Acute changes in electromechanical parameters during different pacing configurations using a quadripolar left...

Area of Science:

• Cardiology
• Electrophysiology
• Medical Devices

Background:

• Quadripolar left ventricular (LV) leads offer multiple pacing configurations for cardiac resynchronization therapy (CRT).
• The impact of varying pacing configurations on LV dyssynchrony and systolic function remains incompletely understood.

Purpose of the Study:

• To evaluate the acute effects of different pacing vectors on LV electromechanical parameters in patients with quadripolar LV leads.
• To determine if specific pacing configurations can optimize LV dyssynchrony and contractile function.

Main Methods:

• A two-center study involving 21 CRT patients (mean age 65 ± 8 years) implanted with a quadripolar LV lead.
• Assessment included LV capture thresholds, electrogram optimization, and echocardiography across four pacing configurations (D1-P4, P4-RV coil, D1-RV coil, P4-M2).
• LV dyssynchrony and global longitudinal strain (GLS) were measured to assess contractile function.

Main Results:

• LV capture thresholds varied significantly across configurations, with higher values for P4-RV coil and P4-M2.
• Septal-to-lateral delay, a measure of dyssynchrony, decreased with D1-P4 and D1-RV coil pacing.
• Global longitudinal strain (GLS) significantly improved only with D1-P4 pacing, accompanied by increased stroke volume and reduced mitral regurgitation.

Conclusions:

• Changing pacing vectors in quadripolar LV leads leads to significant variations in electromechanical parameters.
• Individualized selection of the optimal pacing site can enhance the acute hemodynamic response to CRT.