Relative role of left ventricular geometric remodeling and of morphological and functional myocardial remodeling in the transition from compensated hypertrophy to heart failure in rats with supravalvar aortic stenosis.
OBJECTIVE
To evaluate the relative contribution of left ventricular (LV) geometric remodeling and of morphological and functional myocardial changes in rats with induced supravalvar aortic stenosis (SAS), in the transition from compensated hypertrophy to congestive heart failure (CHF).


METHODS
Twenty one weeks after induction of SAS, the rats were classified as controls (CG, n=13), without congestive heart failure (SG, n=11), or with congestive heart failure (SG-HF, n=12). All groups were evaluated with echocardiographic, hemodynamic and morphological study of the myocardium.


RESULTS
Twenty one weeks after SAS: mass index (SG-HF>SG>CG, p<0.05); systolic pressure (SG-HF= SG>CG, p<0.05); diastolic pressure (SG-HF>SG>CG, p<0.05); systolic and diastolic meridional stress (SG-HF>SG>CG, p<0.05); LV myocyte cross-sectional area (SG-HF>SG>CG, p<0.05) and hydroxyproline content (SG-HF>SG>CG, p<0.05). In the SG-HF group, LV geometric remodeling was characterized by a significant increase in dimensions and relative thickness of the normal wall (excentric remodeling), whereas the SG group presented a concentric remodeling. Indexes of LV performance in the SG-HF group were significantly lower than those of the SG group.


CONCLUSIONS
The SG-HF and SG groups differed primarily in the LV geometric remodeling and structural myocardial remodeling process, which established a chronically compensated state in the SG group and triggered CHF in the SG-HF group in the presence of equivalent degrees of impaired contractility.
Bregagnollo
Edson Antonio
EA
Faculdade de Medicina de Botucatu, Universidade Estadual de São Paulo, Brazil. bregagnollogh@ig.com.br
Mestrinel
Marco Aurélio
MA
Okoshi
Katashi
K
Carvalho
Fábio Cardoso
FC
Bregagnollo
Isamara Fernanda
IF
Padovani
Carlos Roberto
CR
Cicogna
Antonio Carlos
AC
D000818:Animals; D021921:Aortic Stenosis, Supravalvular / Q000150:complications / Q000503:physiopathology*; D004195:Disease Models, Animal; D004452:Echocardiography; D006333:Heart Failure / Q000209:etiology / Q000503:physiopathology*; D017379:Hypertrophy, Left Ventricular / Q000150:complications / Q000473:pathology / Q000503:physiopathology*; D008297:Male; D009200:Myocardial Contraction / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D020257:Ventricular Remodeling / Q000502:physiology*