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

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.

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.

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.

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.