磁导航遥控射频导管消融治疗房室结折返性心动过速的初步体会

Objective To evaluate the safety and feasibility of remote radiofrequency catheter ablation of atrioventricular nodal reciprocating tachycardia (AVNRT) using the magnetic navigation system (MNS). Methods A total of 37 patients[female 29, mean age (44 ± 15 )years]with documented AVNRT were enrolled in this study from March 2007 to June 2009. A 4 mm tip magnetic mapping and ablation catheter ( Helios Ⅱ ,Stereotaxis, USA),which was remotely controlled by the MNS (Niobe Ⅱ , Stereotaxis, USA), was used for both mapping and ablation. Conventional slow pathway modification with focal ablation at the fight posterior septum was first performed in all patients. If it was failed, linear lesions at the base of Koch' s triangle was then done. Results After ablation, AVNRT was non-inducible in all 37 patients without any complication except one case experienced transient first degree AV block. Focal ablation was performed in 34 patients, and linear ablation strategy was used in the remaining three cases to achieve the end point. Among all the 37 patients, slow pathway ablation was achieved in 14, whereas slow pathway modification was reached in the remaining 23 cases.The mean procedural time, the RF deliveries, the duration of RF application were ( 120 ± 32) min, (2. 9 ± 1.6)times, ( 130 ± 33 )s,respectively. The total fluoroscopy time and the physician X-ray exposure time were(5.3 ±2. 7)min and(2.9 ± 1.1 ) min,respectively. There was no significant change of the AH interval,the HV interval,and the atrioventricular nodal conduction refractory period after ablation. Compared with the first 18 patients, the mean procedural time, the total fluoroscopy time and the X-ray fluoroscopy time during magnetic navigation were significantly decreased in the later 19 patients (P ＜0. 001 ). It indicated that the learning curve of remote catheter ablation using the MNS is short. Conclusion Remote catheter ablation using the MNS to cure AVNRT is safe and effective with short learning curve and decreasing X-ray exposure time for interventional physicians.

Ablation of atrioventricular nodal reciprocating tachycardia using remote magnetic navigation system