Cardiac Rhythm Management
Articles Articles 2011 May


John Day, MD, FHRS,


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John Day, Editor-in-Chief

Dear Readers,

I hope that everyone who attended the 2011 Heart Rhythm Society scientific sessions enjoyed their experiences in San Francisco. Future issues of Innovations in Cardiac Rhythm Management will explore notable developments from this year's conference, while illustrating how and why these advancements will directly influence our daily practice.

Within this month's Letter I would like to further examine an original manuscript that you will find featured within this month's “Innovative Collections” section, entitled “Remote Magnetic Navigation and Catheter Ablation of Ventricular Tachycardia: From Concept to Reality” by Dr. Adam Berman. This article provides an excellent overview of the technology and includes insight into the author's experiences with ventricular tachycardia ablation. Dr. Berman's extensive experience is very clear, as he has achieved excellent outcomes with RMT technology.

Specifically, I am very impressed with some of the highly practical suggestions that are provided on utilizing this technology. Remote Magnetic Navigation (RMN) has truly found a very useful role in the ablation of ventricular tachycardia, especially the outflow tract tachycardias.

So where are we at with the role of RMN in the daily practice of an Electrophysiologist? I will try to provide an overview of this technology based on our experience of using RMN for the last 3 years.

1. What is the role of this technology for VT, atrial fibrillation, and other types of ablations?

We especially like RMN for right ventricular outflow tract PVCs/VT as RMN allows for very discreet catheter movement as well as the ability to easily navigate back to previously identified areas of interest. For VT originating from within the left ventricle, especially when approached transseptally, RMN allows for the construction of very detailed 3D maps and the enhanced ability to create linear lesions. It also can allow for movement around anatomical structures such as the papillary muscles due to the flexibility of the catheter.

While we use RMN for a minority of our atrial fibrillation (AF) cases, RMN allows easy navigation within the left atrium and the creation of linear lesions that may be better than with a manual, stiffer catheter. One definite advantage of RMN in both AF and right ventricular outflow tract cases is with regards to safety and minimizing the risk of cardiac perforation. RMN should reduce the risk of cardiac perforation from mechanical pushing as well as the potential for steam pops. Of course, an additional benefit is that there is less radiation exposure to the operator and the operator can sit in a comfortable control room chair rather than wear lead in the Electrophysiology lab.

Aside from right ventricular outflow tract VT/PVC cases and AF cases, we like RMN technology for right anterior and right anterolateral accessory pathways. As right anterior and right anterolateral pathways can be broad with difficulties in achieving stable catheter contact when done by hand, RMN may offer a particular advantage.

2. What are the limitations of RMN technology?

The biggest limitation of RMN technology is the learning curve for physicians and lab staff. For the physician, the trick is to learn a new “hand-eye” skill and to understand how to get the catheter to go where you need it to go. For staff, there are many issues with patient positioning and utilizing the technology to work properly with all of the other equipment in the Electrophysiology lab. As with any new technology, cases become much smoother and efficient once the physician and lab staff are comfortable with its implementation. Clearly, the physician and Electrophysiology lab staff must be willing to commit to learning this technology through continued use to ensure proficiency. This upfront and ongoing time commitment can be difficult, particularly in high volume facilities.

Outside of the “learning curve” issues, other major limitations include the ability to only manipulate a single catheter (U.S. systems) and that the contact force generated by the RMN system may be inadequate for patients with thick tissue.

3. What improvements are needed with the next generation of RMN technology?

Outside of reducing the cost of implementing this technology for new centers, the most important improvement would be the ability to manipulate more than one catheter. The ability to increase contact force would also be extremely helpful, especially in patients with thick myocardium. Finally, incorporating a pressure sensor to the technology would allow a better understanding of the biophysics of lesion development with RMN technology.

I would like to thank all of the contributors for their insightful manuscripts this month. I'd also invite all readers to our complimentary web platform for the Journal, which may be accessed at