Upgrading to biventricular pacing guided by pressure-volume loop analysis during implantation

Area of Science:

• Cardiology
• Electrophysiology
• Heart Failure Management

Background:

• Chronic right ventricular (RV) pacing can negatively impact cardiac function.
• Cardiac resynchronization therapy (CRT) may improve outcomes in these patients.
• Optimal left ventricular (LV) lead placement is crucial for CRT success.

Purpose of the Study:

• To evaluate the clinical and echocardiographic response to CRT in patients with prior chronic RV pacing.
• To determine the optimal LV lead position using pressure-volume loop analysis during implantation.

Main Methods:

• A single-blinded, randomized, controlled crossover study involving 40 patients with chronic RV pacing and heart failure symptoms.
• Pressure-volume loop analysis (conductance catheter) to assess stroke work, LVEF, cardiac output, and LV dP/dt(max) during implantation.
• Comparison of 3-month periods of RV pacing versus CRT at optimal LV lead position.

Main Results:

• CRT at the optimal LV lead position significantly increased stroke work (37%), LVEF (16%), cardiac output (29%), and LV dP/dt(max) (11%) compared to baseline.
• Pressure-volume loop guided LV lead placement further enhanced benefits.
• RV outflow tract pacing showed no hemodynamic improvement.
• Follow-up showed improved symptoms, increased VO(2,max) (10%), and better LVEF, LV volumes, and mitral regurgitation with CRT.

Conclusions:

• CRT significantly improves LV function and clinical outcomes in patients with chronic RV pacing.
• Pressure-volume loop analysis during implantation aids in selecting the optimal LV pacing site for CRT.