Cardiac resynchronization therapy optimization in nonresponders and incomplete responders using electrical...

Area of Science:

• Cardiology
• Biomedical Engineering

Background:

• Approximately 30%-50% of patients do not respond to cardiac resynchronization therapy (CRT).
• Current clinical strategies for optimizing CRT in non-responders are not well-established.

Purpose of the Study:

• To assess the impact of CRT optimization via electrical dyssynchrony mapping.
• To evaluate improvements in left ventricular (LV) function, size, and electrical dyssynchrony in non-responders.

Main Methods:

• Studied 39 patients with LV ejection fraction ≤40% and significant electrical dyssynchrony post-CRT.
• Measured electrical dyssynchrony using QRS area under the curve and defined a cardiac resynchronization index (CRI).
• Programmed optimal device settings based on electrical dyssynchrony maps and assessed outcomes via echocardiography.

Main Results:

• CRT optimization increased CRI from 49.4% to 90.8%.
• Significant improvements were observed in LV ejection fraction (31.8% to 36.3%) and LV end-systolic volume (108.5 to 98.0 mL).
• Mechanical dyssynchrony measures, including LV strain and aortic to pulmonic valve opening time, showed significant improvement.

Conclusions:

• CRT optimization using electrical dyssynchrony mapping effectively improves LV systolic function and mechanical dyssynchrony.
• This novel mapping technology provides a practical, noninvasive method for managing CRT non-responders and incomplete responders.