The Boston Pace Study

Overview

Right ventricular (RV) pacing can cause left ventricular systolic dysfunction in 10- 20% of patients. Biventricular pacing had previously been shown to prevent left ventricular systolic dysfunction. However, implantation of coronary sinus lead increases procedural risk and can be limited by higher threshold and phrenic nerve capture. HIS pacing has been evaluated as an alternative pacing strategy, but its routine use was limited by difficulty of the procedure, success rate and high pacing threshold.

Left bundle branch area pacing (LBBAP) is a promising physiologic pacing technique that has been proposed as a pacing strategy to prevent pacing induced cardiomyopathy and for treatment of desynchrony in heart failure. LBBAP has been adopted widely and performed routinely on patients with AV block. Currently, it is up to the discretion of the proceduralist whether LBBAP is performed given that there is lack of evidence to guide pacing strategies.

Description

This pilot trial is a feasibility study that will assess for efficacy, safety and success rate of left bundle branch area pacing. The study will also examine the recruitment rate at 2 major tertiary hospitals.

The study will examine if the use of LBBAP can prevent the occurrence of pacing induced cardiomyopathy (PICM) compared to RV pacing among patients with normal left ventricular function and high-grade AV block.

The investigators hypothesize that the rate of pacing induced cardiomyopathy is lower with LBBAP compared to RV pacing in patients with normal left ventricular function requiring high burden of RV pacing.

Eligibility

Inclusion Criteria:

1. Age >18
2. Patients with complete AV block, high-grade AV block with an anticipated ventricular pacing rate of more than 40%
3. Left ventricular ejection fraction of 50% or more.
4. Echocardiogram within the last 3 months

Exclusion Criteria:

1. History of systolic dysfunction with LV EF of less than 50%
2. Prior myocardial infarction
3. Obstructive coronary artery disease
4. Severe valvular dysfunction
5. Life expectancy of less than a year
6. Pregnancy