Comparison between biventricular pacing and single site pacing in patients with poor ventricular function: a...

Area of Science:

• Cardiology
• Electrophysiology
• Heart Failure Management

Background:

• Advanced heart failure and left bundle branch block often necessitate pacing for hemodynamic support.
• Biventricular pacing is theorized to provide superior hemodynamic benefits over single-site pacing in these patients.

Purpose of the Study:

• To investigate the acute hemodynamic effects of multisite ventricular pacing in patients with advanced heart failure and left bundle branch block.
• To compare the efficacy of right ventricular (RV), left ventricular (LV), and biventricular pacing on cardiac output (CO), pulmonary capillary wedge pressure (PCWP), and left ventricular pressure increase rate (LV + dP/dtmax).

Main Methods:

• Eighteen patients with advanced heart failure and left bundle branch block underwent acute, randomized, multisite ventricular pacing.
• Pacing occurred at RV, LV, and biventricular sites for 5 minutes each, with hemodynamic parameters measured.
• The best achieved measures of CO, PCWP, and LV + dP/dtmax were compared across pacing sites.

Main Results:

• Pacing improved CO in all patients, and LV + dP/dtmax and PCWP in 17 out of 18 patients.
• No significant group differences were observed in PCWP or CO between RV, LV, and biventricular pacing.
• Increases in stroke volume/PCWP and LV + dP/dtmax were not significantly greater with LV or biventricular pacing compared to RV pacing.

Conclusions:

• Ventricular pacing can provide hemodynamic benefits in heart failure patients with conduction delays.
• Significant individual variations exist in optimal pacing site for maximal hemodynamic improvement.
• On a group level, biventricular and LV pacing demonstrated only modest hemodynamic advantages over RV pacing.