Biophysics of ablation: Application to technology

Introduction: The question of what happens to tissue during radiofrequency (RF) catheter ablation continues to be asked as we evolve into the use of newer delivery systems. Methods and Results: Three assumptions are made about RF ablation. (1) Tissue injury is thermally mediated; (2) heat transfer in tissue should be a predictable biophysical phenomenon; and (3) large lesion technologies have more or less equivalent efficacies. Based on these assumptions, predictions are made and discussed. Many of the predictors were proven to be true while some surprisingly were not. Conclusion: In conclusion, tissue-area injury occurs reproducibly at a temperature of about 50degreesC. Heat transfer in tissue is a predictable phenomenon. And finally, new technologies for large lesions are all effective, but greater surface area of ablation was achieved with a 10-mm tip and greater depth was achieved with a Chilli(R) cooled ablation catheter.