Haemodynamic Response to Postural Stress in the Elderly With and Without Postural Hypotension

Abstract

The haemodynamic response to postural stress (60 degrees foot-down tilt) was measured by impedance cardiography in six elderly cardiovascular-normal patients and 39 with symptomatic postural hypotension (systolic blood pressure drop greater than or equal to 20 mmHg or more). In the normal elderly the mean increase in heart rate, fall in blood pressure and cardiac output, and rise in peripheral resistance was less than that described in younger subjects. The changes were at their maximum in 1 min, and there was little further change over the next 5 min. In those with postural hypotension, orthostatic reduction (or failure to rise) of the peripheral resistance was the mechanism in 83% of cases, whatever the cause, and the time course of the haemodynamic changes was the same in the majority as in the normals. Serial tests in patients whose postural hypotension was controlled (by cessation of causal drugs, often multiple, by fludrocortisone, or by dihydroergotamine) showed return to normal.

Short-term postural reflexes in diabetic patients with autonomic dysfunction

“…These authors suggested that the abnormal response was due to autonomic dysfunction, which we now confirm, as well as increased peripheral arterial rigidity [40]. Two further studies in elderly patients also support these findings [38,39]. Kassis using Doppler to measure cardiac output in congestive heart failure patients also reported increases with upright posture.…”

“…It would have been reasonable to expect the cardiac output to decrease in patients with autonomic dysfunction, particularly as blood pressure decreases and the mechanisms controlling the circulation are impaired. However, similar increases in cardiac output with an upright posture have been reported [38,39,40,41]. A group using impedance cardiography, reported similar increases in some elderly patients during 60°head-up tilting.…”

Aging and Postural Hypotension

“…Most often, 1 or 3 minutes is used. Studies using arterial catheters show that after an immediate rise and fall in blood pressure in the first few seconds, most subjects will have their lowest pressure at about 1 minute after standing 14,15 . It is also important to specify whether this time is measured from beginning to stand or after standing.…”

“…Williams et al 15 examined the hemodynamic response to postural stress by tilt‐table testing in six healthy elderly (aged 70‐86) and 39 elderly (age not specified) who had postural hypotension ≥ 20 mmHg decrease in systolic blood pressure on standing for 1 minute). The subjects with postural hypotension had a variety of etiologies including medications, Parkinson's disease, and neuropathy.…”

Calcium channel antagonists – pharmacological differences and their clinical relevance to elderly patients

“…Of all the factors that influence patient susceptibility to adverse drug reactions, multiple drug therapy has been most strongly and most consistently implicated. 30 The polypharmacy of old age, together with the impaired baroreceptor response to hypotensive drugs, which is exaggerated when several drugs are prescribed, 31 place the elderly at particular risk of postural hypotension with these drugs.…”