Inclusive Anatomy
Structure:
The atrioventricular bundle is a specialized component of the cardiac conduction system that provides the only normal electrical connection between the atria and the ventricles. It originates from the atrioventricular (AV) node and traverses the fibrous skeleton of the heart, passing along the membranous portion of the interventricular septum. [1] The fibrous skeleton consists of dense connective tissue that electrically insulates the atria from the ventricles while providing structural support for the heart’s valves and conduction pathways.[2]
After descending through the membranous interventricular septum, the atrioventricular bundle divides into two main branches. The right bundle branch conducts electrical impulses to the subendocardial conduction network of the right ventricle, while the left bundle branch distributes impulses to the subendocardial branches of the left ventricle. [1] Through this branching arrangement, the atrioventricular bundle ensures coordinated activation of the ventricular myocardium.
Function:
The primary function of the atrioventricular bundle is to transmit electrical impulses from the atria to the ventricles. This transmission is essential for synchronizing atrial and ventricular contractions and maintaining an effective cardiac rhythm. During normal cardiac activity, atrial contraction precedes ventricular contraction, allowing efficient ventricular filling before blood is propelled into the pulmonary and systemic circulations. [3]
Disruption of conduction within the atrioventricular bundle can impair impulse transmission, resulting in conduction delays or blocks. Such disturbances may lead to arrhythmias, bradycardia, or irregular ventricular rhythms, conditions that may require clinical evaluation and intervention. [4]
References:
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Moore KL, Dalley AF, Agur AMR. Clinically Oriented Anatomy. 6th ed. Lippincott Williams & Wilkins; 2010.
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Anderson RH, Ho SY. The morphology of the specialized atrioventricular junctional area: the evolution of understanding. Pacing Clin Electrophysiol. 2002;25(6):957-966. https://pubmed.ncbi.nlm.nih.gov/28613768/
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Feher J. The heart as a pump. In: Quantitative Human Physiology. Elsevier/Academic Press; 2012:446-454.
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Patra C, Zhang X, Brady MF. Physiology, bundle of His. In: StatPearls; 2023.
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