COMPARATIVE ANALYSIS OF LONG-TERM OUTCOMES FOLLOWING THE STIMULATION OF CARDIAC CONDUCTION SYSTEM AND RIGHT VENTRICULAR PACING IN PATIENTS WITH BRADYARRHYTHMIAS

Abstract

Introduction. Right ventricular myocardial pacing induces asynchronous ventricular contraction, potentially resulting in pacing-induced cardiomyopathy and adverse long-term clinical outcomes. Conduction system pacing is a physiological alternative to right ventricular myocardial pacing. The objective of this study is to analyze the long-term outcomes of the conduction system pacing in comparison with right ventricular myocardial pacing in patients requiring permanent ventricular pacing and who have preserved initial left ventricular ejection fraction (≥ 50%). Materials and methods. 48 patients with indications for permanent ventricular pacing were selected for comparative analysis. Of these, 18 patients had cardiac conduction system pacing and 30 patients had right ventricular myocardial pacing. Permanent pacemaker implantation in both groups of this study was performed from 2012 to 2022. Patients in both groups had to meet the following selection criteria for this study: 1) preserved systolic function of the left ventricle at the time of pacemaker implantation (≥ 50%); 2) total percentage of ventricular pacing from the time of implantation had to be not less than 90%.
 Results. The observation period was 35.3 ± 37 months in the conduction system pacing group and 46 ± 28.73 months in the right ventricular pacing group. Since the time of pacemaker implantation, pacing-induced cardiomyopathy occurred in 7 (23%) patients in the right ventricular pacing group and in none in the conduction system pacing group. The mean left ventricular ejection fraction at the control visit was significantly lower in the right ventricular pacing group (51.59 ± 8.55 vs. 58.64 ± 4.58%, p =.004). A significant reduction in global longitudinal strain was observed in the right ventricular pacing group compared to the conduction system pacing group (14.22 ± 3.66 vs. 18.49 ± 2.5%, p = <.001). Paced QRS width was significantly greater in the right ventricular pacing group (152.32 ± 18.13 vs. 119.12 ± 8.8 ms, p <.001). Conclusions. Applying new physiological methods of cardiac pacing enables to avoid the negative consequences of an asynchronous pattern of ventricular activation during conventional right ventricular pacing.