Symptomatic postural hypotension in the elderly was driven by an orthostatic reduction or failure to rise in peripheral resistance in 83% of cases during postural stress.
Observational (n=45)
What is the haemodynamic mechanism underlying postural hypotension in the elderly during postural stress?
Postural hypotension in the elderly is primarily driven by a failure to increase peripheral resistance during postural stress, a mechanism that normalizes with appropriate medical management or withdrawal of offending drugs.
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.
Williams et al. (Tue,) conducted a observational in Postural hypotension (n=45). Symptomatic postural hypotension vs. Cardiovascular-normal elderly patients was evaluated on Orthostatic reduction or failure to rise of peripheral resistance. Symptomatic postural hypotension in the elderly was driven by an orthostatic reduction or failure to rise in peripheral resistance in 83% of cases during postural stress.