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Electrophysiological delineation of the specialized conduction system under cardiotomy and its clinical role

T Tamiya, T Yamashiro, T Matsumoto

    Japanese Circulation Journal
    |October 1, 1982
    PubMed

    Insights

    Identifying the His bundle

    Area of Science:

    • Cardiac Electrophysiology
    • Congenital Heart Surgery
    • Anatomy

    Background:

    • The specialized conduction system's anatomy is crucial for preventing conduction disturbances during congenital heart defect repair.
    • Accurate intraoperative localization of the His bundle and its branches is essential for minimizing iatrogenic injury.

    Purpose of the Study:

    • To electrophysiologically delineate the specialized conduction system in patients undergoing cardiotomy for congenital heart defects.
    • To correlate electrophysiological findings with anatomical landmarks to improve surgical safety and reduce conduction abnormalities.

    Main Methods:

    • Electrophysiological mapping was performed during cardiotomy in 64 patients with ventricular septal defect (VSD), tetralogy of Fallot (TOF), and transposition of the great arteries (TGA).
    • Histological studies were conducted for confirmation of electrophysiological findings.
    • Specific deflection patterns were analyzed in relation to anatomical structures like the muscle of Lancisi (ML) or its equivalent (LES).

    Main Results:

    • A superficial His bundle location was identified in large VSDs (types II/III), correlating with a high incidence of conduction disturbance.
    • Distinct electrophysiological characteristics were observed in TOF, aligning with the His bundle's anatomical course.
    • The muscle of Lancisi (ML) or its equivalent (LES) was identified as a reliable landmark for the right bundle branch (RBB) course, aiding in surgical navigation.

    Conclusions:

    • The muscle of Lancisi (ML) or its equivalent (LES) can serve as a practical landmark for the right bundle branch (RBB) during congenital heart surgery.
    • Utilizing these landmarks has led to a significant reduction in surgically induced complete right bundle branch block.
    • Understanding variations in the conduction system's course is vital for refining surgical techniques and diagnostic accuracy.

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