Epicardial radiofrequency ablation of ventricular myocardium: Factors affecting lesion formation and damage to adjacent structures

dc.contributor.authorFenelon, G.
dc.contributor.authorPereira, K. P.
dc.contributor.authorPaola, AAV de
dc.contributor.institutionUniversidade Federal de São Paulo (UNIFESP)
dc.date.accessioned2016-01-24T12:38:16Z
dc.date.available2016-01-24T12:38:16Z
dc.date.issued2006-01-01
dc.description.abstractWe evaluated the factors affecting epicardial radiofrequency (RF) lesion formation in normal ventricular myocardium. in 16 dogs, a minithoracotomy was made and a sheath was placed in the pericardial space. Standard ablation lesions (4-mm tip catheter; 70 degrees C/60 seconds) were created in each ventricle under fluoroscopy guidance (n = 7) or hand-held with direct visualization of the catheter to assure optimal electrode-tissue contact (n = 6). in the latter, thermally-shielded (TS) electrodes (50% tip surface along its 4 mm length) were used in 3/6 dogs. Catheter tip (4 mm) irrigation (13 mL/minutes; 40 degrees C/60 seconds) was employed with conventional techniques in 3 additional dogs. Results: With optimal electrode-tissue contact (11 lesions), power (3.4 +/- 2.3 W vs. 16 +/- 13 W; p < 0.001) and pacing thresholds (0.2 +/- 0.0 mA vs. 3.6 +/- 5.7 mA; p = 0.004) were lower than standard RF (25 lesions). However, lesion dimensions were similar and transmural lesions did not occur (depth 2.8 +/- 1.1 mm vs. 3.0 +/- 1.5 mm). Catheter irrigation allowed high power outputs (43 +/- 6.1 W; p < 0.001) generating transmural lesions, 5/9 (55%), depth 6.4 +/- 2.1 mm. At constant power (2 W), catheter-tip temperature (52 +/- 5.2 degrees C vs. 57 +/- 6.6 degrees C; p = NS) and lesion (10 in each group) dimensions were similar for conventional and TS electrodes, but damage to parietal pericardium and lungs occurred with conventional electrodes only (70% vs. 0% p = 0.02). Conclusion: Standard epicardial RF ablation does not produce deep lesions and exhibits a significant energy loss probably due to poor electrode-tissue contact. Catheter irrigation allows delivery of high power outputs to the epicardium consistently creating deeper lesions than standard ablation. TS electrodes may reduce damage to neighboring structures during epicardial RF ablation.en
dc.description.affiliationUniversidade Federal de São Paulo, Paulista Sch Med, Dept Cardiol, BR-04039032 São Paulo, Brazil
dc.description.affiliationUnifespUniversidade Federal de São Paulo, Paulista Sch Med, Dept Cardiol, BR-04039032 São Paulo, Brazil
dc.description.sourceWeb of Science
dc.format.extent57-63
dc.identifierhttp://dx.doi.org/10.1007/s10840-006-7620-0
dc.identifier.citationJournal of Interventional Cardiac Electrophysiology. Dordrecht: Springer, v. 15, n. 1, p. 57-63, 2006.
dc.identifier.doi10.1007/s10840-006-7620-0
dc.identifier.issn1383-875X
dc.identifier.urihttp://repositorio.unifesp.br/handle/11600/28637
dc.identifier.wosWOS:000237341000009
dc.language.isoeng
dc.publisherSpringer
dc.relation.ispartofJournal of Interventional Cardiac Electrophysiology
dc.rightsAcesso restrito
dc.rights.licensehttp://www.springer.com/open+access/authors+rights?SGWID=0-176704-12-683201-0
dc.subjectarrhythmiasen
dc.subjectelectrophysiologyen
dc.subjectradiofrequency ablationen
dc.subjectpericardiumen
dc.titleEpicardial radiofrequency ablation of ventricular myocardium: Factors affecting lesion formation and damage to adjacent structuresen
dc.typeArtigo
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