RESUMO
With a view to determining to what extent changes in the position of the lower limbs influence post-ischaemic reactive hyperaemia, an ischaemic test was run on a group of normal subjects and patients with peripheral obliterative arteriopathy. Reactive hyperaemia was induced both in the usual supine position and then with the leg raised at 60 degrees to the horizontal. Raising of the leg significantly reduced the amplitude and duration of hyperaemia in both groups, though the differences between them with regard to the hyperaemic flow pattern were not affected. Various explanations of the results are offered. Raising of the limb appears to act more on local mechanisms controlling the peripheral arterial flow than on factors responsible for the genesis of RH. In particular, over and above the reduction of hydrostatic pressure, importance may be ascribed to the disequilibrium created by raising the limb on the component of vasal transparietal pressure. In arteriopaths, these factors are made more potent by obstruction of the main limb artery and arteriosclerotic impairment of the colateral circulation. Lastly, emphasis is placed on the possibility that the apparent metabolic deficiency created by ischaemia and remedied by RH is at least partly greater than the real deficiency and the tissues actual metabolic requirements.
Assuntos
Arteriosclerose/fisiopatologia , Hiperemia/fisiopatologia , Postura , Adulto , Idoso , Pressão Sanguínea , Doença das Coronárias/complicações , Doença das Coronárias/fisiopatologia , Humanos , Hiperemia/complicações , Perna (Membro) , Pessoa de Meia-IdadeRESUMO
Atherosclerosis brings about cardiovascular diseases and is the world's largest cause of death. Risk factors are to be considered in their incidence and correlation to various pathologies. Cholesterolaemia, smoking, physical inactivity, alcohol are held to be the most important risk factors. Hypercholesterolaemia involves a greater incidence of coronary heart disease; studies on cholesterol reduction however did not give evidence of any reduction in overall mortality. Alcohol displays an u-shaped relation between levels of assumption and associated mortality, depending on the fact that moderate drinkers show decreasing mortality scores and even a decreasing incidence of cardiovascular diseases (while the curve inflects upwards for serious drinkers). A direct correlation appears instead between both smoking and sedentary life on the one hand and both cardiovascular pathologies and mortality on the other. In order to reduce the risk factors' influence, on the ground of available studies and published trials do the authors offer practical indications. Fats in diet should be less than 30% of total calories (where of 10% saturated, 10% monounsaturated, 10% polyunsaturated); abstention from smoking must be absolute; alcohol should not exceed 15 g/die; some physical activity should be practised for 40-60 minutes, twice a week.