Bachmann's bundle
Encyclopedia
Bachmann's bundle, also known as the anterior interatrial band, is a broad band of atrial muscle that runs just behind the ascending aorta
and connects the top of the right atrium
with the top of the left atrium
. Bachmann's bundle is, during normal sinus rhythm, the preferential path for electrical activation of the left atrium. It is therefore considered as part of the atrial conduction system of the heart
.
, which is located in the right ventricle near the superior caval vein. From there, the electrical activation spreads over the right atrium. There are at least four different locations where the activation can pass to the left atrium. Apart from Bachmann's bundle these are the anterior interatrial septum, posterior interatrial septum, and the coronary sinus
.. Because it originates close to the sinoatrial node
and consists of long parallel fibers, Bachmann's bundle is, during sinus rhythm, the first of these connections to activate the left atrium.
, converging in the region near the coronary sinus
. Atrial automaticity foci are within the atrial conduction system. The concentration of converging conduction tracts near the coronary sinus results in considerable automaticity activity originating in that area.
Ascending aorta
The ascending aorta is a portion of the aorta commencing at the upper part of the base of the left ventricle, on a level with the lower border of the third costal cartilage behind the left half of the sternum; it passes obliquely upward, forward, and to the right, in the direction of the heart’s...
and connects the top of the right atrium
Right atrium
The right atrium is one of four chambers in the hearts of mammals and archosaurs...
with the top of the left atrium
Left atrium
The left atrium is one of the four chambers in the human heart. It receives oxygenated blood from the pulmonary veins, and pumps it into the left ventricle, via the mitral valve.-Foramen ovale:...
. Bachmann's bundle is, during normal sinus rhythm, the preferential path for electrical activation of the left atrium. It is therefore considered as part of the atrial conduction system of the heart
Heart
The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...
.
Interatrial conduction
The normal cardiac rhythm originates in the sinoatrial nodeSinoatrial node
The sinoatrial node is the impulse-generating tissue located in the right atrium of the heart, and thus the generator of normal sinus rhythm. It is a group of cells positioned on the wall of the right atrium, near the entrance of the superior vena cava...
, which is located in the right ventricle near the superior caval vein. From there, the electrical activation spreads over the right atrium. There are at least four different locations where the activation can pass to the left atrium. Apart from Bachmann's bundle these are the anterior interatrial septum, posterior interatrial septum, and the coronary sinus
Coronary sinus
The coronary sinus is a collection of veins joined together to form a large vessel that collects blood from the myocardium of the heart. It is present in all mammals, including humans...
.. Because it originates close to the sinoatrial node
Sinoatrial node
The sinoatrial node is the impulse-generating tissue located in the right atrium of the heart, and thus the generator of normal sinus rhythm. It is a group of cells positioned on the wall of the right atrium, near the entrance of the superior vena cava...
and consists of long parallel fibers, Bachmann's bundle is, during sinus rhythm, the first of these connections to activate the left atrium.
Bachmann's bundle and the atrial conduction system
Besides Bachmann's bundle, the other three conduction tracts that constitute the atrial conduction system are known as the anterior, middle, and posterior tracts, which run from the sinoatrial node to the atrioventricular nodeAtrioventricular node
The atrioventricular node is a part of the electrical control system of the heart that coordinates heart rate. It electrically connects atrial and ventricular chambers...
, converging in the region near the coronary sinus
Coronary sinus
The coronary sinus is a collection of veins joined together to form a large vessel that collects blood from the myocardium of the heart. It is present in all mammals, including humans...
. Atrial automaticity foci are within the atrial conduction system. The concentration of converging conduction tracts near the coronary sinus results in considerable automaticity activity originating in that area.