Short-term estrogen administration improves abnormal endothelial function in women with systemic sclerosis and Raynaud's phenomenon.

BACKGROUND: Morphologic changes of the vascular endothelium are common in patients with systemic sclerosis and Raynaud's phenomenon. The aim of this study was to evaluate the endothelium-dependent vasodilatation and endothelium-independent vasodilatation and to examine the effects of short-term estrogen administration on vascular responses in these patients. METHODS AND RESULTS: The study included 12 female patients with systemic sclerosis and Raynaud's phenomenon (aged 49+/-14 years) and 12 age- and sex-matched healthy control subjects. With the use of high-resolution ultrasound imaging, brachial artery diameter was measured at rest, during reactive hyperemia (endothelium-dependent response), and after administration of sublingual nitroglycerin (endothelium-independent dilatation). Intima-media thickness of the common carotid artery was also measured. Baseline diameter was similar in patients and control subjects; intima-media thickness was significantly higher in patients (0.83+/-0.3 vs 0.46+/-0.2 mm, P= .002) than in control subjects. Flow-mediated dilatation was reduced in patients (3.6%+/-7% vs 11.9%+/- 4.6%, P = .003); endothelium-independent dilatation also was reduced in patients with Raynaud's phenomenon (14%+/-7% vs 23%+/-6%, P= .003). Vascular responses in 10 patients were examined 15 minutes after administration of conjugated estrogens (25 mg intravenously); there was a significant increase of endothelium-dependent dilatation after estrogen administration (1.7%+/-4% to 6.3%+/-4%, P= .01), whereas endothelium-independent dilatation did not change (13.4%+/-8% to 15.5%+/-7%, not significant). CONCLUSIONS: Endothelium-dependent vasodilatation and endothelium-independent vasodilatation are impaired in patients with Raynaud's phenomenon secondary to systemic sclerosis, whereas intima-media thickness is increased. Short-term estrogen administration can improve endothelial dysfunction in this group of patients.

Effects of acute cigarette smoking on endothelium-dependent arterial dilatation in normal subjects.

The effects of acute cigarette smoking on endothelial function were evaluated in the brachial artery of 10 nonsmoking healthy subjects. Endothelial dysfunction observed after cigarette smoking is a phenomenon lasting at least 60 minutes and does not appear to be attenuated with repeat exposure.

Peripheral vascular endothelial dysfunction in patients with angina pectoris and normal coronary arteriograms.

OBJECTIVES: We sought to determine endothelium-dependent vasodilator function in the brachial artery of patients with microvascular angina pectoris. BACKGROUND: Previous studies suggest the presence of endothelial dysfunction of the coronary microcirculation in patients with microvascular angina pectoris. It is not known whether endothelial dysfunction in these patients is a generalized process or whether it is confined to the coronary microcirculation only. METHODS: In 11 women (mean [+/-SD] age 60.1 +/- 7.8 years) with microvascular angina (anginal pain, normal epicardial coronary arteries, positive exercise stress test), endothelium-dependent vasodilation was assessed in the brachial artery by measuring the change in brachial artery diameter in response to hyperemic flow. Results were compared with 11 age- and gender-matched patients with known three-vessel coronary artery disease and 11 age- and gender-matched healthy control subjects. In all subjects, the intima-media thickness (IMT) of the common carotid artery was also measured. RESULTS: Flow-mediated dilation (FMD) was comparable in patients with microvascular angina and coronary artery disease (1.9 +/- 2.5% vs. 3.3 +/- 3.3%, p = NS) but was significantly lower in patients with microvascular angina than in healthy control subjects (1.9 +/- 2.5% vs. 7.9 +/- 3%, p < 0.05). IMT was significantly lower in patients with microvascular angina than in those with coronary artery disease (0.64 +/- 0.08 vs. 1.0 +/- 0.28 mm, p < 0.05) and was comparable between patients with microvascular angina pectoris and healthy control subjects (0.64 +/- 0.08 vs. 0.56 +/- 0.14 mm, p = NS). IMT > or = 0.8 mm was observed in 1 of 11 patients with microvascular angina, 1 of 11 control subjects and 10 of 11 patients with coronary artery disease. CONCLUSIONS: These findings suggest that endothelial dysfunction in microvascular angina is a generalized process that also involves the peripheral conduit arteries and is similar to that observed in atherosclerotic disease. IMT could be helpful in discriminating patients with microvascular angina and atherosclerotic coronary artery disease.

Effect of acute cigarette smoking on endothelium-dependent brachial artery dilatation in healthy individuals.

The effect of short-term smoking on endothelium-dependent and endothelium-independent dilatation of the brachial artery was tested in 27 healthy volunteers using high-resolution ultrasound imaging. Short-term smoking led to a significant decrease in endothelium-dependent dilatation.

Effect of site and intensity of pacing on left ventricular performance.

The effect of pacing site and intensity on left ventricular performance is examined. The maximal value of left ventricular developed pressure (PD) and the peak (dp/dt) /P (Vpm) were followed in 11 anesthetized dogs. The following sites were paced: atrial (A), simultaneous atrial and right ventricular (RV), simultaneous atrial, right and left ventricular (RLV) and simultaneous atrial and left ventricular (LV)(, while varying the rate from sinus rate up to 350/min and the intensity from threshold up to 20-120 mA. When all 4 sites were paced in the same experiment, the A pacing resulted in the highest values of Vpm and PD while RV pacing resulted in the lowest values. The higher the pacing intensity the higher the Vpm and PD values tended to be. The strongest correlation coefficient was observed between Vpm and intensity on RV pacing while the same correlation on LV or Rv pacing and between PD and intensity on LV pacing were not significant at the 5% level. On RV pacing a low (les than 0.85) Vpm ratio (Vpm on RV pacing expressed over Vpm on A pacing at the same frequency and intensity) was associated with 65% of 129 pacing runs at a relatively low (less than 35 mA) intensity but with only 35% of 91 runs at a higher intensity (X2 = 19,20, p less than 0.001). The effect of pacing site and intensity on Vpm tended to be more pronounced at faster than at slower pacing frequencies.(ABSTRACT TRUNCATED AT 250 WORDS)