An electrographic AV optimization for the maximum integrative atrioventricular and ventricular resynchronization in...

Area of Science:

• Cardiology
• Biomedical Engineering
• Electrophysiology

Background:

• Atrioventricular (AV) delay significantly impacts AV and ventricular synchrony in cardiac resynchronization therapy (CRT).
• Optimizing AV delay for optimal AV synchrony (AVopt-AV) or ventricular synchrony (AVopt-V) can lead to conflicting settings.
• Discordance in optimization strategies necessitates a unified approach for maximum CRT benefit.

Purpose of the Study:

• To explore a novel AV delay optimization algorithm guided by electrograms.
• To achieve maximum integrative effects of both AV and ventricular resynchronization (opt-AV).
• To develop a method for determining the ideal AV delay in CRT patients.

Main Methods:

• Enrolled 49 patients undergoing CRT.
• Measured AVopt-AV using the Ritter method and AVopt-V by achieving the narrowest QRS duration.
• Defined opt-AV as AVopt-AV or AVopt-V if the difference was <20 ms, or the AV delay yielding maximal aortic velocity-time integral if the difference was >20 ms.

Main Results:

• Sensing/pacing AVopt-AV (SAVopt-AV/PAVopt-AV) correlated with atrial activation time (P<0.05).
• Sensing/pacing AVopt-V (SAVopt-V/PAVopt-V) correlated with intrinsic AV conduction time (P<0.01).
• A significant proportion of patients (62.9% sensing, 57.1% pacing) showed >20 ms differences between AVopt-AV and AVopt-V; opt-AV correlated linearly with both, leading to derived predictive equations.

Conclusions:

• SAVopt-AV/PAVopt-AV and SAVopt-V/PAVopt-V are linked to atrial activation and intrinsic AV conduction times, respectively.
• A substantial percentage of patients exhibit >20 ms discrepancies between AV synchrony and ventricular synchrony optimization.
• The study successfully estimated optimal AV delay (opt-AV) using electrogram parameters, offering a potential improvement for CRT programming.