Noncontact radio-frequency ablation for obtaining deeper lesions.
Radio-frequency (RF) cardiac catheter ablation has been very successful for treating some cardiac arrhythmias, however, the success rate for ventricular tachycardias is still not satisfactory. Some existing methods for developing deeper lesions include active cooling of the electrode and modifying the electrode shape. We propose a method of noncontact ablation, to solve this problem. We apply 120 W of power through an 8-mm electrode for a 120-s duration, with distances from 0 to 3 mm between electrode and myocardium, to create lesions in myocardium. We apply flow rates of 1, 3, and 5 L/min to determine their effect. Results show that with an optimal distance from 0.5 to 1.5 mm between electrode and myocardium, we increase lesion depth from 7.5 mm for contact ablation to 9.5 mm for noncontact ablation. For different flow rates, the optimal distance various. The effect of flow rate is not obvious. Higher flow rate does not lead to a deeper lesion.
Zhang
Jie
J
Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA.
Tsai
Jang-Zern
JZ
Cao
Hong
H
Chen
Yi
Y
Will
James A
JA
Vorperian
Vicken R
VR
Webster
John G
JG
D000818:Animals; D015374:Biosensing Techniques; D017115:Catheter Ablation / Q000295:instrumentation / Q000379:methods*; D002417:Cattle; D006352:Heart Ventricles / Q000528:radiation effects* / Q000601:surgery*; D006801:Humans; D066298:In Vitro Techniques; D011786:Quality Control; D000078702:Radiofrequency Therapy; D012680:Sensitivity and Specificity