Dynamic programming of atrioventricular delay improves electrical synchrony in a multicenter cardiac...

Area of Science:

• Cardiology
• Biomedical Engineering

Background:

• Patient-specific programming for cardiac resynchronization therapy (CRT) is crucial due to high nonresponse rates.
• The SyncAV algorithm dynamically adjusts atrioventricular delays for individual patient needs.

Purpose of the Study:

• To evaluate the acute effect of biventricular (BiV) pacing with the SyncAV algorithm on electrical synchrony.
• To assess SyncAV's impact across a broad patient population with existing CRT implants.

Main Methods:

• Prospective evaluation of 90 patients with CRT implants at 5 international centers.
• Blinded 12-lead electrocardiographic QRS duration (QRSd) measurements compared intrinsic conduction, BiV pacing, and BiV + SyncAV (default and optimized offsets).
• BiV configurations were tested using both latest and earliest activating left ventricular (LV) electrodes.

Main Results:

• SyncAV with an optimized offset achieved maximal QRSd reduction (20% ± 10%) compared to traditional BiV pacing (9% ± 20%) and default SyncAV (13% ± 14%).
• Intrinsic QRS duration was the sole significant predictor of QRSd reduction magnitude.
• Similar QRSd reductions were observed regardless of the LV pacing electrode used.

Conclusions:

• SyncAV enhances acute electrical synchrony beyond conventional CRT, especially with patient-specific optimization.
• The degree of synchrony improvement is dependent on intrinsic QRSd.
• SyncAV's effectiveness is not limited by other baseline characteristics or the specific LV pacing electrode.