Pacing therapy for atrioventricular dromotropathy: a combined computational-experimental-clinical study

Area of Science:

• Cardiovascular Physiology
• Biomedical Engineering
• Clinical Electrophysiology

Background:

• Atrioventricular (AV)-coupling is crucial for optimal cardiac function.
• Heart failure (HF) and prolonged PR intervals can impair AV-coupling.
• Pacemaker therapy aims to restore cardiac synchrony and improve hemodynamics.

Purpose of the Study:

• To investigate the hemodynamic effects of restoring AV-coupling using pacemaker therapy.
• To elucidate the underlying mechanisms in normal and failing hearts.
• To compare biventricular (BiV) pacing with right ventricular (RV) pacing.

Main Methods:

• Combined computational modeling (CircAdapt), experimental studies in pigs, and a clinical study in 22 HF patients.
• Measurement of left ventricular (LV) pressure and volume in patients with prolonged PR intervals.
• Simulation of AV-coupling restoration via BiV and RV pacing.

Main Results:

• Restoring AV-coupling increased LV filling, mean arterial pressure, and cardiac output by 10-15% in normal hearts.
• BiV pacing in HF patients significantly increased LV stroke volume (34%) and stroke work (26%).
• RV pacing abrogated the benefits of AV-coupling restoration due to worsened ventricular dyssynchrony.

Conclusions:

• Restoration of AV-coupling via BiV pacing significantly improves hemodynamics in HF patients with prolonged AV conduction.
• BiV or physiological pacing, not RV pacing, is recommended for improving cardiac function in these patients.
• Enhanced LV filling and reduced diastolic mitral regurgitation contribute to improved pump function.