Ventricular Tachycardia Ablation

Combined with the magnetically enabled radiofrequency (RF) ablation catheters (NaviStar® RMT ThermoCool® and NaviStar® RMT, Biosense Webster, Inc., Diamond Bar, CA) and an advanced electroanatomic mapping system (CARTO RMT, Biosense Webster, Inc.), the MNS is a fully integrated solution for the ablation of VT and is the only remote system that is specifically indicated in the treatment of VT. The pliable nature of the magnetic catheter combined with the precision of computer-assisted navigation allows the physician to reach even the most inaccessible locations in the ventricles and to confidently address the thin tissue of the outflow tracts. This flexibility increases the efficiency of VT ablation by minimizing the occurrence of ventricular ectopy, thus potentially creating a better map to guide VT treatment. The magnetic catheter is equally capable of facilitating both transseptal and retrograde aortic approaches to the ventricles.

Effectiveness is not sacrificed when adopting the magnetic catheter for VT ablation. In fact, the constant contact of the catheter against the cardiac wall leads to the delivery of very effective lesions without the high forces that can lead to steam pops. An example of a magnetically delivered lesion in ventricular tissue is shown in the figure below. The functionality of the MNS allows operators to replicate the results of the best hands in the world (who may use multiple catheters and sheaths to get these results) with a single magnetic catheter.

Szili-Torok and his colleagues at the Erasmus Medical Center in Rotterdam (Eur Heart J, 2010) presented a series of 64 consecutive VT ablation patients that included both idiopathic and scar-related VT. When they compared the results between the patients treated with Stereotaxis VT (n = 37) to patients treated with conventional methods (n = 27), they found a statistically significant improvement in acute success, case time, and fluoroscopy time in the Stereotaxis VT group (see chart). They concluded that Stereotaxis offers "major advantages for VT ablation."

DiBiase and colleagues from the Texas Cardiac Arrhythmia Institute in Austin, Texas (Heart Rhythm, 2010) detailed the results of 110 consecutive magnetic VT ablations, including ischemic and non-ischemic patients, and compared them with a group of 92 patients who underwent conventional VT ablation by the same operator. The results in this study were excellent, as both treatment groups had a chronic (> 1 year) freedom from VT of more than 85%. The fluoroscopy time was significantly shorter in the MNS group (24 ± 12 minutes) than in the conventional group (35 ± 22 minutes, p = 0.033).

Prestigious researchers such as Hindricks and colleagues from the Leipzig Heart Center in Leipzig, Germany have reported a chronic freedom from VT of 70% in a series of 30 patients with VT storm, arguably one of the most challenging arrhythmias faced by today's EP (Arya, et al, PACE 2010). A report from a large, multicenter clinical trial of scar-related VT patients led by Dr. Neuzil from Na Holmoce Hospital in Prague demonstrated acute success of nearly 90% while using less than 1 minute of fluoroscopy for mapping (Heart Rhythm, 2010).

Investigators such as Kuck, et al in Hamburg, Germany and Szili-Torok, et al in Rotterdam, Netherlands have demonstrated 100% acute success in outflow tract arrhythmia patients with minimal fluoroscopy and extremely low incidence of mechanically-induced PVC's (Europace 2009, Neth Heart J 2009). The key to success is the extreme accuracy of Stereotaxis maps, as demonstrated by Saoudi and colleagues from Monaco who demonstrated that magnetic maps yielded more representative anatomy and more accurate voltage mapping than conventionally-created maps in 20 patients with suspected ARVD.