Download INNOVATIVE TECHNIQUES EXPERT COMMENTARY

The Journal of Innovations in Cardiac Rhythm Management, 3 (2012), 888–890
INNOVATIVE TECHNIQUES
EXPERT COMMENTARY
Novel Approach for Mapping of a Left-Sided Accessory Pathway Using
Remote Magnetic Catheter Navigation Technology
There are a growing number of invasive electrophysiologists who believe that the future will
bring improved patient outcomes, safety, and efficiency through the technology of robotics. One
of the leading robotic technologies is remote magnetic catheter navigation technology (RMT).
Recent medical literature contains a number of case reports and series demonstrating the
feasibility of this technology in many settings. These include mapping and ablation of
tachycardias in the setting of complex congenital heart disease,1,2 more routine supraventricular
tachycardias,3 and ventricular tachycardia.4–6 There has also been a small trial comparing
transseptal versus retrograde aortic approaches to left-sided accessory pathways using RMT.7
Beyond feasibility, we are of course concerned with the question of demonstrated improvement
over current technology. There is supporting literature for the use of RMT to reduce fluoroscopy
times for both the patient and the physician, while producing similar outcomes.8–12 As with mapping and ablation in
congenital heart disease, there is also demonstrated benefit in navigating difficult anatomy.13 Theoretical benefits, with less
supporting literature, include 1) more accurate cardiac geometry creation due to consistent catheter tip–tissue contact without
regional distortion from excess force;13–14 2) improvement in safety through atraumatic catheter movement and therefore
reduction in the risk of cardiac perforation; 3) improved ablation through more consistent catheter–tissue contact; and 4)
improved workflow through shortened and more consistent procedure times.
There are concerns that have been raised as well. These include 1) potential lack of catheter tip stability and therefore
reduced ablation efficacy due to limited tissue contact force; 2) the effect of the learning curve on practice processes;
and 3) increased cost of equipment. Each of these must be addressed as the technology becomes more widely utilized.
In this case report, the authors present an innovative use of RMT that allowed for the successful completion of a
difficult case in which the diagnosis was straightforward, but the patient’s anatomy was not. It highlights the unique
capabilities of the system in safely accessing challenging anatomy. It also highlights the innovative thinking required to
get the most from this new technology. In particular, the team addressed the concern that the floppy nature of the RMT
catheter, considered a positive attribute with regard to safety and accessing difficult anatomy, would limit catheter tip
stability along the mitral annulus. Their innovative approach, in which the catheter is prolapsed into the left atrium
from the left ventricle and then back to the mitral valve, is clearly effective in avoiding this difficulty.
The importance of highlighting this example lies in more than demonstrating a particular technique for a particular
case or situation. This case study represents one of the most important steps toward the adoption of new technology:
thinking ‘‘outside the box.’’ As new technology is adopted, we initially try to replicate what is being done with existing
tools. However, once the operator is familiar with the technology, the true innovation comes in the application of the
technology in new ways.
This point is brought home by a recent case in our lab in which RMT was used to successfully map and ablate a
patient suffering from frequent superior mitral annular premature ventricular contractions and non-sustained
ventricular tachycardia. As the fluoroscopic and three-dimensional electroanatomic images display (Figure 1), the
chosen approach was transseptal. The unique flexibility and navigation capabilities of the RMT system were used to
map from this approach not just the left ventricle and mitral annulus, but also the aortic root. This was accomplished
by prolapsing the catheter within the left ventricle and out the aortic valve, and then prolapsing once again within the
ascending aorta to direct the catheter tip back down to the aortic root.
Among the biggest challenges facing any emerging technology, beyond the simple question of ‘‘does it work,’’ is the
jump from use by a limited number of early adopters to more generalized use. The first step in this process is the
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The Journal of Innovations in Cardiac Rhythm Management, August 2012
Left-Sided Accessory Pathway Mapping
Figure 1: Three-dimensional electroanatomic image (a) and fluoroscopic image in LAO projection (b) demonstrating the map
created from a transseptal approach by prolapsing of the catheter within the left ventricle and out the aortic valve, and then
prolapsing once again within the ascending aorta to direct the catheter tip back down to the aortic roo.
demonstration that the technology is useable in everyday routine practice, and not just reserved for especially difficult
cases. Are the techniques employed in the cases presented here the only ways to care for these patients? Of course not:
we have been doing similar cases successfully for years. Nevertheless, they do demonstrate the versatility of this new
technology. In particular, they remind us that cases that might seem straightforward on the way into the lab may prove
to be more challenging than expected. Clearly, RMT is capable of providing good outcomes for our more routine work.
The availability of technical capabilities and techniques for handling more complex situations safely and effectively is
where RMT may shine in providing the best outcomes for our patients.
A second key to the broader adoption of RMT will be the publication of convincing evidence of good outcomes and
successful integration of the technology into practice processes. Although the above mentioned publications are a start,
randomized studies have yet to be performed and reported.
What we all hope for are innovations that will eventually lead to better outcomes through successful achievement of
procedural goals, improved safety, and gains in efficiency that justify the associated expense. Robotic technologies are in
the early stages of defining their role in current practice. They certainly hold much promise for our vision of the future.
J. Peter Weiss, MD, MSc
[email protected]
Intermountain Heart Institute
Intermountain Heart Rhythm Specialists
Salt Lake City, UT
References
1. Wu J, Pflaumer A, Deisenhofer I, Hoppmann P, Hess J, Hessling G. Mapping of atrial tachycardia by remote magnetic navigation
in postoperative patients with congenital heart disease. J Cardiovasc Electrophysiol 2010; 21:751–759.
2. Ernst S, Babu-Narayan SV, Keegan J, et al. Remote-controlled magnetic navigation and ablation with 3D image integration as an
alternative approach in patients with intra-atrial baffle anatomy. Circ Arrhythm Electrophysiol 2012; 5:131–139.
3. Xu D, Yang B, Shan Q, et al. Initial clinical experience of remote magnetic navigation system for catheter mapping and ablation of
supraventricular tachycardias. J Interv Card Electrophysiol 2009; 25:171–174.
4. Arya A, Eitel C, Bollmann A, et al. Catheter ablation of scar-related ventricular tachycardia in patients with electrical storm using
remote magnetic catheter navigation. Pacing Clin Electrophysiol 2010; 33:1312–1318.
5. Akca F, Önsesveren I, Jordaens L, Szili-Torok T. Safety and efficacy of the remote magnetic navigation for ablation of ventricular
tachycardias—a systematic review. J Interv Card Electrophysiol 2012; 34:65–71.
6. Dinov B, Schönbauer R, Wojdyla-Hordynska A, et al. Long-term efficacy of single procedure remote magnetic catheter
navigation for ablation of ischemic ventricular tachycardia: a retrospective study. J Cardiovasc Electrophysiol 2012; 23:499–505.
7. Schwagten B, Jordaens L, Rivero-Ayerza M, et al. A randomized comparison of transseptal and transaortic approaches for
magnetically guided ablation of left-sided accessory pathways. Pacing Clin Electrophysiol 2010; 33:1298–1303.
8. Kim JJ, Macicek SL, Decker JA, Kertesz NJ, Friedman RA, Cannon BC. Magnetic versus manual catheter navigation for ablation
of free wall accessory pathways in children. Circ Arrhythm Electrophysiol 2012 May 24. [Epub ahead of print].
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9. Lüthje L, Vollmann D, Seegers J, et al. Remote magnetic versus manual catheter navigation for circumferential pulmonary vein
ablation in patients with atrial fibrillation. Clin Res Cardiol 2011; 100:1003–1011.
10. Dinov B, Schönbauer R, Wojdyla-Hordynska A, et al. Long-term efficacy of single procedure remote magnetic catheter
navigation for ablation of ischemic ventricular tachycardia: a retrospective study. J Cardiovasc Electrophysiol 2012; 23:499–505.
11. Schmidt B, Tilz R, Neven K, Chun K, Fürnkranz A, Ouyang F. Remote robotic navigation and electroanatomical mapping for
ablation of atrial fibrillation. Circ Arrhythmia Electrophysiol 2009; 2:120–128.
12. Saliba W, Reddy VY, Wazni O, et al. Atrial fibrillation ablation using a robotic catheter remote control system: Initial human
experience and long-term follow-up results. J Am Coll Cardiol 2008; 51:2407–2411.
13. Miyazaki S, Nault I, Haı̈ssaguerre M, Hocini M. Atrial fibrillation ablation by aortic retrograde approach using a magnetic
navigation system. J Cardiovasc Electrophysiol 2010; 21:455–457.
14. Okumura Y, Johnson SB, Bunch TJ, Henz BD, O’Brien CJ, Packer DL. A systematical analysis of in vivo contact forces on virtual
catheter tip/tissue surface contact during cardiac mapping and intervention. J Cardiovasc Electrophysiol 2008; 19:632–640.
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