Hemorheologic Effects of Vasodilation in Essential Hypertension
| Autor: | Marian Wysocki, Ulf Bagge, Magnus Braide, Ove K. Andersson, B. Persson |
|---|---|
| Rok vydání: | 1996 |
| Předmět: |
Male
Vasodilator Agents Blood viscosity Hemodynamics 030204 cardiovascular system & hematology Hematocrit Essential hypertension 030226 pharmacology & pharmacy 03 medical and health sciences 0302 clinical medicine Double-Blind Method Humans Medicine Cadralazine Antihypertensive Agents Cross-Over Studies medicine.diagnostic_test business.industry Middle Aged Blood Viscosity medicine.disease Pyridazines Vasodilation Blood pressure medicine.anatomical_structure Anesthesia Hemorheology Hypertension Vascular resistance Vascular Resistance Cardiology and Cardiovascular Medicine business medicine.drug |
| Zdroj: | Angiology. 47:869-878 |
| ISSN: | 1940-1574 0003-3197 |
| DOI: | 10.1177/000331979604700905 |
| Popis: | Arterial hypertension is often associated with plasma volume contraction and hemocon centration, which negatively affect the vascular flow resistance and microcirculation. Since some antihypertensive drugs can affect blood rheology, the purpose of this study was to evaluate whether acute and long-term arterial vasodilation with cadralazine influ ences rheologic parameters in essential hypertension. Twelve patients with unsatisfacto rily controlled essential hypertension were studied. In the acute double-blind phase of the study the patients were allocated to treatment with either cadralazine or placebo. Intraarterial blood pressure, cardiac output (dye dilution), and blood rheology (viscosity, hematocrit) were registered before and after the first dose of cadralazine. Then 9 patients (3 dropouts) were treated with cadralazine and placebo during two four-week crossover periods and continued with cadralazine medication during the eight-week open phase of the study. Blood pressure and blood hemoglobin were followed during long-term treatment. A single oral dose of cadralazine caused vasodilation (total peripheral resistance index decreased from 45 to 33 U × m2, P < 0.05), which was accompanied by hemodi lution (hematocrit declined from 46.9% to 42.5%, P < 0.05) and a blood viscosity reduction of more than 10%. Viscosity of 45% suspension of erythrocytes in plasma was also reduced, suggesting a possible modification of the microrheologic factors. The changes in total peripheral resistance correlated negatively with the changes in hemat ocrit. An antihypertensive effect of cadralazine was still observed during the chronic phase of the study, which was not accompanied by hemodilution. It is concluded that arterial vasodilation with cadralazine reduces flow resistance in the circulatory system in hypertension and has acute rheologic effects that disappear during chronic medication. |
| Databáze: | OpenAIRE |
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