PubMed · 5656857
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M Allgöwer, C Burri. 1968. Shock-index.. https://pubmed.ncbi.nlm.nih.gov/5656857/
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BACKGROUND: Endothelin-1, a powerful mediator of vasoconstriction, is increased in patients with congestive heart failure and appears to be a prognostic marker that strongly is correlated with the severity of disease. However, little is known about the potential immediate beneficial effects of acute blockade of the endothelin system in patients with symptomatic left ventricular dysfunction. We assessed the hemodynamic effects and safety of tezosentan, an intravenous dual endothelin receptor antagonist, in patients with moderate to severe heart failure. METHODS AND RESULTS: This randomized placebo-controlled study evaluated the hemodynamic effects of 6-hour infusions of tezosentan at 5, 20, 50, and 100 mg/h compared with placebo in 61 patients with New York Heart Association class III to IV heart failure. Plasma endothelin-1 and tezosentan concentrations were also determined. Treatment with tezosentan caused a dose-dependent increase in cardiac index ranging from 24.4% to 49.9% versus 3.0% with placebo. Tezosentan also dose-dependently reduced pulmonary capillary wedge pressure and pulmonary and systemic vascular resistances, with no change in heart rate. No episodes of ventricular tachycardia or hypotension requiring drug termination were observed during tezosentan infusion. Tezosentan administration resulted in dose-related increased plasma endothelin-1 concentrations. CONCLUSIONS: The present study demonstrated that tezosentan can be safely administered to patients with moderate to severe heart failure and that by virtue of its ability to antagonize the effects of endothelin-1, it induced vasodilatory responses leading to a significant improvement in cardiac index. Further studies are under way to determine the clinical effects of tezosentan in the setting of acute heart failure.
BACKGROUND: Headache is usually associated with high blood pressure (BP) despite the lack of evidence of such an association in most observational studies. Ambulatory BP monitoring provides an opportunity to analyze this relation because it permits measurement of BP before, during, and after episodes of headache. METHODS: We evaluated 76 patients with mild hypertension who underwent clinical evaluation, ambulatory BP monitoring, and questioning about the occurrence of headache and its characteristics during monitoring. The 24-hour BP curves of patients with and without headache during monitoring were compared using analysis of variance for multiple factors and repeated measurements. Hourly averages of BP surrounding the episode and 24-hour mean BP of patients with headache were compared using paired sample t tests. RESULTS: Twenty-five participants (33%) experienced headache during monitoring. Their 24-hour BP curves did not differ from those of participants without headache. Mean 24-hour BP was not different from BP registered during the episode of headache (mean +/- SD systolic BP: 137.0 +/- 17.3 vs 139.4 +/- 21.1; P =.13; diastolic BP: 83.3 +/- 12.8 vs 85.0 +/- 18.2; P =.30). Blood pressure values registered during the episode of headache and in the hours before and after the episode were not different from each other. Analysis restricted to 8 patients with migrainelike headache showed a similar pattern. CONCLUSIONS: In patients with mild hypertension, there is no association between the occurrence of headache and variation of BP. Health professionals must discourage patients with hypertension from believing that they can rely on the presence of such a symptom to know about their BP levels.
BACKGROUND: Salt dependency of blood pressure (BP) characterizes most models of experimental hypertension in which endothelins play a significant vasoconstrictor role. Despite this, there are no data on the regulation of plasma endothelin by salt balance in human hypertension. METHODS AND RESULTS: Plasma endothelin was measured in 47 patients with essential hypertension. Endothelin, catecholamine, and plasma renin activity (PRA) responses to 24-hour sodium deprivation (decreasing Na) were assessed in 29 of these patients. Endothelin was higher in hypertensive patients (4.6+/-0.2 fmol/mL) than in 20 control subjects (3.3+/-0.3 fmol/mL, P:<0.002), was correlated with BP, and was negatively associated with PRA (P:<0.04). Salt-sensitive, salt-resistant, and indeterminate groups were defined by the tertiles of the t statistic for the difference in BP before and after decreasing Na. Systolic BP falls were -15+/-1, -2+/-2, and -9+/-1 mm Hg, respectively. PRA, its response to decreasing Na, and its level after decreasing Na were lowest (albeit nonsignificant) in salt-sensitive patients. Baseline catecholamine and endothelin levels did not differ among the groups. In response to decreasing Na, catecholamines increased more significantly in salt-sensitive patients (+2.4+/-0.9 nmol/L) than in the other groups (0.4+/-0.2 and 0.7+/-0.2 nmol/L for indeterminate and salt-resistant groups, respectively; P:<0.03), whereas endothelin increased in the salt-sensitive group (0.8+/-0.3 fmol/mL), decreased in the salt-resistant group (-0.4+/-0.3 fmol/mL), and sustained minimal change in the indeterminate group (0.2+/-0.3 fmol/mL) (P:<0.04). Thus, endothelin levels in the salt-depleted state were highest in salt-sensitive patients (5.2+/-0.4 fmol/mL) versus the other groups (3.4+/-0.4 and 4.4+/-0.4 fmol/mL for salt-resistant and indeterminate groups, respectively) (P:<0.02). Changes in endothelin during decreasing Na and levels after decreasing Na were correlated with changes in catecholamines (P:<0.02). CONCLUSIONS: -Our data suggest that salt-depleted salt-sensitive hypertensives with blunted renin responses exhibit enhanced catecholamine-stimulated endothelin levels and may therefore respond better than unselected patients with essential hypertension to endothelin receptor blockers.