Inverse Relationship Between Electrode Size and Lesion Size During Radiofrequency Ablation With Active Electrode Cooling

Nakagawa, Hiroshi; Wittkampf, Fred H.M.; Yamanashi, William S.; Piťha, Jan; Imai, Shinobu; Campbell, Barclay; Arruda, Maurício; Lazzara, Ralph; Jackman, Warren M.

doi:10.1161/01.cir.98.5.458

Cited by 191 publications

(153 citation statements)

References 36 publications

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“…[12][13][14][15]19 In addition, experimental studies 20,21 and nonrandomized studies [12][13][14][15] Thus, ablation of typical AFL with an irrigated-tip catheter was recently recommended as first-line therapy. 22 Only 2 randomized studies demonstrated that both catheter techniques were equivalent, although several limitations were underlined.…”

Section: Comparison Between 8-mm-tip and Cooled-tip Cathetersmentioning

confidence: 99%

Effect of Isthmus Anatomy and Ablation Catheter on Radiofrequency Catheter Ablation of the Cavotricuspid Isthmus

Costa¹,

Faure²,

Thévénin³

et al. 2004

Circulation

113

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Background-Cavotricuspid isthmus (CTI) characteristics are rarely documented when comparing catheters in radiofrequency ablation (RFA) of atrial flutter (AFL). Our objectives were (1) to evaluate the impact of CTI morphology and length on ablation procedures and (2) to compare the efficacy of an 8-mm-tip catheter with an irrigated cooled-tip RFA in the subgroup presumed to be more difficult to treat (with a long CTI, Ͼ35 mm). Methods and Results-Over a period of 17 months, 185 patients accepted the protocol and underwent an isthmogram in preparation for RFA. Groups were classified according to CTI length and CTI morphology. RFA was performed with an 8-mm-tip catheter for patients with a short CTI, Յ35 mm (nϭ123), whereas randomization between an 8-mm-tip and a cooled-tip catheter applied to patients with a longer CTI, Ͼ35 mm (nϭ62). For long CTI, 32 patients were assigned to an 8-mm catheter and 30 patients to the cooled-tip RFA ablation group. In this subset, RF application (18.2Ϯ17 versus 19Ϯ13 minutes) and x-ray exposure (20.8Ϯ18 versus 18Ϯ13 minutes) did not differ between the 8-mm-tip and the cooled-tip procedures. Number of applications (9.9Ϯ11 versus 18.6Ϯ15 minutes; PϽ0.0001) and x-ray exposure (11.7Ϯ11 versus 19.5Ϯ16 minutes, Pϭ0.0001) differed significantly between patients with short and long CTIs.Patients with short and straight CTIs required 3 times fewer RFA applications and shorter x-ray exposure compared with other CTI morphologies (pouch-like recesses and concave characteristics). Conclusions-The number of RF applications required for a complete isthmus block in long CTIs is not influenced by the choice between an 8-mm or cooled-tip catheter. Procedure parameters, however, are significantly influenced by CTI length and morphology. Pouch-like recesses and concave characteristics account for much longer ablation times at all

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Section: Comparison Between 8-mm-tip and Cooled-tip Cathetersmentioning

confidence: 99%

Effect of Isthmus Anatomy and Ablation Catheter on Radiofrequency Catheter Ablation of the Cavotricuspid Isthmus

Costa¹,

Faure²,

Thévénin³

et al. 2004

Circulation

113

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“…Furthermore, on the basis of the heating efficiency equation postulated for endocardial ablation, 14 one might expect RFA efficiency with active cooling to be even greater on the epicardial surface. That is, given equivalent catheter-tissue contact, a fixed amount of power delivery could result in greater tissue absorption during epicardial ablation because of the absence of current shunting by the bloodstream.…”

Section: Epicardial Cooled-tip Rf Ablationmentioning

confidence: 99%

“…Specifically, saline cooling of the ablation electrode by external irrigation is known to be an effective means of generating deep endocardial RF lesions. 14,18 But in the pericardial space, (1) irrigation of the electrode with saline, a conductive solution, may increase the size of the virtual ablation electrode to uncontrollable dimensions because of the absence of the dispersing "buffering" effect of the bloodstream, and (2) the volume of infused fluid into the pericardial sac may alter the biophysical properties of each successive ablation pulse, necessitating manual aspiration of the pericardial space before each lesion. Also, no information is available regarding the use of large-tip (eg, 8-mm tip) catheters for epicardial mapping and ablation.…”

Section: Potential Clinical Implicationsmentioning

confidence: 99%

Catheter Ablation of Ventricular Epicardial Tissue

et al. 2004

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Background-Transthoracic epicardial catheter ablation is an emerging catheter ablation strategy being used clinically at increasing frequency. However, the efficacy of standard RF ablation on the epicardial surface of the heart is hindered by (1) the lack of convective cooling of the ablation electrode and (2) the varying presence of epicardial adipose tissue interposed between the ablation electrode and the target site. This experimental animal study examines the biophysical characteristics of radiofrequency (RF) ablation lesions generated by either standard or cooled-tip ablation of the ventricular epicardium. Methods and Results-Nonsurgical subxyphoid pericardial access was achieved in 10 normal goats and 7 pigs with healed myocardial infarctions. A 4-mm cooled-tip RF ablation catheter (continuous 0.9% saline circulation at 0.6 mL/s; goal temperature, 40°C; 60 seconds) was used to deliver epicardial ventricular lesions: 47 in normal tissue and 22 in infarcted tissue. Standard RF ablation lesions (nϭ33) using a 4-mm top catheter (goal temperature, 70°C; 60 seconds) were also placed on normal epicardial tissue. Lesions created with standard and cooled-tip RF ablation were 3.7Ϯ1.3 mm (25Ϯ16.8 W) and 6.7Ϯ1.7 mm (44.8Ϯ6.8 W) in depth, respectively. On scar tissue, lesions made with the cooled-tip catheter measured 14.6Ϯ2.7 mm in length, 11.8Ϯ2.9 mm in width, and 5.6Ϯ1.2 mm in depth (35.6Ϯ7.1 W). In areas covered by epicardial fat (3.1Ϯ1.2 mm thick), standard RF energy did not generate any appreciable lesions, but cooled-tip RF lesions were 4.1Ϯ2 mm in depth (45Ϯ4.4 W). Conclusions-Cooled-tip RF ablation can generate epicardial lesions more effectively than standard RF ablation and appears to be of particular benefit in ablating areas with overlying epicardial fat.

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“…Additionally, irrigation at the site of ablation has also helped to minimize thrombus formation at the ablation site as well. The saline used for irrigation can be circulated within the electrode (closed loop system), or open irrigation system that flushes saline through openings in the ablation electrode (Budde et al 1987, Grumbrecht et al 1998, Kongsgaard et al 1997, matsudairi et al 2003, Nakagawa et al 1998, Wittkampf et al 1989and Yokoyama et al 2006. A major limitation of this catheter is the poor correlation of the tip temperature with the tissue temperature, often resulting in RF being curtailed and therefore incomplete lesions are made.…”

Section: Irrigated Tip Electrode Cathetermentioning

confidence: 99%

Past, Present and Future Catheter Technologies and Energy Sources for Atrial Fibrillation Ablation

Singh¹,

Price²,

Leshen³

et al. 2012

Electrophysiology - From Plants to Heart

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Inverse Relationship Between Electrode Size and Lesion Size During Radiofrequency Ablation With Active Electrode Cooling

Abstract: The smaller electrode resulted in transmission of a greater fraction of the radiofrequency power to the tissue and resulted in higher tissue temperature, larger lesions, and lower dependency of lesion size on the electrode orientation.

Cited by 191 publications

References 36 publications

Effect of Isthmus Anatomy and Ablation Catheter on Radiofrequency Catheter Ablation of the Cavotricuspid Isthmus

Effect of Isthmus Anatomy and Ablation Catheter on Radiofrequency Catheter Ablation of the Cavotricuspid Isthmus

Catheter Ablation of Ventricular Epicardial Tissue

Past, Present and Future Catheter Technologies and Energy Sources for Atrial Fibrillation Ablation

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