AV-optimized conduction system pacing for treatment of AV dromotropathy: A randomized, cross-over study

Area of Science:

• Cardiology
• Electrophysiology
• Medical Devices

Background:

• Severe first-degree atrioventricular (AV) block can mimic heart failure symptoms due to AV dyssynchrony (AV dromotropathy).
• Current guidelines suggest permanent pacemaker implantation for this condition, but supporting evidence is limited.

Purpose of the Study:

• To evaluate the effectiveness of AV-optimized conduction system pacing (CSP) in patients with symptomatic severe first-degree AV block and AV dyssynchrony.

Main Methods:

• A single-blind, cross-over study randomized 14 patients with symptomatic severe first-degree AV block to either AV-optimized CSP or backup VVI pacing.
• Patients underwent a 3-month period of each pacing strategy, with comparisons of exercise capacity, echocardiographic parameters, and symptom occurrence.

Main Results:

• AV-optimized CSP significantly increased exercise workload (p=0.032) and left ventricular stroke volume (LVSV, p<0.001) compared to backup pacing.
• A trend towards higher peak VO2 was observed (p=0.224).
• Patients reported symptomatic improvement, with 71% preferring AV-optimized CSP (p=0.008).

Conclusions:

• AV-optimized CSP demonstrates potential to enhance exercise capacity, improve left ventricular stroke volume, and alleviate symptoms in patients with severe first-degree AV block.