part of the conduction system. It is located distal to the Atrioventrikularknotens towards the apex.

Anatomy

The 0.5 to 0.8 cm long bundle of His pierced as normally only muscular bridge between the atria and ventricles, the heart skeleton. It is divided into right and left legs ( bundle branch ) extending right and left of the interventricular septum and leak into the Purkinje fibers.

Histology

Histologically, the His - bundle of a special collection of heart muscle cells. These have the ability, the excitement continues to direct and spontaneous depolarization, the frequency in humans at 20-30 beats per minute is much lower than in the sinus node ( Node sinuatrialis ) or the atrioventricular node ( Node atrioventricularis ).

Function

In the sinus node, the excitement arises and passes to the atrioventricular node. Exists between the two nodes is no direct connection, so that the excitation transfer takes place via cardiomyocytes. From there, the energization to the Bundle of His and thence over the bundle branch in the Purkinje fibers. All other components of the conduction system have the ability to spontaneous depolarization. As in the sinus node impulse formation runs the faster he urges all other parts of the conduction system to its higher frequency, so that their ability in the normal case does not apply. However, if the sine and the atrioventricular node fails, the bundle of His is a distinct rhythm of 20-30 stimulations per minute. This is also called a ventricular escape rhythm.

Dysfunction

A malfunction, for example, the His bundle block. This is a heart rhythm disorder by ischemic, inflammatory or primary degenerative disease of the His bundle. A very rare disorder in newborns, except after cardiac surgery, junctional ectopic tachycardia or the His bundle tachycardia. It is elektrokardiografisch characterized by a tachycardia with normal chamber complexes in atrioventricular dissociation. In addition, it is based on an airport situated in His bundle ectopic focus.