Reversible Biventricular Dysfunction Due to Right Ventricular Pacing in a Patient With Prior Cancer Treatment

We report the case of a 54-year-old woman with a history of breast cancer treated with chemotherapy, surgery, and thoracic radiotherapy in 2007, who developed pacing-induced cardiomyopathy (PICM) after right ventricular pacing.

The patient initially presented with symptomatic trifascicular block and underwent single-chamber pacemaker implantation due to bilateral subclavian vein stenosis, with atrial sensing (VDD mode). Eight months postimplantation, she presented with heart failure symptoms and new-onset biventricular systolic dysfunction. Ventricular pacing was 100% owing to complete atrioventricular block. Coronary angiography was unremarkable, and catheterization confirmed elevated filling pressures without pericardial constrictive physiology.

Given the patient's lack of candidacy for cardiac resynchronization therapy, medical treatment was optimized, leading to significant functional improvement and recovery of biventricular function within 6 months.

This case highlights the potential reversibility of pacing-induced cardiomyopathy with optimal medical therapy when cardiac resynchronization therapy is not feasible.