Sensor-based electromagnetic tracking system may help to reduce radiation exposure in CRT implantation


A new technology that uses a sensor-based electromagnetic tracking system may help to guide cardiac resynchronisation therapy (CRT) device implantation safely and potentially cut radiation exposure time as compared with traditional fluoroscopy.

The first human use of the MediGuide (MGT, St Jude Medical) was published on 3 September in Circulation: Arrhythmia and Electrophysiology.

Sergio Richter, Department of Electrophysiology, Heart Center, University of Leipzig, Leipzig, Germany, and colleagues reported: “Cardiac resynchronisation therapy device implantation can be challenging, time consuming, and fluoroscopy intense. To facilitate left ventricular lead placement, a novel-sensor based electromagnetic tracking system has been developed.” In this study, Richter et al set out to evaluate the feasibility, safety, and performance of the MediGuide tracking system.

“For the first time the novel electromagnetic tracking system incorporates various aspects of organ mobility into technical solutions of catheter-tip localisation. It is the only technology at present allowing 3D catheter tracking in real time, without influence from primary or secondary organ motion. Therefore, after appropriate image acquisition, catheter tracking can be performed in dynamic images of the target cardiac anatomy without live fluoroscopy,” Richter et al reported.

To assess the technology, a prospective observational feasibility study (FHU study) was conducted at the Leipzig University Heart Center between January and February 2012. The new tracking system was used in 15 heart failure patients (8 men and 7 women, average age 66±8 years) to place the left ventricular lead via the coronary sinus on the left ventricle. Traditional fluoroscopy-guided implantation was used for the two device leads on the right side of the heart.

Study patients were initially followed for four weeks after implantation. According to the authors, the CRT system was successfully implanted with a lateral or posterolateral left ventricular lead position in all patients. The median fluoroscopy time (skin to skin) was 5.2 minutes on average and the median fluoroscopy time for left ventricular lead implantation was 2.6 minutes. “In comparison to published data, we observed a substantial reduction in fluoroscopy time and radiation exposure,” Richter et al wrote. Moreover, there were no severe complications that required an acute intervention or re-operation during the peri- and postoperative period.

The authors concluded that the implementation of this new technology during CRT implantation is safe and feasible. “The concept of sensor-based tracking of lead delivery tools within moving cardiac chambers has the potential to reduce radiation exposure with similar procedural outcome,” they wrote. However, future randomised studies are needed to confirm these findings, Richter et al reported.

The study was supported by a research grant from St Jude Medical.