[Development and validation of a model for radiofrequency ablation].
Since 1986, cardiac arrhythmias have been successfully treated by destroying the underlying arrhythmogenic substrate with radiofrequency energy (radiofrequency ablation). The aim of this study was to develop a model for radiofrequency ablation enabling evaluation of the temperature distribution within cardiac tissue and the influence of electrode tissue contact. The model describes a 7F electrode, 4 mm in length and positioned perpendicular to the tissue. Heat convection within the tissue and heat lost via the blood was taken into account. Simulation of constant tissue exposure to 4 W resulted in a temperature increase of 35 degrees C after 10 sec. The temperature increase in the depths was less steep, but constant, and exceeded the electrode temperature at depths of 1 mm after 40 sec, 2 mm after 100 sec, and 3 mm after 200 sec. Electrode tissue contact proved to have a great influence on tissue temperature. Poor contact resulted in a temperature rise of only 0.68 degree C with a maximum of 50 W, whereas with ideal contact, 4 W sufficed to achieve a chosen setpoint of 70 degrees C. The model was validated in an in vitro setup using ventricular tissue from the pig. A strong correlation was found between simulated heating efficiency during temperature-controlled ablations under different contact conditions, and the respective measured values in the in vitro setup with a correlation coefficient of 0.97.
Eick
O J
OJ
Medtronic Bakken Research Center, Maastricht, The Netherlands. Olaf.Eick@medtronic.com
D000818:Animals; D001145:Arrhythmias, Cardiac / Q000628:therapy; D017115:Catheter Ablation / Q000295:instrumentation* / Q000379:methods*; D006321:Heart; D006801:Humans; D066298:In Vitro Techniques; D008954:Models, Biological; D015203:Reproducibility of Results; D013552:Swine; D013696:Temperature
Entwicklung und Validierung eines Modells zur Hochfrequenzablation.