Towards optical monitoring of radiofrequency ablation extent for atrial fibrillation

Radiofrequency catheter ablation (RFA) therapy has emerged as a leading tool for the treatment of cardiac arrhythmias, including atrial fibrillation. Despite the widespread use, current devices possess considerable limitations in confirming successful lesion formation, in vivo. As a result, many clinical benefits are observed after multiple procedures to address recurrence. In this study, a catheter was designed conducive for real-time tissue optical measurements of the RFA treated zone. We found that RFA treated tissue exhibited a significant change in diffuse reflectance compared to the normal myocardium in ex vivo human samples. An algorithm was developed to invert diffuse reflectance into tissue optical properties. It is observed that transmural lesions exhibit an increased absorption and decreased reflectance as compared to normal and superficial lesions. Results are in agreement with published findings for thermally treated myocardium.