Conceptus radiation dose and risk from cardiac catheter ablation procedures

The aim of the current study was to estimate the conceptus radiation dose and risk associated with fluoroscopic imaging during a catheter ablation procedure for supraventricular tachycardia performed on the expectant mother.

Exposure parameters and fluoroscopy times for each projection of the cardiac ablation procedure performed in 20 female patients of childbearing age were recorded. Radiation doses for a potential conceptus were estimated by using dose data obtained in anthropomorphic phantoms simulating pregnancy at the first, second, and third trimesters. Dose measurements were carried out using thermoluminescent dosimeters. For a typical examination, the average radiation dose to the conceptus was <1 mGy in all periods of gestation. Average excess fatal cancer was 14.5/10(6) unborn children irradiated during the first postconception weeks. Corresponding values for the second and third trimesters were 30 and 55.7/10(6), respectively. The risk for hereditary effects in future generations was 1.5/10(6) cases for conceptus irradiation during the first postconception weeks. Corresponding values for the second and third trimesters were 3.0 and 5.6/10(6), respectively. Formulas and dose data are presented for estimating the conceptus risk from any technique and x-ray system used for catheter ablation procedures.

A typical catheter ablation procedure results in a very small increase in risk of harmful effects to the conceptus. However, estimation of conceptus dose from catheter ablation procedures is always needed to assess the risk to the individual developing in utero.