Evaluation of a new very low dose imaging protocol: feasibility and impact on X-ray dose levels in electrophysiology procedures.

Aims This study presents and evaluates the impact of a new lowest-dose fluoroscopy protocol (Siemens AG), especially designed for electrophysiology (EP) procedures, on X-ray dose levels. Methods and results From October 2014 to March 2015, 140 patients underwent an EP study on an Artis zee angiography system. The standard low-dose protocol was operated at 23 nGy (fluoroscopy) and at 120 nGy (cine-loop), the new lowest-dose protocol was operated at 8 nGy (fluoroscopy) and at 36 nGy (cine-loop). Procedural data, X-ray times, and doses were analysed in 100 complex left atrial and in 40 standard EP procedures. The resulting dose-area products were 877.9 +/- 624.7 mu Gym(2) (n = 50 complex procedures, standard low dose), 199 +/- 159.6 mu Gym(2) (n = 50 complex procedures, lowest dose), 387.7 +/- 36.0 mu Gym(2) (n = 20 standard procedures, standard low dose), and 90.7 +/- 62.3 mu Gym(2) (n = 20 standard procedures, lowest dose), P < 0.01. In the low-dose and lowest-dose groups, procedure times were 132.6 +/- 35.7 vs. 126.7 +/- 34.7 min (P = 0.40, complex procedures) and 72.3 +/- 20.9 vs. 85.2 +/- 44.1 min (P = 0.24, standard procedures), radiofrequency (RF) times were 53.8 +/- 26.1 vs. 50.4 +/- 29.4 min (P = 0.54, complex procedures) and 10.1 +/- 9.9 vs. 12.2 +/- 14.7 min (P = 0.60, standard procedures). One complication occurred in the standard low-dose and lowest-dose groups (P = 1.0). Conclusion The new lowest-dose imaging protocol reduces X-ray dose levels by 77% compared with the currently available standard low-dose protocol. From an operator standpoint, lowest X-ray dose levels create a different, reduced image quality. The new image quality did not significantly affect procedure or RF times and did not result in higher complication rates. Regarding radiological protection, operating at lowest-dose settings should become standard in EP procedures.