Optimized biventricular pacing in atrioventricular block after cardiac surgery

Area of Science:

• Cardiology
• Cardiac Electrophysiology
• Postoperative Care

Background:

• Temporary pacing is crucial for managing heart block following open-heart surgery.
• Optimizing atrioventricular delay and ventricular pacing site can enhance cardiac output.
• This study investigated the potential for a 10% cardiac output improvement through optimized pacing.

Purpose of the Study:

• To evaluate the efficacy of optimizing atrioventricular delay and ventricular pacing site.
• To determine if biventricular pacing improves cardiac output in patients with postoperative heart block.
• To compare optimized pacing with standard pacing protocols.

Main Methods:

• Seven patients with heart block post-valve replacement underwent temporary pacing with wires in the right atrium, right ventricle, and left ventricle.
• Cardiac output was measured using an ultrasonic aortic flow probe.
• Atrioventricular delays were optimized, followed by testing different ventricular pacing sites.

Main Results:

• Biventricular pacing increased cardiac index by a mean of 22% over right ventricular pacing (p=0.0012) and 14% over left ventricular pacing (p=0.0133).
• Optimized pacing resulted in a 10% mean increase in cardiac index over standard pacing (p=0.009).
• A 17% increase in cardiac index was observed at end-expiratory beats with optimized pacing (p=0.011).

Conclusions:

• Biventricular pacing, when combined with optimized atrioventricular delay, effectively enhances cardiac output.
• This optimized pacing strategy provides a significant improvement of at least 10% in cardiac output compared to standard pacing.
• Biventricular pacing is a valuable approach for managing cardiac output in patients with postoperative heart block.