Flow effect on lesion formation in RF cardiac catheter ablation

This study investigated the flow effect on the lesion formation during radi o-frequency cardiac catheter ablation in temperature-controlled mode. The b lood flow in heart chambers carries heat away from the endocardium by conve ction, This cooling effect requires more power from the ablation generator and causes a larger lesion. We set up a flow system to simulate the flow in side the heart chamber. We performed in vitro ablation on bovine myocardium with three different flow rates (0 L/min, 1 L/min and 3 L/min) and two tar get temperatures (60 degreesC and 80 degreesC). During ablation, we also re corded the temperatures inside the myocardium with a three-thermocouple tem perature probe. The results show that lesion dimensions (maximum depth, max imum width and lesion volume) are larger in high flow rates (p < 0.01), Als o, the temperature recordings show that the tissue temperature rises faster and reaches a higher temperature under higher flow rate.