No abstract

No abstract

No abstract

No abstract

S U M M A R Y1. A haemodynamic study which included estimation of cardiopulmonary blood volume (CPBV), total blood volume (TBV) and vascular reactivity to noradrenaline was performed in seventeen borderline and sixteen permanent hypertensive patients.2. Borderline hypertensive patients had higher values of cardiac index, stroke index and heart rate when compared with the permanent hypertensive patients, and lower values of blood pressure and total peripheral resistance.3. The CPBVITBV ratio was significantly higher in borderline hypertensive patients. In that group, this ratio was directly correlated with cardiac index, stroke index and the pressor dose of noradrenaline (P ~0.01). 4. In permanent hypertensive patients, none of these correlations was observed.Only the total blood volume was correlated directly with cardiac index and inversely with total peripheral resistance. 5.The study suggests that a redistribution of intravascular volume from peripheral veins to the cardiopulmonary capacitance bed occurs in borderline hypertension when compared with permanent hypertension and that hypertension is related to a neural mechanism in the borderline state and to a volume mechanism in the permanent state.

Although all the subjects showed lowering of BP after surgery, and the age-BP relationship was restored, the long-term cure rate of APA subjects was 40%. The UAAR ratio, by comparison with other classical hormonal features of primary aldosteronism, was the best independent predictor of the cure of hypertension after adrenalectomy.

Baroreflex sensitivity and cardiopulmonary blood volume were determined in 95 men, including normotensive and hypertensive subjects with normal renal function and balanced sodium intake and urinary output. Baroreflex sensitivity was estimated by determining the slope of the regression line relating the increase of systolic pressure to the cardiac slowing after transient rises of arterial pressure. A technique of gradual atropinisation was used to evaluate the parasympathetic mediated component of the reflex. With this method, it was possible to calculate the exact atropine dose abolishing the reflex sensitivity. This index was not dependent on age. It was negatively correlated to the diastolic pressure in normotensive patients but not in hypertensive patients. The ratio between the cardiopulmonary and the total blood volume was considered as an index of sympathetic venous tone. This ratio was positively correlated to the diastolic pressure in normotensive patients, but not in hypertensive patients. This study strongly suggests that a precise sympathetic-parasympathetic balance existed in the normotensive patients. This balance was disrupted in the hypertensive patients pointing to abnormalities in the autonomic nervous system of permanently hypertensive patients.

No abstract