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.