Matthias Gutberlet MD, PhD, Presenter: Nothing to Disclose

Matthias Grothoff MD, Abstract Co-Author: Nothing to Disclose

Charlotte Eitel, Abstract Co-Author: Nothing to Disclose

Christopher Piorkowski, Abstract Co-Author: Nothing to Disclose

Philipp Sommer, Abstract Co-Author: Nothing to Disclose

Gerhard Hindricks, Abstract Co-Author: Nothing to Disclose

Magnetic resonance imaging (MRI) guided electrophysiology (EP) studies facilitate visualization of three-dimensional anatomy with the respective underlying arrhythmia substrate, real-time visualization of functional informations and complications, as well as lesion visualization during ablation under elimination of radiation exposure. We present our first experience of a real-time MRI guided EP study demonstrating current possibilites and drawbacks.

Five patients (4 male, 1 female; mean age 64.4 years (±10.2)) with symptomatic arrhythmias, 3 with typical atrial flutter, presented for isthmus ablation, 1 for an electrophysiology study (EP) and 1 for slow pathway ablation in AV-NRT. The ablations were performed successfully. After the conventional procedure in the EP lab all five patients were transferred to a 1.5 T whole body MRI scanner (Intera, Philips, Best, The Netherlands) for an EP diagnostic procedure. Two MRI compatible steerable diagnostic/ablation catheters (VisionTM, Imricor Medical Systems, Burnsville, MN, USA) were inserted via the femoral sheaths and manipulated by an experienced electrophysiologist. Using a commercially available interactive real-time steady-state free precession MRI sequence (TR=3 ms, TE=1ms, flip angle=35°, slice thickness=10mm, frame rate=8 per second).

Using passive catheter tracking all catheters could be placed successfully in the right ventricle (Panel A, B; RAO view) and in the right atrium (Panel C, D; RAO view) confirmed by intracardiac electrograms (Panel E). Furthermore, simple programmed stimulation maneuvers were performed (Panel F, ventricular pacing). During and after the procedure no adverse effects were observed in all patients.

To our knowledge this is the first pilot study of real-time MRI guided placement of multiple catheters in humans with subsequent performance of stimulation maneuvers. Challenges arise from delineation of precise surface ECG recordings in the MRI setting along with intracardiac electrograms, easier handling of catheters, visualization of catheters placed in the coronary sinus, facilitation of immediate defibrillation in the MRI setting and implementation of an active catheter tracking system.

MRI guided EP studies reduce radiation exposure to patient and staff and allows to control the results of atrial ablation procedures.

Gutberlet, M, Grothoff, M, Eitel, C, Piorkowski, C, Sommer, P, Hindricks, G, First Clinical Experience in Man with the IMRICOR-MR-EP System: Electrophysiology Study-guided by Real-Time MRI.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12036377.html