Albertus J. Voogel

Reproducibility of twenty-four-hour finger arterial blood pressure, variability and systemic hemodynamics.

Objective At present, non-invasive continuous monitoring of finger arterial blood pressure by the volume-clamp technique is considered the best approach to obtain reliable assessments of beat-to-beat blood pressure. However, data on the reproducibility (accuracy and precision) of prolonged recordings and of the hemodynamics derived from wave-form analysis are not available. Design Ten patients with untreated essential hypertension and eight normotensive subjects were monitored by Portapres over 24 h in the hospital on two occasions with 1–4 weeks in-between. Physical and mental activities were standardized as far as possible to minimize intra- and intersubject biological variability. Stroke volume was obtained by the Modelflow method. Differences between the two recordings were computed separately for the day (0700 to 2300 h) and the night (2300 to 0700 h) and for all hours. Differences in stroke volume were calculated as percentage change from the first recording. Results Accuracy was good in both groups and bias was close to zero. Precision was also remarkable in the daytime, and at least as good as values reported in studies that used the standard intra-arterial recording. The SD of the differences in systolic and diastolic pressure in the hypertensives in the daytime were 6.6 and 4.7 mmHg, respectively. At night, precision was less good, possibly because of the 30 min finger-cuff switching: 12.5 and 6.5 mmHg for systolic and diastolic pressure, respectively. The average stroke volume did not change more than 8% at most between the first and the second recordings. Conclusion These results indicate that the Finapres and Portapres devices are a reliable substitute for intra-arterial recording, and are most useful instruments for the study of blood pressure regulation.

Feasibility of cognitive screening of patients with ischaemic stroke using the CAMCOG A hospital-based study

Brief screening tests would be convenient for the measurement of cognitive impairment in stroke patients. In these patients aphasia can interfere with test procedures. To evaluate the feasibility of examining cognitive functions in stroke patients we examined 129 patients with an ischaemic stroke using the CAMCOG, a standardised neuropsychological screening test, after an interval of at least 3 months. Most patients (88%) were able to complete the CAMCOG. Patients with severe aphasia were significantly more likely to have an abnormal CAMCOG score than patients without aphasia [relative risk (RR) 4.0, 95% confidence interval (CI) 2.8–5.8]. The group of patients with moderate aphasia was not at higher risk of having an abnormal CAMCOG score than patients without aphasia (RR 1.4, 95% CI 0.6–2.8). Looking for other factors that might correlate with the scores, logistic regression analysis revealed age as the only significant factor for the prediction of the CAMCOG score (odds ratio 4.0, 95% CI 1.2–13.2). We concluded that the CAMCOG can conveniently be used for screening cognitive functions in patients with cerebral infarcts, even if there is moderate aphasia.

Orthostatic Hypotension Due to Suppression of Vasomotor Outflow After Amphetamine Intoxication

Ten hours after ingestion of amphetamines, a previously healthy 17-year-old female adolescent experienced dizziness on standing. Examination revealed pronounced drowsiness and severe orthostatic hypotension. Assessment of arterial baroreflex function suggested that suppressed sympathetic vasomotor drive was the cause of the orthostatic hypotension. Within 3 days, the baroreflex failure resolved spontaneously. To our knowledge, suppressed vasomotor outflow after ingestion of amphetamines has been previously observed only in animal studies.

Effects of antihypertensive drugs on the circadian blood pressure profile.

We compared the effect of beta-blockers, angiotensin-converting enzyme (ACE) inhibitors, and calcium antagonists on the circadian blood pressure (BP) profile in essential hypertension. We reviewed all studies published between 1980 and August 1993 reporting the circadian efficacy of antihypertensive drugs and using ambulatory BP monitoring. In all, 815 patients with essential hypertension were assessed in 51 studies of eight different beta-blockers, six ACE inhibitors, and eight calcium antagonists. As main outcome measures, relative (percentage) BP reductions during the day and at night were compared between the three classes of antihypertensive drugs. Results were also separated for different dosing schemes (once and more than once daily). With all three classes of antihypertensive agents, the percentage night BP reduction was approximately 1-3% less as compared with percentage reductions during the day. Only for systolic BP (SBP) of the calcium antagonists administered once daily was this difference significant [2.2%, confidence interval (CI) 0.3-4.0%, p < 0.05], due to a higher statistical power in this group of agents. Our results show that beta-blockers, ACE inhibitors, and calcium antagonists are comparably effective during the day and at night, and no evidence indicates that either of the three agents is preferable to obtain the best possible antihypertensive effect at night.