Baroreflex sensitivity and cardiopulmonary blood volume in normotensive and hypertensive patients.
AUTOR(ES)
Simon, A C
RESUMO
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.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=483319Documentos Relacionados
- Cardiac effects of chronic renal failure and haemodialysis treatment. Hypertensive versus normotensive patients.
- Cardiac output and distribution of blood volume in central and peripheral circulations in hypertensive and normotensive man.
- Nocturnal blood pressure profiles among normotensive, controlled hypertensive and refractory hypertensive subjects
- Plasma urea in hypertensive patients.
- Disturbed noradrenergic blood pressure control in normotensive members of hypertensive families.