Determination of systemic haemodynamic alterations induced by slow-release nifedipine in elderly hypertensive...

We evaluated the systemic haemodynamic alterations induced by slow-release nifedipine administered to elderly hypertensive patients, 20 mg twice daily by the oral route for 4 weeks. A non-invasive chest electrical bio-impedance method was used to detect changes in stroke volume and cardiac output. The random, double-blind, crossover study showed variations in measurements made in the supine and in the standing position: delta -18.0% (P < 0.001) and delta -14.9% (P < 0.001) for mean arterial pressure; delta -16.5% (P < 0.01) and delta -34.9% (P < 0.01) for total peripheral resistance; and delta +8.1% (P < 0.05) and delta +12.6% (P < 0.01) for heart rate, respectively. In contrast, cardiac output and stroke volume were the same when measured in the supine and standing positions both when compared with the placebo period and when compared with each other. We conclude that slow-release nifedipine is effective in reducing systemic blood pressure levels of elderly subjects and that this phenomenon occurs without reductions in cardiac output.