Possible influence of hemodynamic and neurohormonal factors on the heart's response to arterial hypertension

Hypertrophy represents a frequent but inconstant response of the heart to hypertension and probably other nonhemodynamic factors are involved. We have performed 2D and Doppler echocardiography and assessed of neurohumoral pattern in 85 untreated patients with hypertension (diastolic blood pressure: 101 +/- 12.8 mmHg). Left ventricular hypertrophy was defined as a mass index greater than 134 g/m2 in males and 110 g/m2 in females. Doppler evaluation of left ventricular filling pattern was performed to detect the possible association of hypertrophy and diastolic dysfunction. In all patients the following neurohumoral substances were sampled and tested: plasmatic renin activity (PRA), aldosterone and norepinephrine. At Doppler echocardiography, 27 patients had hypertrophy and diastolic dysfunction, 15 only hypertrophy and 43 only diastolic dysfunction. The presence or absence of morpho-functional anomalies were independent of age, duration of hypertension and blood pressure levels. The mean value of neurohumoral substances were: norepinephrine 323.3 +/- 245 pg/ml, PRA 2.5 +/- 4 ng/ml/h, aldosterone 153.58 +/- 102 pg/ml. A significant correlation was found between PRA and blood pressure, and between aldosterone and all the Doppler-derived parameters of diastolic dysfunction. In conclusion, left ventricular hypertrophy seems to be related to alteration in ventricular geometry rather than to hemodynamic factors. Among nonhemodynamic factors, aldosterone may be the most responsible for abnormal filling, presumably through the activation of collagen matrix growth