Zero-fluoroscopy approach for ablation of supraventricular tachycardia using the Ensite NavX system: a multicenter experience

Abstract

Background: Three-dimensional electroanatomic mapping systems have demonstrated a significant reduction in radiation exposure during radiofrequency catheter ablation procedures. We aimed to investigate the safety, feasibility and efficacy of a completely zero-fluoroscopy approach for catheter ablation of supraventricular tachycardia using the Ensite NavX navigation system compared with a conventional fluoroscopy approach.

Methods: A multicenter prospective non-randomized registry study was performed in seven centers from January 2013 to February 2018. Consecutive patients referred for catheter ablation of supraventricular tachycardia were assigned either to a completely zero-fluoroscopic approach (ZF) or conventional fluoroscopy approach (CF) according to the operator's preference. Patients with atrial tachycardia were excluded.

Results: Totally, 1020 patients were enrolled in ZF group; 2040 patients ablated by CF approach were selected for controls. There was no significant difference between the zero-fluoroscopy group and conventional fluoroscopy group as to procedure time (60.3 ± 20.3 vs. 59.7 ± 22.6 min, P = 0.90), immediate success rate of procedure (98.8% vs. 99.2%, P = 0.22), arrhythmia recurrence (0.4% vs. 0.5%, P = 0.85), total success rate of procedure (98.4% vs. 98.8%, P = 0.39) or complications (1.1% vs. 1.5%, P = 0.41). Compared with the conventional fluoroscopy approach, the zero-fluoroscopy approach provided similar outcomes without compromising the safety or efficacy of the procedure.

Conclusion: The completely zero-fluoroscopy approach demonstrated safety and efficacy comparable to a conventional fluoroscopy approach for catheter ablation of supraventricular tachycardia, and mitigated radiation exposure to both patients and operators.

Trial registration: clinicaltrials.gov Identifier: NCT03042078; first registered February 3, 2017; retrospectively registered.

Keywords: Radiation exposure; Radiofrequency ablation; Supraventricular tachycardia; Zero-fluoroscopy.

Conflict of interest statement

The authors declare that they have no competing interests.

Figures

Fig. 1

A J-shaped wire was placed into a subclavian vein. A correct insertion was verified by the characteristic interference signal, which was produced by rotating the J-shaped wire when the first catheter had been positioned at the middle of right atrium. The white arrows indicate the vertical magenta line associated with the interference signal. Abbreviations: LAO, left anterior oblique view; RAO, right anterior oblique view

Fig. 2

Stepwise approach to placement of the steerable-curve electrode into a coronary sinus via the femoral vein. Generally, a fixed-curve quadripolar electrode was placed into the apex of right ventricle (as shown in blue bands); then His potential was recorded by the electrode and marked by yellow dot. a First, the steerable electrode was advanced to the position about one centimeter below the position of his potential or peak of tricuspid valve. b Secondly, it was flexed toward the right ventricle. c Thirdly, it was rotated backward to locate the orifice of coronary sinus. d Fourthly, the electrode was extended gently. e Finally, the tip of electrode was advanced distally into coronary sinus. The solid arrow and blank arrow showed the track of catheter tip in RAO and LAO, respectively

Fig. 3

The virtual geometry of the targeted area in the right atrium was reconstructed during ablation of AVNRT. Upper panel: the ablation catheter was placed at the His bundle with the tip of the catheter shown in green, and the area of the His bundle is labeled with yellow dots, and the yellow and blue bands show the electrodes placed in the coronary sinus and in the right ventricle, respectively; typical slow pathway potential was mapped and marked with a blue dot and finally power delivery at 35 watts , which was marked as red dot, led to slow junctional beats. Lower panel: the white arrows show the His bundle electrogram recorded by the ablation catheter. AVNRT, atrioventricular nodal reentrant tachycardia; the abbreviations are as in Fig. 1

Fig. 4

A patient with two manifest right sided accessory pathways was ablated using the ZF approach. Upper panel showed that the tricuspid valve was labeled with white dots and the site of the His bundle was labeled with yellow dots in RAO and LAO. The ablation catheter was placed at the first accessory pathway at about nine o’clock during tachycardia. Left lower panel showed the electrogram recording at the first target site. Right lower panel showed the second accessory pathway at 5 o’clock marked with red dot. Other abbreviations are as in Fig. 1

Fig. 5

A concealed left accessory pathway was mapped and ablated using the ZF approach. The two white arrows in lower panel shows the endocardial electrogram recorded by the ablation catheter (green tip) placed in the targeted ablation area through aorta via retrograde access. The bottom of noncoronary aortic cusp was marked with a blue dot and His potential was marked with a yellow dot. The solid white arrow marks the small “A” wave during sinus rhythm. The dashed white arrow indicates the earliest “A” wave fused in the “V” wave during right ventricular pacing. Abbreviations are as in Fig. 1

Fig. 6

a The learning curve of the zero-fluoroscopy (ZF) approach during the ablation of supraventricular arrhythmia. Panel showed the average procedure time for the 1st to 20th cases, 21st to 40th cases, 41st to 60th cases, and all cases when each of the two approaches was used. b Graph showed linear trend of the procedure time for the first 120 ablations performed using zero-fluoroscopy approach