Advantage of optimizing V-V timing in cardiac resynchronization therapy devices

Area of Science:

• Cardiology
• Biomedical Engineering
• Medical Imaging

Background:

• Interventricular (V-V) timing optimization in cardiac resynchronization therapy (CRT) lacks consensus.
• Current CRT device timing optimization relies on various parameters.
• This study explores 3D ejection fraction (EF) and aortic velocity-time integral (VTI) for optimizing ventricular activation in CRT.

Purpose of the Study:

• To investigate the potential advantage of using 3D EF and aortic VTI to optimize ventricular activation in CRT devices.
• To assess global left ventricular (LV) function using these echocardiographic parameters.
• To determine if individualized V-V timing optimization improves CRT device function.

Main Methods:

• Seventy-four patients with adequate echocardiographic images were included.
• Aortic VTI and 3D EF were measured at five V-V settings.
• Data were analyzed using a two-tailed paired t-test to compare V-V timing settings.

Main Results:

• Comparing best to worst V-V timing, VTI improved by 4.7 cm (P < 0.0001) and 3D EF by 9.9% (P < 0.0001).
• VTI improved in 85% of patients and 3D EF in 72% with optimization.
• Only 26% of patients had the same optimal setting for both VTI and 3D EF.

Conclusions:

• Individualized echocardiographic V-V optimization of CRT devices improves global LV function, as measured by aortic VTI and 3D EF.
• Significant functional improvements were observed within an 80-ms V-V timing range.
• Optimization led to enhanced LV function in the majority of patients.