Rapid right ventricular pacing with MR-compatible pacemaker lead for MR-guided aortic balloon valvuloplasty in swine.

Abstract

To assess the feasibility and effectiveness of rapid right ventricular pacing with a magnetic resonance (MR)-compatible pacemaker lead during MR-guided aortic valvuloplasty. This study was approved by the institutional animal research committee. Seven pigs were investigated. All experiments were performed with an interventional 1.5-T MR system. Interventions were monitored with a steady-state free precession real-time imaging sequence. An MR-compatible pacemaker lead was placed in the right ventricular apex with MR guidance before valvuloplasty. After positioning the balloon in valve position, valvuloplasty was performed with rapid right ventricular rapid pacing at a heart rate of 180 beats per minute to minimize cardiac output. Positioning of the pacemaker lead with MR guidance was feasible in all swine (sensing, 6 mV +/- 1; threshold, 1 V +/- 0.5). The lead could be seen on steady-state free precession images without inducing any artifacts. Rapid right ventricular pacing was feasible in all swine, and balloon stability at the time of inflation was achieved with no balloon movement. Aortic valvuloplasty was successfully accomplished in all experiments. Rapid right ventricular pacing with an MR-compatible pacemaker lead is feasible and effective.