A detailed view on pacemaker lead parameters remotely transmitted after magnetic resonance

BACKGROUND: The purpose of this study was to analyze potential influences of magnetic resonance (MR) on the course of automatically device-based assessed lead parameters remotely transmitted in patients who were implanted with MR-conditional permanent pacemakers (PMs) and who had nondiagnostic brain and lumbar spine MR (1.5T) within the ProMRI single center pilot study.

METHODS: The ProMRI study evaluated the feasibility of the Evia PMs with Safio S leads (Biotronik SE&Co KG, Berlin, Germany) in the MR environment. All patients were equipped with remote monitoring on the day of MR. Atrial (RA) und ventricular (RV) lead parameters (sensing, pacing capture threshold [PCT], pacing impedance) were automatically assessed and remotely transmitted on a daily or event-triggered basis for 3 months post MR. Remotely transmitted data were normalized for potential differences between at-daytime (in-office) and at-night-time (remotely) assessed parameters using the 1-month follow-up data for each patient. Confidence intervals of continuous data were calculated day-wise with one sample t-tests of post-MR/pre-MR differences, respectively.

RESULTS: A total of 2,428 data sets (mean 80 ± 20 per patient) were transmitted. Mean values for the different lead parameters were (RA/RV) 3.3 ± 2.0/14.4 ± 6.9 mV for sensing, 0.65 ± 0.17/0.78 ± 0.23 V/0.4 ms for PCT, and 516 ± 60/607 ± 47 Ω for pacing impedance. No significant differences were found compared with pre-MR measurements. No atrial PCT increases ≥0.5 V compared with pre-MR were observed, and in only one patient the ventricular PCT increased by ≥0.5 V from day 76 post-MR, presumably based on new antiarrhythmic therapy with amiodarone.

CONCLUSION: Our analyses of automatically assessed and remotely transmitted PM lead parameters after MR show that sensing amplitudes, PCTs, and pacing impedances are not affected in a clinically relevant way by MR.