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

Nsah, Emmanuel; Berger, Ronald D.; Rosenthal, Larry; Hui, Richard; Ramza, Brian; Jumrussirikul, Pitayadet; Lawrence, John H.; Tomaselli, Gordon F.; Kass, David A.; Calkins, Hugh

doi:10.1016/s0002-8703(98)70130-9

Cited by 13 publications

(18 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…8 A linearly increasing fall in impedance with an increasing catheter tip temperature has been described for nonirrigated ablation. 4,9,10 This has been suggested to be because of increased conductivity of cardiac tissue with heating.…”

Section: Discussionmentioning

confidence: 99%

Target Indices for Clinical Ablation in Atrial Fibrillation

Ullah

Hunter

Baker

et al. 2014

Circ: Arrhythmia and Electrophysiology

View full text Add to dashboard Cite

Background-In animal studies of radiofrequency ablation, lesion sizes plateau as the maximum lesion size is reached for an ablation. Lesion parameters are not available in clinical ablations, but preclinical work suggests that these correlate with impedance drop and electrogram attenuation. Characterization of the relationships between catheter contact force, ablation duration, and these surrogate markers of lesion formation may allow us to define targets for effective ablation. Methods and Results-Fifteen patients undergoing first-time radiofrequency ablation for nonparoxysmal atrial fibrillation were studied. All were in atrial fibrillation at the time of the procedure. Ablations were performed with an irrigated-tip contact force-sensing catheter in temperature-controlled mode (temperature limited to 48°C, power to 30 W). Included were 285 left atrial static ablations, 247 with additional impedance data. The ablation force time integral (FTI) correlated with the attenuation of the electrogram with ablation (Spearman ρ, -0.14; P=0.02): the relationship plateauing from 500 g·s, a reduction in the electrogram amplitude of 20%. The FTI also correlated with the impedance drop during ablation (Spearman ρ, 0.79; P<0.0005): the relationship was logarithmic, the reduction in the impedance with an increasing FTI also plateauing from 500 g·s, an impedance drop of 7.5%. The ablation duration affected the impedance drop at an FTI if the duration was <10 s. Beyond this time point, the FTI achieved rather than the ablation duration or mean contact force applied determined the impedance drop. Conclusions-During nonparoxysmal atrial fibrillation ablation, an FTI of 500 g·s should be targeted with ablation duration of ≥10 s. Clinical Trials Registration-URL: http://clinicaltrials.gov/. Unique Identifier: NCT01587404.(Circ Arrhythm Electrophysiol. 2014;7:63-68.)

show abstract

Section: Discussionmentioning

confidence: 99%

Target Indices for Clinical Ablation in Atrial Fibrillation

Ullah

Hunter

Baker

et al. 2014

Circ: Arrhythmia and Electrophysiology

View full text Add to dashboard Cite

show abstract

“…12,20 Radiofrequency ablation transfers high-frequency alternating current into tissue within the treatment zone. 4,5,23 Ionic agitation in the tissue creates thermal energy and subsequent tissue destruction; irreversible destruction typically occurs at temperatures of approximately 50°C. When temperature rise above 100°C, development of a tissue coagulum can cause an abrupt increase in impedance with reduced current flow and decreased lesion growth.…”

Section: Discussionmentioning

confidence: 99%

“…Impedance may also be affected by the tissue composition of the target organ. 4,5,23 The goal of our study was to evaluate in normal renal tissue the efficacy, reproducibility, and completeness of cellular necrosis with the available RF generators using the manufacturer's treatment recommendations. In all cases, RF energy was tolerated without perioperative complications.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Radiofrequency Coagulation of Renal Parenchyma: Comparison of Effects of Energy Generators on Treatment Efficacy

Gettman

Lotan²,

Corwin

et al. 2002

Journal of Endourology

View full text Add to dashboard Cite

show abstract

“…Numerous RFCA clinical studies on 4-mm (7 Fr) electrodes have reported impedance values around 100 Ω, e.g. 113±10 Ω in 45 patients [12], 103.5±8.6 Ω in 76 patients [13], 100±9 Ω in 29 patients [14]. …”

Section: Estimate From Clinical Datamentioning

confidence: 99%

Lumped Element Electrical Model based on Three Resistors for Electrical Impedance in Radiofrequency Cardiac Ablation: Estimations from Analytical Calculations and Clinical Data

Berjano

d’Ávila²

2013

TOBEJ

View full text Add to dashboard Cite

The electrical impedance measured during radiofrequency cardiac ablation (RFCA) is widely used in clinical studies to predict the heating evolution and hence the success of the procedure. We hypothesized that a model based on three resistors in series can mimic the total electrical impedance measured during RFCA. The three resistors or impedances are given by: impedance associated with the tissue around the active electrode (myocardium and circulating blood) (Z-A), that associated with the tissue around the dispersive electrode (Z-DE) and that associated with the rest of the body (Z-B). Our objective was to quantify the values associated with these three impedance types by an analytical method, after which the values obtained would be compared to those estimated from clinical data from previous studies. The results suggest that an RFCA using a 7 Fr 4-mm electrode would give a Z-A of around 75 ohms, a Z-DE around 20 ohms, and Z-B would be 15±10 ohms (for body surface area variations between 1.5 and 2.5 m^2). Finally, adaptations of the proposed model were used to explain the results of previous clinical studies using a different electrode arrangement, such as in bipolar ablation of the ventricular septum.

show abstract

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

Cited by 13 publications

References 26 publications

Target Indices for Clinical Ablation in Atrial Fibrillation

Target Indices for Clinical Ablation in Atrial Fibrillation

Radiofrequency Coagulation of Renal Parenchyma: Comparison of Effects of Energy Generators on Treatment Efficacy

Lumped Element Electrical Model based on Three Resistors for Electrical Impedance in Radiofrequency Cardiac Ablation: Estimations from Analytical Calculations and Clinical Data

Contact Info

Product

Resources

About