Document Detail

Indication of the radiofrequency induced lesion size by pre-ablation measurements.
MedLine Citation:
PMID:  16216752     Owner:  NLM     Status:  MEDLINE    
BACKGROUND: During radiofrequency ablation of arrhythmias tissue heating and hence lesion size depend on electrode-tissue contact and cooling of the electrode tip caused by cavitary blood flow. These factors are unique and unknown for each catheter placement in the beating heart. A tool for assessing these factors prior to ablation may indicate the lesion size which will be obtained for any given catheter position. METHODS AND RESULTS: Radiofrequency ablation was performed in vitro on strips of left ventricular porcine myocardium during two different levels of convective cooling (0 or 0.1 m/s), two different contact pressures (10 or 30 g) and parallel or perpendicular electrode-tissue orientation using 7F 4 mm tip catheters. Prior to ablation the impedance rise (DeltaIMP) caused by the obtained contact and the temperature rise with a 0.6 W 5 s test pulse (DeltaT) were measured. Subsequently, during unchanged conditions, radiofrequency ablation was performed as either temperature-controlled, power-controlled or irrigated tip ablation and lesion size was determined. DeltaIMP increased significantly (P < 0.05) by improved contact, whereas it was not affected by convective cooling. DeltaT was significantly increased by increasing contact pressure (P < 0.05) and significantly decreased by increased cooling (P < 0.001). DeltaT was not systematically affected by electrode orientation. The product of DeltaT and DeltaIMP showed a significant correlation between the obtained lesion size and power output for temperature-controlled and between lesion size and tip temperature for power-controlled ablation (P < 0.001). CONCLUSIONS: Pre-ablation measurement of DeltaIMP and DeltaT can indicate the lesion size resulting after ablation in temperature-controlled, power-controlled and irrigated ablation in vitro, since DeltaT reflects cavitary cooling and to a smaller extent electrode-tissue contact, and DeltaIMP reflects only electrode-tissue contact.
Niels Stagegaard; Helen Høgh Petersen; Xu Chen; Jesper Hastrup Svendsen
Publication Detail:
Type:  In Vitro; Journal Article; Research Support, Non-U.S. Gov't     Date:  2005-09-08
Journal Detail:
Title:  Europace : European pacing, arrhythmias, and cardiac electrophysiology : journal of the working groups on cardiac pacing, arrhythmias, and cardiac cellular electrophysiology of the European Society of Cardiology     Volume:  7     ISSN:  1099-5129     ISO Abbreviation:  Europace     Publication Date:  2005 Nov 
Date Detail:
Created Date:  2005-10-11     Completed Date:  2006-02-14     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  100883649     Medline TA:  Europace     Country:  England    
Other Details:
Languages:  eng     Pagination:  525-34     Citation Subset:  IM    
Medical Department B 2012, The Heart Centre, Rigshospitalet, National University Hospital, Blegdamsvej 9, 2100 Copenhagen, Denmark.
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MeSH Terms
Catheter Ablation*
Electric Impedance
Myocardium / pathology*

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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