Physiological versus non-physiological cardiac pacing as assessed by Ultra-high-frequency electrocardiography

Abstract

Background: Permanent cardiac pacing can cause heart failure, with the ventricular dyssynchrony being identified as the main cause for its development. Method: His bundle pacing (HBp), left bundle branch pacing (LBBp), and left ventricular myocardial septal pacing (LVSP) were introduced recently. Their impact on ventricular dyssynchrony was not known. We used ultra-high-frequency ECG (UHF-ECG) to compare ventricular depolarization in these pacing techniques. Results: We showed the nonselective HB pacing produces the same pattern of UHF-ECG ventricular depolarization as selective HB pacing. Next, we showed the nonselective His bundle pacing in the area below the tricuspid valve has the best interventricular synchrony from all other RV pacing locations with myocardial capture. We also compared UHF-ECG-derived parameters of ventricular depolarization during HBp, LBBp, and LVSP and we showed that both pacing types from the left septal area are less physiological than nsHBp. Conclusion: UHF-ECG is an effective tool that can be used in clinical practice to assess the electrical dyssynchrony caused by cardiac pacing. Furthermore, its real-time implementation allows recognizing between physiological vs. non-physiological pacing during an implant procedure.