ISSN:
1572-8595
Keywords:
catheter ablation
;
cryotherapy
;
isothermic period
;
arrhythmia
;
lesion size
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract A prototype steerable 8.5F bipolar catheter fitted with a feedback thermocouple was tested in 7 anaesthetized pigs (30 kg) guided by the electrocardiogram in order to modify the AV nodal and His-Purkinje system conductive properties. Thermal energy was delivered by a pressurized N 2O tank (〉650 psi) via a cardiac cryo unit (Spembly, Hampshire, UK) into the catheter wherein gas expands resulting in a tip temperature as low as −70 ± 2°C within 10 seconds. Cryoablation under fluoroscopic and electrocardiographic guidance was applied at distinct sites in both ventricles for 60 or 120 seconds. After a follow-up period of 6 weeks, the ablation lesions found were well demarcated with small margins of hypertrophy of myocardial cells. With respect to lesion volume variability (8–207 mm 3) and geometry, a relationship between the 0°C isothermic period and cryolesion volume was found. Results of an in vitro model corroborated this relationship. Therefore, an isothermic period probably can predict the lesion size and its geometry in terms of lesion depth. This potential therapeutic mode of transcatheter cryoablation deserves further investigation.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1009777024597
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