Coil electrodes for RF ablation of atrial fibrillation

Long and contiguous lesions may cure AF. We analyzed a multielectrode steerable catheter capable of creating such lesions. For optimal temperature control purposes, based on analytical and experimental data, one temperature sensor was placed at each end of the long coil electrodes. In vitro ablations were performed to analyze the catheter performance. At set temperatures of 70/spl deg/C, 85% of the lesions were contiguous. All lesions created at set temperatures of 80 and 90/spl deg/C were contiguous. No sudden impedance rises occurred. The lesion length increased linearly with the number of electrodes. Power to reach set temperature was larger and the impedance decreased as more electrodes were connected in the ablation circuit.