Rapid right ventricular pacing with mr-compatible pacemaker lead for magnetic resonance-guided aortic balloon valvuloplasty in swine

Methods 6 pigs (weight 48 ± 3 kg) were investigated. All experiments were performed using an interventional 1.5 Tesla MRI system. Interventions were monitored using a steadystate free precession real-time imaging sequence. Parameters of the sequence were TR/TE = 2.5/1.25 ms, flip angle 45°, slice thickness 8 mm, matrix 128 × 128 reconstructed to 256 × 256 using zero-filling. A MR-compatible pacemaker lead was placed in the right ventricular apex under fluoroscopic MR-guidance before the valvuloplasty. After positioning of the balloon into the left ventricular outflow tract/aortic valve valvuloplasty was performed under rapid right ventricular pacing at a heart rate of 180 bpm to minimize cardiac output. For improved visualization the balloon was filled with Resovist.