RESUMO
BACKGROUND: The use of fluoroscopic screening involves exposure to ionising radiation for both patients and operators. OBJECTIVE: To assess the effects of radiation dose reduction manoeuvres (DRM) during radiofrequency ablation (RFA) procedures. DESIGN: Prospective study of DRM. SETTING: Tertiary cardiac centre. Interventions Two DRM were combined: removal of the secondary radiation grid and programming an ultra-low pulsed fluoroscopy rate. These methods were assessed using an anthropomorphic phantom model to measure skin entrance dose rates. Procedures were classified as complex (ablation of atrial fibrillation, ventricular tachycardia or complex congenital heart disease arrhythmias) or simple (all other RFA). MAIN OUTCOME MEASURES: Dose area product and screening times were compared for ablations performed before and after DRM. Equivalent doses to organs and malignancy risk were determined by computer modelling. RESULTS: Over a 39-month period, 1007 ablation procedures were performed (631 simple, 376 complex). Radiation dose was significantly reduced after DRM for both simple (20.4±26.9 Gycm(2) vs 8.0±10.3 Gycm(2), p<0.00001) and complex ablations (63.3±50.1 Gycm(2) vs 32.8±31.7 Gycm(2), p<0.00001) with no difference in screening times. The mean lifetime risk of fatal cancer attributable to radiation exposure per million procedures was reduced from 182 to 68 for simple ablations and from 440 to 155 for complex ablations. CONCLUSIONS: Significant reductions in radiation exposure during RFA were achieved using simple DRM, corresponding to a two-thirds reduction of the risk of excess fatal malignancy.