RADIATION EXPOSURE TO PATIENT AND OPERATOR DURING RADIOFREQUENCY ABLATION FOR SUPRAVENTRICULAR TACHYCARDIA

Aim: To quantitate radiation exposure to patient and operator during R F ablation for supraventricular tachycardia. Methods: Thermoluminescen t dosemeters were used to monitor radiation at seven sites. Positions were: patient's thyroid, left scapula, T9 vertebra, right scapula and L4-L5 vertebra and the operator's thyroid and left hand. Monitoring wa s performed during 22 procedures. Of the patients studied 10 (45%) had atrioventricular junctional re-entry tachycardia (AVJRT) and 12 (55%) had accessory pathway tachycardia. Results: The median fluoroscopy ti mes (minutes) and inter-quartile ranges were 46 (39-65) for AVJRT, 55 (52-60) for left free wall accessory pathway(LFW), 107 (89-140) for se ptal and 166 (128-176) for RFW pathways. The mean radiation doses (mGy ) to the chest wall were 50 for AVJRT, 47 for LFW, 87 for septal and 1 51 for RFW pathways. The mean radiation to the chest wall of the patie nt per case was found to be 3.9 times that reported for diagnostic car diac catheterisation and 1.5 times that reported for angioplasty. Conc lusions: Radiofrequency ablation is associated with significant irradi ation of the patient and operator. All precautions should be taken to decrease this exposure. If eye irradiation is assumed to be equal to t hat to the thyroid more than 45 procedures per month by a single opera tor (using ceiling-suspended lead glass shielding) may result in excee ding the recommended dose limit to the eye.