Multifactorial evaluation of blood pressure fall upon hospitalization in essential hypertensive patients

1. Studies were prospectively performed on 72 hospitalized patients with essential hypertension. Blood pressure was normalized within 1 week of admission in 33 patients (group I), but did not decrease in 39 patients (group II). To determine the factors that differentiate group I from group II, cardio-renal haemodynamic and endocrinological indices were evaluated using multivariate analysis. 2. Systolic, diastolic and mean blood pressures on admission were higher in group II (P less than 0.001), whose optic fundi showed more severe changes (P less than 0.001). Although group II had greater left ventricular posterior wall thickness (P less than 0.02), left ventricular mass index (P less than 0.05) and systemic vascular resistance (P less than 0.01) on echocardiography, their cardiac index and ejection fraction were comparable with those of group I. 3. Renal blood flow (P less than 0.05) and glomerular filtration rate (P less than 0.01) were lower in group II than in group I. Renal vascular resistance was more elevated (P less than 0.01) in group II than in group I. 4. After severe sodium depletion and ambulation, group I showed a greater increase in plasma noradrenaline and adrenaline (P less than 0.05). On multivariate analysis, those with lower systolic blood pressure, better renal function and more reactive sympathetic nervous system were discriminated as group I. 5. These data suggest that group I patients have lower systolic blood pressure on admission, greater sympathetic reactivity and better renal function, all of which contribute to their spontaneous blood pressure fall after admission.