Tissue synchronization imaging and optimal left ventricular pacing site in cardiac resynchronization therapy

Area of Science:

• Cardiology
• Cardiac Electrophysiology
• Echocardiography

Background:

• Optimal left ventricular (LV) pacing site for cardiac resynchronization therapy (CRT) remains debated.
• Tissue synchronization imaging (TSI) offers novel insights into myocardial delay patterns.

Purpose of the Study:

• To determine if LV lead positioning guided by maximal mechanical delay improves CRT outcomes.
• To assess the correlation between LV lead placement and reverse remodeling.

Main Methods:

• Echocardiography including TSI in 54 heart failure patients before and after CRT.
• Patients categorized into three groups based on LV lead proximity to maximal delay site.
• Response assessed by LV reverse remodeling and systolic function changes.

Main Results:

• Group 1 (pacing at maximal delay) showed significantly greater LV reverse remodeling (23% decrease in end-systolic volume) compared to adjacent (15%) and remote (8.9% increase) groups.
• 16/22 patients in Group 1 achieved reverse remodeling, versus 7/13 in Group 2 and 1/19 in Group 3.
• LV lead position proximal to maximal delay site correlated with reverse remodeling (r=0.449, p=0.001).

Conclusions:

• Pacing at the site of maximal mechanical delay is associated with improved reverse remodeling in CRT.
• Individually tailored LV lead positioning based on TSI may optimize CRT efficacy.
• Consideration of maximal delay site for LV lead placement is recommended for CRT procedures.