Improvement in ECG parameters predictive of sudden death in patients with ventricular dysfunction and left bundle branch block after cardiac resynchronization through His Bundle pacing

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Electrocardiographic (ECG) parameters predictive of sudden death have been described in patients with ventricular dysfunction. Cardiac resynchronization therapy (CRT) in patients with left bundle branch block (LBBB), in addition to improve the left ventricular ejection fraction (LVEF), can correct part of them, which could have an important impact prognostic at follow-up. Repolarization changes in patients resynchronized via permanent His Bundle pacing (p-HBP) have not been described yet. Methods We designed a prospective descriptive study of patients with LBBB and CRT indication proposed for CRT by p-HBP. We analyzed different ECG patterns of sudden death (QT interval, corrected QT interval, QT interval dispersion, Tpeak-Tend, Tpeak-Tend dispersion, Tp-Te/QT ratio, rdT / JT index, T wave voltage, T wave duration) and the changes of them at 6-month follow-up after His resynchronization. Results We included 21 patients (57.1% male, 70 [63.5-80] years). 90.5% had hypertension, 57.1% diabetes mellitus and 66.7% dyslipidemia. 90.5% had structural heart disease (median LVEF 38 [30-52.5] %); 52.9 % had non-ischemic cardiomyopathy, being the principal cause of the dysfunction in these patients the dyssynchronipathy caused by LBBB. Other causes of cardiomyopathy were hypertensive cardiomyopathy (5.9%), valvulopathy (11.8%) and pacing induced cardiomyopathy (11.8%). 66.7% were resynchronized with dual chamber pacemakers, 28.6% with tricameral defibrillator and 4.8% with tricameral pacemaker. ECG parameters predictive of sudden death basally and at 6-month follow-up are summarized in table 1. All predictors improved in the follow-up with statically significant differences. Fig 1 shows basal (A) and 6-month follow-up (B) changes in repolarization parameters. Conclusion There is an improvement in the ECG parameters predictive of sudden death in patients with LBBB resynchronized via p-HBP. CRT through p-HBP could improve the risk of sudden death.