Bifocal Right Ventricular Pacing: Alternative to Biventricular Pacing for Cardiac Resynchronization Therapy?

Abstract

A 59-year-old patient with dilated cardiomyopathy, severe systolic left ventricular dysfunction and drug-refractory advanced heart failure (New York Heart Association-NYHA class III-IV symptoms) and prior history of mitral valve replacement was scheduled for implantation of a biventricular pacing system (cardiac resynchronization therapy-defibrillator or CRT-D device). The coronary sinus was cannulated after some effort and a venous coronary angiogram was performed. Although a posterolateral cardiac venous branch was identified to accommodate the left ventricular pacing lead, placement of the lead in this tributary was accompanied by phrenic nerve stimulation, which could not be remedied by moving to more proximal positions where the lead could not be stabilized. Having no other option except for sending the patient to surgery for epicardial lead placement, albeit most difficult and high-risk procedure due to prior history of cardiac surgery, we attempted bifocal right ventricular pacing by placing the composite pacing-defibrillating lead at a low septal position and the left ventricular lead at a very high right ventricular (RV) outflow tract position. The procedure was otherwise uncomplicated and the patient’s post-procedural course remained uneventful. The patient had a good clinical response to this type of bifocal RV pacing over the subsequent days and months with amelioration of his dyspneic symptoms and improvement of his quality of life. At the three-year follow-up he remains in NYHA class II category.