Haemodynamic response to head-up tilt in elderly hypertensives and diabetics.

To examine the haemodynamic mechanism associated with postural hypotension (PH) in elderly people, haemodynamic response to head-up tilt was studied in 14 elderly hypertensives and 13 elderly diabetics. Hypertensives and diabetics were divided into those with or without PH, defined as > or = 10 mmHg decline in mean blood pressure in response to head-up tilt. There was no significant change in cardiac output in hypertensives or diabetics with PH, whereas there was a significant increase during tilt in hypertensives without PH (p < 0.0001) and diabetics without PH (p = 0.0054). Hypertensives without PH showed a significant decrease in total peripheral resistance in response to head-up tilt (p = 0.0043). In hypertensives with PH and in both diabetic groups, there was no change in total peripheral resistance in response to head-up tilt. There was no difference in ejection fractions or heart rate responses between subjects with and without PH in either disease group. The difference in cardiac output change was not explained by myocardial changes observed at echocardiography nor by heart rate response nor by differences in total peripheral resistance. The results suggest that an increase in cardiac output in response to changing posture may be more important than vasoconstriction in protecting elderly subjects from PH.

The effect of calcium channel blocking on immune capacity of cardiovascular patients.

Calcium channel blocking drugs are widely used in the treatment of cardiovascular diseases. In vitro these drugs have been shown to block mitogen-induced lymphocyte proliferation. Their possible immunosuppressive effect has been tested especially in combination with cyclosporine A. In the present work, the effect of the calcium channel blocking drug verapamil on immune functions of cardiovascular patients was studied. The changes in leukocyte subpopulations, mitogenic responses and immunoglobulin production were determined during a three-month therapy. A significant increase in suppressor/cytotoxic cell number was detected and a decrease in the CD4/CD8 ratio, although the values were still within normal range. The responses to T and B cell mitogens remained unchanged. No significant decrease could be detected in immunoglobulin production either, despite minor changes in IgM. Our results indicate that the immunologic effects of verapamil at therapeutic doses are of little clinical significance.