Novel Device-Based Algorithm Provides Optimal Hemodynamics During Exercise in Patients With Cardiac Resynchronization...

Area of Science:

• Cardiology
• Biomedical Engineering
• Medical Devices

Background:

• Adaptive cardiac resynchronization therapy (aCRT) offers synchronized left ventricular (LV) pacing and continuous optimization.
• Limited data exists on aCRT algorithm performance during patient exercise.

Purpose of the Study:

• To evaluate the efficacy of an aCRT algorithm in optimizing cardiac function during exercise.
• To compare aCRT performance against manual echo-optimization of atrioventricular (AV) and interventricular (VV) delays.

Main Methods:

• 27 patients with aCRT were enrolled and manually programmed at rest and during two exercise stages.
• Echocardiograms assessed cardiac output via LV outflow tract velocity time integral (LVOT-VTI).
• Compared cardiac output between manual optimization and aCRT-on during rest and exercise.

Main Results:

• Optimal AV delay shortened progressively with increased exercise levels (P<0.05).
• aCRT and manual optimization showed similar cardiac performance (LVOT-VTI concordance: Ex.1 r=0.94, Ex.2 r=0.88).
• Synchronized LV-only pacing yielded higher LVOT-VTI than conventional biventricular pacing at peak exercise (P<0.05).

Conclusions:

• The aCRT algorithm is physiologically sound and effective during patient exercise.
• aCRT provides a viable alternative for optimizing cardiac resynchronization therapy in dynamic conditions.