In vivo left ventricular function and collagen expression in aldosterone/salt-induced hypertension

Cardiac fibrosis is linked to aldosterone-induced hypertension, but the eff ects on in vivo left ventricular (LV) function are not established. We stud ied the relations between in vivo LV function and aldosterone/salt cardiac fibrosis. Adult guinea pigs (GPs) were treated for 3 months with an aldoste rone infusion and high-salt diet. This treatment induced arterial hypertens ion (+35%) and moderate LV hypertrophy (LVH; +60%) without right ventricula r (RV) hypertrophy. Echo-Doppler LV assessment demonstrated unaltered cardi ac output, stroke volume, or LV relaxation. Spe I collagen messenger RNA (m RNA) was significantly increased in both ventricles (LV, +48%; RV,+77%) and accompanied by a significant increase in total collagen deposition (LV, fr om 0.52% in controls to 4.4% in treated GPs; RV, from 0.82 to 5.5% in treat ed GPs). Plasma norepinephrine levels increased 2.6-fold (p < 0.01) and cor related with the increase in collagen deposition in both ventricles. Collag en content was not correlated with hypertension or LVH. We conclude that al dosterone administration induces cardiac collagen accumulation and a sympat hetic stimulation, which might preserve systolic and diastolic function.