Estudo evolutivo da morfologia e funçäo cardíaca em ratos submetidos a estenose aórtica supravalvar / Follow-up study of morphology and cardiac function in rats undergoing induction of supravalvular aortic stenosis
Arq. bras. cardiol
;
81(6): 562-575, Dec. 2003. ilus, tab, graf
Article
in Portuguese, English
| LILACS
| ID: lil-356433
ABSTRACT
OBJECTIVE:
To characterize the follow-up of an experimental model of left ventricular hypertrophy (LVH) induced by supravalvular ascending aortic stenosis in young rats.METHODS:
Wistar rats were submitted to thoracotomy and aortic stenosis was created by placing a clip on the ascending aorta (AoS group, n=12). Age-matched control animals underwent a sham operation (C group, n=12). Cardiac function was analysed by echocardiograms performed 6, 12, and 21 weeks after aortic banding. Myocardial morphological features and myocardial hydroxyproline concentration (HOP) were evaluated 2, 6, 12, and 21 weeks after surgery in additional animals.RESULTS:
Aortic banding promoted early concentric LVH and a progressive increase in HOP. Under light microscopy, we observed myocyte hypertrophy and wall thickening of the intramural branches of the coronary arteries due to medial hypertrophy. Cardiac function was supranormal after 6 weeks (percentage of fractional shortening - EAo6 70.3±10.8; C6 61.3±5.4; p<0.05), and depressed in the last period. Diastolic dysfunction was detected after 12 weeks (ratio of early-to-late filling velocity - EAo12 4.20±3.25; C12 1.61±0.16; p<0.05).CONCLUSION:
Ascending aortic stenosis promotes concentric LVH with myocardial fibrosis and minimal histological changes. According to the period of evaluation, cardiac function may be improved, normal, or depressed. The model is suitable and useful for studies on pathophysiology and treatment of the different phases of cardiac hypertrophy
Full text:
Available
Index:
LILACS (Americas)
Main subject:
Hypertrophy, Left Ventricular
/
Aortic Stenosis, Supravalvular
/
Myocardium
Type of study:
Observational study
/
Prognostic study
Limits:
Animals
Language:
English
/
Portuguese
Journal:
Arq. bras. cardiol
Journal subject:
Cardiology
Year:
2003
Type:
Article
Affiliation country:
Brazil
Institution/Affiliation country:
Universidade Estadual Paulista/BR
Similar
MEDLINE
...
LILACS
LIS