COMPARISON OF NONINVASIVE METHODS FOR THE ASSESSMENT OF HEMODYNAMIC DRUG EFFECTS IN HEALTHY MALE AND FEMALE VOLUNTEERS - SEX-DIFFERENCES INCARDIOVASCULAR RESPONSIVENESS

1 The study was performed to determine the sensitivity and short-term and day-today variability of a novel technique based on laser interfer ometry of ocular fundus pulsations and of non-invasive methods for the quantification of haemodynamic drug effects. An additional aim was to assess sex differences in haemodynamic responsiveness to cardiovascul ar drugs in male and female healthy volunteers. 2 Ten males and nine f emales (age range 20-33 years) were studied in a double-blind, randomi zed, cross-over trial. Simultaneous measurements from systemic haemody namics, laser interferometry of ocular fundus pulsations, systolic tim e intervals from mechanocardiography, a/b ratio from oxymetric fingerp lethysmography and Doppler sonography of the radial artery were used t o describe the haemodynamic effects of cumulative, stepwise increasing intravenous doses of phenylephrine, isoprenaline, sodium nitroprussid e and of placebo. 3 Laser interferometry detected the isoprenaline-eff ects at the lowest dose level of 0.1 mu g min-1 with a high signal-to- noise ratio. The reproducibility of measurements under baseline was hi gh, no changes were observed after systemically effective doses of phe nylephrine or sodium nitroprusside. Systolic time intervals were sensi tive and specific for isoprenaline-induced effects, PEP and QS(2c)-mea surements had high reproducibility. Fingerplethysmography proved a sen sitive measurement for the detection of the vasodilating effects of so dium nitroprusside, but was not specific, and showed low reproducibili ty. Measurements from Doppler sonography had lower reproducibility and sensitivity compared with the other applied methods. 4 There was a si gnificant sex difference for several of the haemodynamic parameters un der baseline conditions; however, the responsiveness to the drugs unde r study was not different, when drug effects were expressed as %-chang e from the baseline. 5 Laser interferometry is a valuable non-invasive , highly sensitive and specific approach for the detection of pulse pr essure changes. A battery of non-invasive tests appears useful for the characterization of cardiovascular drugs. Gender differences may not pose a relevant problem for the study of acute haemodynamic effects of cardiovascular drugs.