Temperature distribution under cooled electrodes during radiofrequency catheter ablation

Larger lesions were created when the electrode of an RF ablation system was actively cooled below blood temperature. To keep the maximal tissue temperature at about 90/spl deg/C, significantly more RF power had to be delivered. Because the hottest tissue region moved farther from the electrode surface, it was more difficult to predict the adequate tissue heating. Therefore, the probability of overheating the tissue and producing micro-explosions increased.