From the Guidelines
The Bundle of His is located posteriorly and inferiorly in relation to the atrioventricular (AV) valve in a transitional atrioventricular (AV) canal, with its position affected by the abnormal anatomy of the AV canal. This location is critical due to the abnormal activation sequence of the ventricles resulting from the displacement of the bundle of His and the left bundle branch posteriorly 1. The AV node, from which the Bundle of His emerges, is positioned posterior and inferior to the coronary sinus, influencing the path of the Bundle of His through the heart's fibrous skeleton. Key points about the location and relation of the Bundle of His to the AV valve in a transitional AV canal include:
- The Bundle of His emerges from the AV node, which is located posterior and inferior to the coronary sinus 1
- The Bundle of His and the left bundle branch are displaced posteriorly due to the abnormal anatomy of the AV canal 1
- This displacement affects the normal activation sequence of the ventricles, leading to potential conduction abnormalities
- The location of the Bundle of His in relation to the AV valve is crucial for understanding the risks and challenges associated with surgical interventions in this area, particularly in patients with complete or partial AVSD.
From the Research
Location of the Bundle of His
The location of the Bundle of His in relation to the atrioventricular (AV) valve in a transitional atrioventricular (AV) canal is not directly addressed in the provided studies. However, some studies provide information on the location of the Bundle of His in relation to other cardiac structures.
Relation to Cardiac Structures
- The penetrating bundle of His is located at the level of the tricuspid septal leaflet (TSL) 2.
- The branching bundle of His is situated 1.9±1.5 mm inferior to the TSL 2.
- The Bundle of His is also related to the mitral valve leaflet (MVL) and the muscular interventricular septum, but the exact location in a transitional AV canal is not specified 2.
Clinical Relevance
- The location of the Bundle of His is important for procedures such as slow pathway ablation in atrioventricular nodal reentrant tachycardia 3, 4.
- High-output His-bundle pacing can be used to localize the His bundle in difficult-to-ablate AV junctions 5.
- The introduction of His bundle electrography has relaunched interest in cardiac arrhythmias and the Bundle of His as a target of diagnostic and therapeutic procedures 6.