Abstract 14385: Safe Performance of Cardiac Magnet Resonance Imaging in Patients With a New Magnet Resonance Safe Pacemaker System
Background: The purpose of our study was to analyse potential alterations of electrical lead parameters in patients implanted with the EnRhythm MRI SureScan pacemaker system (MRI-PM; Medtronic Inc.) and who underwent cardiac magnet resonance imaging within the ESTIMATE MRT Study.
Methods: All patients implanted with the MRI-PM and who were enrolled in the ESTIMATE MRT study were included in this analysis. The purpose of this still ongoing prospective single center pilot study is to analyse potential changes in right and left ventricular functional parameters under permanent right ventricular stimulation at 80 and 110 bpm, using magnet resonance imaging [MRI] for analysis. During MRI examination at 1.5 Tesla the isocenter landmark was placed within the thorax. Lead measurements (atrial/ventricular sensing [mV], atrial/ventricular pacing threshold [Volt@0.4 ms], pacing impedance [Ohms@5V]) were assessed immediately before and after MRI, as well as 3 months after MRI. The study was approved by the local ethical committee. Statistical analyses were performed using one-way ANOVA and paired t-test for comparison of lead measurements. A p<0.05 was considered significant.
Results: By now 19 patients (age 65±14 years; female 7; indication for PM implantation: sick sinus syndrome 8, higher degree AV block 7, other 4) implanted with the MRI-PM underwent cardiac MRI within the ESTIMATE MRT study. Fifteen patients completed the 3 month follow-up (FU) after MRI by now. No device malfunctions were observed during and after MRI. One-way ANOVA revealed no significant differences in lead measurements between the 3 FUs. T-test revealed significant differences between the FU immediately before and after the MR scan for atrial pacing threshold (pre: 0.68±0.25; post: 0.56±0.17; p=0.041) and ventricular sensing (pre: 9.5±4.5; post: 10.3±4.5; p=0.02). When comparing lead measurements between the FU immediately before MRI and 3 months after MRI a statically significant differences could be found only for ventricular sensing (pre: 10.5±4.4; 3 months: 11.8±4.6; p=0.042).
Conclusions: The results of our study show stable lead measurements after cardiac MRI performed in patients with a new MRI safe dual chamber pacemaker system. No MRI related device malfunctions occurred.
- © 2010 by American Heart Association, Inc.