Reduction of fluoroscopy time and dose
The success rate of ablation of AP was more than 90% and the incidence of complication was relatively low10-11. Therefore, catheter ablation of APs was standard therapeutic strategy for symptomatic AP patients1,12. However, the ablation needs the use of fluoroscopy and are associated with the radiation exposure for patients and medical staff. The long term risk of cancer from this medical radiation exposure was reported to be linear relation without no threshold. The higher dose of radiation exposure increases the risk of cancer. “ALARA- as low as reasonably achievable” is the principle for fluoroscopically guided invasive cardiovascular procedure13. The use of 3D mapping can reduce the irradiation time and its dose14-17. Furthermore, CARTO UNIVU system, which integrate the fluoroscopic images with the 3D map, can also reduce the radiation exposure for ablation of APs14. Our study also revealed that the dual chamber map can reduce the radiation exposure, compared with the single chamber map. With the single chamber map, fluoroscopic image is needed before the energy application to confirm the position of AV annulus. However, the dual chamber map can be useful to the detail connection of APs between atrium and ventricle. Once the map was created, the radiation wasn’t necessarily needed before the energy application. As a result, the radiation exposure was lower in the dual chamber map group.
SVT with APs are often found in young patients and the influence of radiation exposure was hazardous especially in younger patients. The safety and accuracy of the Rhythmia system for pediatric patients was previously unknown, but we reported that the Rhythmia system was safe and accurate in pediatric population. Our study included 28 patients whose age were less than twenty and the minimum age was 3 years-old. The dual chamber map would be useful for patients of various generations.
The radiation time and dose in both groups were relatively higher than that of the previous study14,15. The fluoroscopic time in the study of CARTO UNIVU was only 0.1min14. The securing of vascular access, the insertion of EP catheter, and the trans septal puncture in our study was performed under the fluoroscopic guide. This could be result in the higher fluoroscopic time and dose than that of the previous study.