Left Ventricle Radio-frequency Ablation in the Rat: A New Model of Heart Failure due to Myocardial Infarction Homogeneous in Size and Low in Mortality

Background: the purpose of the Current study was to create a model of myocardial infarction (MI) that is homogeneous in size with a low immediate (24 hours) mortality.Methods and Results: Male and female rats (n = 256) underwent left ventricle (LV) ablation (Ab) by a radiofrequency current (1000 kHz...

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Bibliographic Details
Authors: Antonio, Ednei L. [UNIFESP], Dos Santos, Alexandra A. [UNIFESP], Araujo, Sergio R. R. [UNIFESP], Bocalini, Danilo S. [UNIFESP], Dos Santos, Leonardo [UNIFESP], Fenelon, Guilherme [UNIFESP], Franco, Marcelo F. [UNIFESP], Tucci, Paulo. J. F. [UNIFESP]
Format: article
Status:Published version
Publication Date:2009
Country:Brasil
Institution:Universidade Federal de São Paulo (UNIFESP)
Repository:Repositório Institucional da UNIFESP
Language:English
OAI Identifier:oai:repositorio.unifesp.br:11600/31685
Online Access:http://dx.doi.org/10.1016/j.cardfail.2009.01.007
http://repositorio.unifesp.br/handle/11600/31685
Access Level:Open access
Keyword:Rats
myocardial infarction
radiofrequency ablation
heart failure
Description
Summary:Background: the purpose of the Current study was to create a model of myocardial infarction (MI) that is homogeneous in size with a low immediate (24 hours) mortality.Methods and Results: Male and female rats (n = 256) underwent left ventricle (LV) ablation (Ab) by a radiofrequency current (1000 kHz; 12 watts for 12 seconds) to promote a MI. A transmural MI occurred in all rats. Post-Ab complex arrhythmias were frequent (atrioventricular block, ventricular tachycardia, and fibrillation), which rapidly and spontaneously reverted to sinus rhythm. Among 66 male rats, immediate mortality occurred in 7.5%. Small NIT size dispersion was characterized by smaller variability following Ab (x +/- SD: 45 +/- 8%) when compared with coronary occlusion (Oc; 40 +/- 19%). the histopathologic evaluations identified lesions similar to those which occurred following Oc, with scarring complete at 4 weeks. the hemodynamic and Doppler echocardiograms showed comparable increases in LV dimension, end-diastolic pressure, and pulmonary water content I and 4 weeks post-MI. Papillary muscle mechanics 6 weeks post-MI had matched inotropic and lusitropic dysfunction.Conclusions: LV Ab gave rise to a MI within a narrow size limit and with a low immediate mortality. LV Ab resulted in histopathologic evolution. ventricular dilation, and dysfunction, impairment in myocardial mechanics, and congestive outcome that reproduced a MI from Oc. (J Cardiac Fail 2009;15;540-548)

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