Obesity increases radiation dose delivered during atrial fibrillation ablation
Monday, 29 November 1999 19:00 | 
| Medicexchange News - Medicexchange News |
Obesity is a major determinant of the radiation dose delivered in patients undergoing atrial fibrillation (AF) ablation procedures, according to new findings.
Obesity is a major determinant of the radiation dose delivered in patients undergoing atrial fibrillation (AF) ablation procedures, according to findings published in the July 17th Journal of the American College of Cardiology.
"We hope our study will increase awareness of the important effect of patient weight on the radiation dose during complex ablation procedures," Dr. Joris Ector from University Hospital Gasthuisberg, University of Leuven in Belgium, told Reuters Health. "Currently, this aspect is frequently underappreciated by physicians performing these procedures."
Dr. Ector and colleagues evaluated the effect of obesity on radiation doses (as measured by dose-area product (DAP) and calculated effective dose) in 85 patients undergoing AF ablation under fluoroscopic guidance.
Body-mass index (BMI) strongly correlated with DAP, the authors report, whereas there was only a relatively weak correlation between fluoroscopy time and DAP.
Obese patients received 3.2 times the DAP of patients with a normal BMI during one hour of fluoroscopy.
Moreover, the researchers note, the calculated effective dose per hour of fluoroscopy was 2.2 times higher among obese patients than among patients with a normal BMI.
Five of six procedures in which the DAP exceeded 300 Gy*centimeter squared (an alert level for possible skin injury) involved obese patients.
"The high radiation exposure observed in obese patients in our study results in a worse risk-benefit ratio and should be considered when weighing the indication for AF ablation under fluoroscopic guidance," the investigators write. "When available, gadolinium-enhanced magnetic resonance imaging angiography is therefore preferable given the lack of extra radiation exposure to the patient."
"Many centers now use non-fluoroscopic 3D mapping systems to guide complex ablation procedures, thereby reducing radiation exposure for patients and physicians," Dr. Ector explained. "However, by using high-frame-rate pulsed fluoroscopy during limited periods of the procedure, the radiation dose (as expressed by the DAP) can reach levels comparable to the dose levels reported in our study (in which only fluoroscopic imaging was used, being it at a low frame-rate of three frames/second). The findings of our study should therefore not only be considered when performing ablation procedures under fluoroscopic guidance, but are of the same importance for centers using non-fluoroscopic mapping tools.
"We hope our study will increase awareness of the important effect of patient weight on the radiation dose during complex ablation procedures," Dr. Joris Ector from University Hospital Gasthuisberg, University of Leuven in Belgium, told Reuters Health. "Currently, this aspect is frequently underappreciated by physicians performing these procedures."
Dr. Ector and colleagues evaluated the effect of obesity on radiation doses (as measured by dose-area product (DAP) and calculated effective dose) in 85 patients undergoing AF ablation under fluoroscopic guidance.
Body-mass index (BMI) strongly correlated with DAP, the authors report, whereas there was only a relatively weak correlation between fluoroscopy time and DAP.
Obese patients received 3.2 times the DAP of patients with a normal BMI during one hour of fluoroscopy.
Moreover, the researchers note, the calculated effective dose per hour of fluoroscopy was 2.2 times higher among obese patients than among patients with a normal BMI.
Five of six procedures in which the DAP exceeded 300 Gy*centimeter squared (an alert level for possible skin injury) involved obese patients.
"The high radiation exposure observed in obese patients in our study results in a worse risk-benefit ratio and should be considered when weighing the indication for AF ablation under fluoroscopic guidance," the investigators write. "When available, gadolinium-enhanced magnetic resonance imaging angiography is therefore preferable given the lack of extra radiation exposure to the patient."
"Many centers now use non-fluoroscopic 3D mapping systems to guide complex ablation procedures, thereby reducing radiation exposure for patients and physicians," Dr. Ector explained. "However, by using high-frame-rate pulsed fluoroscopy during limited periods of the procedure, the radiation dose (as expressed by the DAP) can reach levels comparable to the dose levels reported in our study (in which only fluoroscopic imaging was used, being it at a low frame-rate of three frames/second). The findings of our study should therefore not only be considered when performing ablation procedures under fluoroscopic guidance, but are of the same importance for centers using non-fluoroscopic mapping tools.
