Comparison of conduction pacing, conventional RV pacing, and CRT (biventricular) pacing parameters

Abstract

The comparative analysis of Right Ventricular (RV), Left Bundle Branch (LBB), and Cardiac Resynchronization Therapy (CRT) pacing modalities is pivotal for optimizing patient outcomes in individuals requiring cardiac pacing. This study evaluates key parameters—QRS duration, impedance, sensing, and threshold values—across these pacing methods, highlighting their physiological and clinical impacts. Data were collected during both implant procedures and routine follow-ups. During the implant phase, measurements were obtained in a sterile environment with patients connected to a 12-lead ECG and the EP Tracer system, while pacing lead positioning was guided by signals derived directly from the lead. Key parameters such as pacing threshold, sensing, and impedance were measured using the Medtronic CareLink 2090 programmer. For follow-up data, patients were connected to a 12-lead ECG, and pacing was temporarily disabled to capture native QRS durations, followed by measurements under RV, LV, or LBB pacing.RV pacing, while widely used, often results in prolonged QRS duration, leading to interventricular dyssynchrony and potential long-term adverse outcomes, including pacing-induced cardiomyopathy. The non-physiological activation sequence associated with RV pacing raises concerns about its long-term efficacy. In contrast, LBB pacing represents an innovative approach aimed at achieving more physiological ventricular activation by directly stimulating the conduction system. This method has demonstrated shorter QRS durations compared to RV pacing, mitigating the risks of dyssynchrony and improving ventricular function. However, the technical challenges associated with LBB lead placement highlight the importance of operator experience and patient selection.CRT remains the gold standard for patients with heart failure and wide QRS complexes, particularly those with left bundle branch block (LBBB). The ability of CRT to resynchronize ventricular contraction and reduce QRS duration has been associated with significant improvements in cardiac function, reduced hospitalization rates, and enhanced survival. This study confirms the efficacy of CRT in achieving optimal resynchronization, though it also emphasizes the need for careful patient selection and consideration of anatomical factors that may influence lead placement and overall device performance.The findings of this research underscore the critical role of individualized pacing strategies in optimizing cardiac function and patient outcomes. While LBB pacing offers a less invasive and potentially more physiological alternative to CRT, particularly in patients with narrow QRS complexes, CRT remains indispensable for those with significant dyssynchrony.