Magnetic resonance imaging at 1.5 Tesla produced temperature increases of up to 20 degrees C at the pacemaker lead tip in an animal model, causing significant impedance changes.
AIMS: Magnetic resonance imaging (MRI) is well established as an important diagnostic tool in medicine. However, the presence of a cardiac pacemaker is usually regarded as a contraindication for MRI due to safety reasons. In this study, heating effects at the myocardium-pacemaker lead tip interface have been investigated in a chronic animal model during MRI at 1.5 Tesla. METHODS AND RESULTS: Pacemaker leads with additional thermocouple wires as temperature sensors were implanted in nine animals. Temperature increases of up to 20 degrees C were measured during MRI of the heart. Significant impedance and minor stimulation threshold changes could be seen. However, pathology and histology could not clearly demonstrate heat-induced damage. CONCLUSIONS: MRI may produce considerable heating at the lead tip. Changes of pacing parameters due to MRI could be seen in chronic experiments. Potential risk of tissue damage cannot be excluded even though no reproducible alterations at the histological level could be found.
Luechinger et al. (Mon,) conducted a other in Presence of a cardiac pacemaker (n=9). Magnetic resonance imaging (MRI) was evaluated on Temperature increase at the myocardium-pacemaker lead tip interface. Magnetic resonance imaging at 1.5 Tesla produced temperature increases of up to 20 degrees C at the pacemaker lead tip in an animal model, causing significant impedance changes.