Late deterioration of left ventricular function after right ventricular pacemaker implantation

Area of Science:

• Cardiology
• Electrophysiology
• Heart Failure Management

Background:

• Right ventricular (RV) pacing can induce left bundle branch block patterns and lead to heart failure.
• Patients with dual chamber pacemakers (DCPs) experiencing reduced left ventricular ejection fraction (LVEF) due to high RV pacing are potential candidates for cardiac resynchronization therapy (CRT).

Purpose of the Study:

• To evaluate the efficacy of upgrading DCPs to CRT by adding a left ventricular (LV) lead in improving LV function in patients with reduced LVEF post-DCP implantation.

Main Methods:

• Retrospective analysis of 22 patients with DCPs and >90% RV pacing, presenting with new-onset heart failure and reduced LVEF.
• Exclusion of other causes for reduced LVEF via echocardiography and coronary angiography.
• Upgrade of DCPs to biventricular devices, followed by assessment of LVEF, QRS duration, and NT-pro BNP levels.

Main Results:

• LVEF declined from 54±10% to 31±7% with DCPs; QRS duration was 161±20 ms; NT-pro BNP levels were elevated.
• After upgrading to CRT, biventricular pacing achieved 98.1±2%.
• Significant improvements observed: QRS duration decreased to 108±16 ms (1 month) and 106±20 ms (6 months). LVEF increased to 38±8% (1 month) and 41±11% (6 months). NT-pro BNP levels decreased to 3088±2326 pmol/L (1 month) and 1860±1838 pmol/L (6 months).

Conclusions:

• Upgrading from DCP to CRT is a beneficial strategy for patients experiencing heart failure secondary to high RV pacing.
• This intervention can effectively improve cardiac function and reduce heart failure markers in this specific patient population.