Arquivos Brasileiros de Cardiologia
Print version ISSN 0066-782X
BREGAGNOLLO, Edson Antonio et al. Effects of the prolonged inhibition of the angiotensin-converting enzyme on the morphological and functional characteristics of left ventricular hypertrophy in rats with persistent pressure overload. Arq. Bras. Cardiol. [online]. 2005, vol.84, n.3, pp. 225-232. ISSN 0066-782X. http://dx.doi.org/10.1590/S0066-782X2005000300006.
OBJECTIVE: To assess the effects of lisinopril (L) on mortality (M) rate and congestive heart failure (CHF), and the characteristics of geometrical myocardial remodeling and left ventricular function in rats with supravalvular aortic stenosis (SAS). METHODS: Some Wistar rats underwent SAS or the simulated surgery (CG, n=10). After 6 weeks, the animals were randomized to receive lisinopril (LG, n=30) or no treatment (SG, n=73) for 15 weeks. Cardiac remodeling was assessed in the sixth and 21st weeks after the surgical procedures through concomitant echocardiographic, hemodynamic, and morphological studies. RESULTS: The M were 53.9% and 16.7% in SG and LG, respectively; the incidence of CHF was 44.8% and 20%, in SG and LG, respectively, (P<0.05). At the end of the experiment, the values of LV systolic pressure in SG and LG were equivalent and significantly greater than those in CG;(P<0.05) and did not differ from those observed 6 weeks after the surgical procedures. The values of LV diastolic pressure in SG were greater than those in LG;(P<0.05), and both were greater than those in CG;(P<0.05). The same behavior was observed with the following variables: E/A ratio; mass index; sectional area of the myocytes; and LV hydroxyproline content. Left ventricular shortening percentage was similar in CG and LG;(P>0.05), and both were greater than those in SG;(P<0.05). Similar results were obtained with the values of the positive and negative first derivate of LV pressure. CONCLUSION: In rats with SAS, the treatment with L reduced M rate and ICC and had beneficial effects on geometrical myocardial remodeling and left ventricular function.
Keywords : cardiac hypertrophy; arterial hypertension; angiotensin-converting enzyme inhibitors; lisinopril; ventricular function.