A novel algorithm increases the delivery of effective cardiac resynchronization therapy during atrial fibrillation:
Christopher J Plummer1, Christopher M Frank2, Zsolt Bári3
1Freeman Hospital, Newcastle upon Tyne, United Kingdom.
Insights
A new algorithm, eCRTAF, significantly improves effective cardiac resynchronization therapy (CRT) delivery in patients with atrial fibrillation (AF). This novel approach enhances ventricular pacing percentage, potentially optimizing CRT benefits for these patients.
Area of Science:
- Cardiology
- Biomedical Engineering
- Medical Devices
Background:
- Cardiac resynchronization therapy (CRT) efficacy depends on high ventricular pacing percentage (%Vp).
- Atrial fibrillation (AF) can decrease %Vp in CRT due to irregular intrinsic atrioventricular conduction.
- Optimizing CRT during AF is crucial for maximizing patient benefits.
Purpose of the Study:
- To evaluate a novel algorithm, eCRTAF, for improving effective CRT delivery during AF.
- To compare eCRTAF against a standard rate regularization algorithm in AF patients.
Main Methods:
- Prospective randomized crossover trial involving CRT-defibrillator patients with AF.
- Patients received both control and eCRTAF algorithms for 4 weeks each in a randomized sequence.
- Key metrics recorded included percent effective CRT (%eCRT), %Vp, and mean heart rate (HR) during AF.
Main Results:
- eCRTAF significantly increased %eCRT during AF compared to control (87.8% vs 80.8%, P < .001).
- eCRTAF also significantly increased %Vp during AF versus control (90.0% vs 83.2%, P < .001).
- A small but significant increase in mean HR was observed with eCRTAF (79.5 bpm vs 77.0 bpm, P < .001).
Conclusions:
- The eCRTAF algorithm effectively increases %eCRT and %Vp in CRT patients with AF.
- This novel algorithm offers a potential noninvasive method to enhance CRT effectiveness.
- Improved CRT delivery during AF may lead to better clinical outcomes and CRT response.
Background:
Cardiac resynchronization therapy (CRT) requires a high percentage of ventricular pacing (%Vp) to maximize its clinical benefits. Atrial fibrillation (AF) has been shown to reduce %Vp in CRT due to competition with irregular intrinsic atrioventricular (AV) conduction. We report the results of a prospective randomized crossover trial evaluating the amount of effective CRT delivered during AF with a novel algorithm (eCRTAF).
Objective:
The purpose of this study was to determine whether eCRTAF increases the amount of effective CRT delivered during AF compared to a currently available rate regularization algorithm.
Methods:
Patients previously implanted with a cardiac resynchronization therapy-defibrillator and with a history of AF and intact AV conduction received up to 4 weeks of control (Conducted AF Response) and up to 4 weeks of eCRTAF in a randomized sequence. The percent effective CRT (%eCRT) pacing, which excludes beats without left ventricular capture, %Vp, and mean heart rate (HR) were recorded during AF and sinus rhythm.
Results:
The eCRTAF algorithm resulted in a significantly higher %eCRT during AF than control (87.8% ± 7.8% vs 80.8% ± 14.3%; P <.001) and %Vp during AF than control (90.0% ± 5.9% vs 83.2% ± 11.9%; P <.001), with a small but statistically significant increase in mean HR of 2.5 bpm (79.5 ± 9.7 bpm vs 77.0 ± 9.9 bpm; P <.001).
Conclusion:
In a cohort of CRT patients with a history of AF, eCRTAF significantly increased %eCRT pacing and %Vp during AF with a small increase in mean HR. This algorithm may represent a novel noninvasive method of significantly increasing effective CRT delivery during AF, potentially improving CRT response.
