Reducing Radiation Exposure in the Electrophysiology Laboratory: It is More Than Just Fluoroscopy Times!

Background: To exposure in patients undergoing cardiac electrophysiology (EP) ablation. This included the use of a "very low" dose protocol, and the impact of angulations and patient body mass index (BMI) on radiation dose as a mean to reduce exposure.

Methods: A total of 212 retrospective patient data sets were collected during EP ablation procedures on a biplane fluoroscopy system. Dose metrics were computed based on dose-area product (DAP) measured by the system for each x-ray acquisition.

Results: Dose baselines of different ablation procedures were established as DAP and DAP per hour, with respect to patient BMI. The use of a "very low dose" protocol reduced exposure by 62% while providing adequate image quality. With approximate left anterior oblique (LAO) 50° and right anterior oblique (RAO) 30°, DAP and DAP rate were significantly higher in LAO compared to RAO (11.2 [4.8-25.3] Gy · cm(2) vs 5.28 [2.9-11.1] Gy · cm(2) and 74.0 [38.2-136.1] Gy · cm(2)/h vs 25.0 [16.4-44.1] Gy · cm(2)/h, respectively; P < 0.001). DAP and DAP rate were also significantly higher in patients with BMI > 30 vs BMI ≤ 30 (34.2 [22.3-58.7] Gy · cm(2) vs 12.4 [6.0-26.9] Gy · cm(2) and 84.9 [68.1-120.4] Gy · cm(2)/h vs 34.2 [21.7-52.9] Gy · cm(2)/h, respectively; P < 0.001).

Conclusion: Protocol setting, system angulation, and BMI, in particular, wider angulation in LAO compared to RAO plane, exposes patients to significant higher radiation doses. Obese patients in standard LAO plane receive six times the radiation dose of nonobese patients in RAO.