Left ventricular volumes and function in successful and failed His-BundLe Pacing. A comparative prospective study.

Area of Science:

• Cardiology
• Cardiac Electrophysiology
• Cardiovascular Imaging

Background:

• Limited evidence suggests His bundle pacing (HBP) may preserve cardiac structure and function better than right ventricular pacing (RVP).
• Further research is needed to confirm the long-term benefits of HBP compared to RVP.

Purpose of the Study:

• To compare the long-term effects of successful His bundle pacing (HBP) versus right ventricular pacing (RVP) on cardiac structure and function.
• To evaluate the incidence of pacing-induced cardiomyopathy (PICM) in patients undergoing HBP versus RVP.

Main Methods:

• Prospective study of 68 patients with baseline ejection fraction (EF) ≥50% undergoing HBP attempt (successful HBP group or failed RVP group).
• Two-dimensional (2D) and three-dimensional (3D) echocardiography performed at baseline and 6 months after pacing with >20% ventricular pacing burden.
• Analysis included EF, global longitudinal strain (GLS), and incidence of PICM (EF drop ≥10% and EF <50%).

Main Results:

• After 6 months, RVP group showed significant decrease in 2D EF (-3.86%) and 3D EF (-5.71%), while HBP group showed no change (p<0.001).
• GLS significantly increased in RVP group, but remained unchanged in HBP group (p<0.016).
• PICM occurred in 14% of RVP patients versus 0% of HBP patients (p=0.025).

Conclusions:

• Successful HBP superiorly preserves left ventricular systolic function compared to RVP, despite high ventricular pacing burden.
• HBP is associated with a significantly lower incidence of pacing-induced cardiomyopathy (PICM).
• HBP is a viable alternative to RVP for preserving cardiac function in patients requiring ventricular pacing.