Relation between impedance and electrode temperature during radiofrequency catheter ablation of accessory pathways and atrioventricular nodal reentrant tachycardia

• Published in: The American heart journal 1998-11, Vol.136 (5), p.844-851
• Main Authors: Nsah, Emmanuel, Berger, Ronald, Rosenthal, Larry, Hui, Richard, Ramza, Brian, Jumrussirikul, Pitayadet, Lawrence, John H., Tomaselli, Gordon, Kass, David, Calkins, Hugh
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aged; Biological and medical sciences; Catheter Ablation - methods; Confounding Factors (Epidemiology); Diseases of the cardiovascular system; Electric Impedance; Electrodes; Female; Humans; Male; Medical sciences; Middle Aged; Predictive Value of Tests; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects); Sensitivity and Specificity; Tachycardia, Atrioventricular Nodal Reentry - surgery; Temperature
• ISSN: 0002-8703; 1097-6744
• DOI: 10.1016/S0002-8703(98)70130-9

Objectives Impedance monitoring has been proposed as a method to assess the adequacy of tissue heating during catheter ablation procedures. The purpose of this study was to evaluate the relation among initial impedance, fall in impedance, and electrode temperature during catheter ablation procedures. Methods and Results Data from 248 applications of radiofrequency energy in 45 consecutive patients (26 with accessory pathways and 19 with atrioventricular nodal reentrant tachycardia) referred for catheter ablation were analyzed. The initial impedance was higher during ablation of accessory pathways than during atrioventricular nodal reentrant tachycardia (116 ± 66 versus 106 ± 80 Ω, P < .001). In both groups, a significant correlation was observed between the initial impedance and temperature ( R = 0.98, P < .001). After accounting for differences between patients and ablation targets, an even closer correlation was observed (accessory pathways: R = 0.95, P < .0001; atrioventricular nodal reentrant tachycardia: R = 0.94, P < .0001). Conclusion These data suggest that monitoring of the initial impedance and the fall in impedance during ablation procedures may provide clinically valuable information to assess the efficacy of tissue heating and lesion formation. (Am Heart J 1998;136:844-51.)