Aging and the cardiovascular system.

With advancing age blood pressure rises in most populations with the exception of some isolated tribes. In western countries 30 to 40% of the people above the age of 60 years have casual blood pressure levels greater than or equal to 160/95 mm Hg. Advancing age per se produces a number of physiological changes related to blood pressure, such as a decrease in cardiac output, an increase in peripheral vascular resistance and a decrease in plasma renin-angiotensin-aldosterone levels. The mechanism causing the elevation in pressure with age are unknown though increased rigidity of the great vessels contributes to the rise in systolic pressure. There is a decline in the sensitivity of the baroreceptor reflex, but the contribution of this to the elevation of pressure has not be elucidated. Elderly patients with uncomplicated essential hypertension have a low cardiac output and high peripheral vascular resistance. The rise in blood pressure is associated with an increased cardiovascular morbidity and mortality even in the elderly hypertensives. The available data on the efficacy of hypotensive treatment in the elderly is scanty. There are no data proving that hypotensive therapy prolongs life. Controlled studies on the prevention of organ damage especially cerebrovascular accidents are inconclusive, showing either a significant decrease or no effect. Isolated reports illustrate, however, that drastic blood pressure reduction can provoke serious side effects, thus decreasing the quality of life. Hypotensive treatment is indicated in elderly hypertensive patients with hypertensive retinopathy grade III or IV, congestive heart failure or cerebral haemorrhage, in elderly patients with a markedly elevated diastolic blood pressure (greater than or equal to 120 mm Hg) and a trial of hypotensive therapy should be offered in milder forms of hypertension when it is accompanied by certain specific symptoms such as angina, headache and dyspnoe. The management of elderly hypertensive patients is more difficult than in the young. General measures are often not well accepted. The dose adjustment of the hypotensive agent is more critical and volume depletion or orthostatic hypotension are more likely to occur.