Hypertensive heart disease: pathophysiology and clinical and prognostic consequences

The determinants of cardiac output were investigated in 161 patients with essential hypertension World Health Organization (WHO) stages I and II. In multiple regression analysis, cardiac output was inversely and independently related to blood pressure and to age. In patients with more severe hypertension, the lower cardiac output was associated with a lower stroke volume and a higher peripheral oxygen extraction. When age and blood pressure were taken into account, cardiac output was not a significant predictor of total mortality and of future cardiovascular events. Clinic and casual blood pressure explain only up to about 30% of the variability of echocardiographic left ventricular mass. The relationship of electrocardiographic voltages with blood pressure at various levels of bicycle exercise was highly significant in 169 patients with essential hypertension (r = 0.29-0.38; p less than 0.001) but the relationship was not better than with pressure at rest (r = 0.39). Ambulatory blood pressure, however, may be better related to left ventricular mass than clinic pressure. Several studies indicate that left ventricular hypertrophy is a significant risk factor for future cardiovascular events, independent of age and blood pressure. Left ventricular systolic function is usually normal in established hypertension, but diastolic function is frequently impaired, which could explain the reduced peak oxygen uptake in patients with more severe hypertension.