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His bundle electrogram after intracardiac repair of tetralogy of Fallot. Analysis of data in 59 patients

T J Hougen, M Dick, M D Freed

    The American Journal of Cardiology
    |March 1, 1978
    PubMed

    Insights

    His bundle electrograms reveal that prolonged H-V intervals after tetralogy of Fallot repair correlate with poor hemodynamic outcomes. Normal H-V intervals indicate a good outcome, regardless of other conduction abnormalities.

    Area of Science:

    • Cardiology
    • Electrophysiology
    • Pediatric Cardiac Surgery

    Background:

    • Tetralogy of Fallot repair can lead to conduction abnormalities.
    • His bundle electrograms provide detailed information on cardiac conduction pathways.

    Purpose of the Study:

    • To correlate His bundle electrogram findings with postoperative electrocardiograms in patients after tetralogy of Fallot repair.
    • To assess the relationship between His-bundle intervals and hemodynamic outcomes.

    Main Methods:

    • His bundle electrograms were recorded in 59 patients post-intracardiac repair of tetralogy of Fallot.
    • Electrograms were analyzed for A-H and H-V intervals and correlated with electrocardiogram findings and hemodynamic results.

    Main Results:

    • Group A (normal ECG or RBBB) showed normal A-H and H-V intervals.
    • Group B (bifascicular block) had normal A-H but prolonged H-V intervals.
    • Groups C (trifascicular block) and D (transient complete heart block) exhibited prolonged H-V intervals, with Group C also showing prolonged A-H intervals.
    • A normal H-V interval was associated with good hemodynamic results, while a prolonged H-V interval indicated poor results.

    Conclusions:

    • The H-V interval is a critical indicator of conduction status after tetralogy of Fallot repair.
    • Prolonged H-V intervals are linked to adverse hemodynamic outcomes, highlighting their prognostic significance.

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