ISSN:0009-7322    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

The hypothesis that plasma chylomicrons in persons who ingest a cholesterol-rich diet are atherogenic is evaluated. Evidence is presented that in humans, and experimental animals, chylomicron remnants as well as low-density lipoproteins are taken up by arterial cells. In persons who do not have familial hyperlipoproteinemia, atherogenesis may occur during the postprandial period. Research directions that may contribute to the evaluation of chylomicron remnants as a risk factor for atherogenesis are discussed. Lipoprotein studies after administration of a test meal containing fat and cholesterol are urgently needed.

ISSN:0009-7322    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

Fasting plasma triglyceride, plasma cholesterol and high-density lipoprotein (HDL) cholesterol levels were studied for 190 white women, ages 21–39 years, who were classified according to their oral contraceptive (OC) usage patterns at two community surveys, 3 years apart. The mean level of fasting triglyceride was higher among current OC users (95 mg/100 ml) than among nonusers (73 mg/100 ml) (p= 0.002). After adjustment for the possible confounding effects of age, weight, current cigarette smoking and fasting glucose level, current OC users still had a mean plasma triglyceride level 19 mg/100 ml higher than that of nonusers (p= 0.007). Current OC users also appeared to have somewhat higher levels of total cholesterol which were of borderline significance in crude and adjusted analyses. There was a nonsignificant inverse relationship of OC use with HDL cholesterol levels. Past use did not affect these results, indicating that the OC-induced lipid changes were reversible.

ISSN:0009-7322    

出版商:OVID    

年代:1979

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

Studies of platelet and fibrinogen kinetics in 27 patients with hyperlipoproteinemia and 28 control subjects demonstrated shortened platelet survival and increased platelet turnover in seven patients with type III and 10 patients with type IV-V hyperlipoproteinemia (p< 0.01). There was no correlation between platelet survival time and specific lipid levels, vascular disease, sex or age. Platelet kinetics were not significantly altered from control values in eight patients with familial hypercholesterolemia. Platelet aggregation studies and fibrinogen kinetic measurements did not differ in any of the hyperlipoproteinemic groups of patients from those in control subjects. Despite significant changes in plasma lipids induced by clofibrate, platelet survival was significantly extended only in patients with type IV–V hyperlipoproteinemia (p< 0.05). These results are consistent with the hypothesis that atherogenesis in patients with types III–V hyperlipoproteinemia may be associated with a process of endothelial desquamation, and type Ila hyperlipoproteinemia may involve nondesquamating endothelial injury.

ISSN:0009-7322    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

We studied 11 patients with congestive heart failure and 10 normal volunteers for in vivo platelet aggregate formation activity. The patients with heart failure had significantly (p< 0.01) more circulating platelet aggregates than the normal volunteers. During sodium nitroprusside infusion, the number of circulating platelet aggregates declined to normal levels and in vitro platelet aggregation responses to epinephrine and adenosine diphosphate were also suppressed significantly (p< 0.01). This was associated with a 30% decline in systemic vascular resistance and a 28% increase in cardiac output. In other in vitro experiments, sodium nitroprusside was found to have direct, dose-related platelet aggregation inhibitory actions. This study suggests that an increase in vascular resistance in certain heart failure patients may in part be related to an increase in circulating platelet aggregates. Direct inhibition of platelet aggregation by sodium nitroprusside may be a mechanism of its beneficial effects in heart failure.

ISSN:0009-7322    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

Ten consecutive hospitalized patients with uncontrolled variant angina were studied to evaluate the efficacy of nifedipine and perhexiline maleate treatment and to determine if the results of incremental ergonovine testing during treatment predicted the short-term clinical response. During a mean control period of 5.2 days without treatment other than nitroglycerin, 3.9 ± 4.7 (mean ± SD) episodes of variant angina occurred per day. During the subsequent treatment period with nifedipine 20 mg every 6 hours, only 0.09 ± episodes/day occurred (p< 0.02 vs control) and seven patients had no angina. During perhexiline treatment (400 mg twice daily), 2.3 ± 3.2 attacks/day were recorded; this was not significantly different than during control period.Without treatment all 10 patients had positive ergonovine tests at doses ranging from 0.025–0.3 mg. During nifedipine treatment nine of the 10 tests became negative at doses as large as 0.4 mg (p< 0.0001). The results of ergonovine testing during perhexiline treatment did not differ significantly from the control period. Overall, 11 of the 12 ergonovine tests positive at 0.1 mg or less occurred during observation periods with more than episode/day of variant angina, and all 16 negative tests, or tests positive only at 0.2 mg or more, occurred during periods with less than one episode/day of variant angina.We conclude that the results of ergonovine testing during treatment correlate with the short-term clinical response to therapy. Although the effect of chronic treatment with calcium antagonists on the natural evolution of this syndrome is unknown, nifedipine rapidly and effectively controls the acute clinical manifestation of variant angina

ISSN:0009-7322    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

To study the influence of left ventricular (LV) late diastolic filling on the A wave of the LV pressure, simultaneously recorded echocardiographic LV dimensions and high-fidelity LV pressure measurements were taken in 24 patients. Group I comprised eight patients without LV hypertrophy (LVH) and LV end-diastolic pressure (LVEDP) ≤ 13 mm Hg. Group 2 comprised 16 patients with LVH secondary to aortic stenosis, idiopathic hypertrophic subaortic stenosis, or hypertension and increased LVEDP. Patients in group 2 had significantly thicker left ventricles, decreased mitral E-to-F slopes, and larger A waves in the LV pressure curve. On the basis of end-diastolic chamber stiffness, we divided group 2 into two populations: 12 patients (group 2A) with end-diastolic chamber stiffness similar to that in group 1, and four patients (group 2B) with markedly elevated end-diastolic chamber stiffness. Patients in group 2A had a larger atrial contribution to LV filling than those with markedly abnormal stiffness (group 2B). Therefore, in LVH an increased A wave in the LV pressure may be related to either elevated end-diastolic chamber stiffness or augmented left atrial volume transport.

ISSN:0009-7322    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

The effect of exercise-induced myocardial ischemia on cardiopulmonary blood volume was evaluated in patients with coronary artery disease during upright exercise stress testing. Regional pulmonary and cardiac blood volumes were monitored with a multicrystal positron camera positioned over the chest during maximal exercise on a bicycle ergometer. Inhaled carbon monoxide (< 10 ppm) labeled with cyclotronproduced carbon-il (11C) (half-life 20.3 minutes) was used to label the blood with11C-carboxyhemoglobin. Regional11C activity was measured over the heart and lungs during rest, exercise and recovery periods, and blood volume was calculated from regional11C activity compared with the specific activity of a reference venous blood specimen. For patients developing angina pectoris and electrocardiographic ST-segment depression (ischemic group, n = 9), blood volume increased 18.7 ± 6.3% (SEM) (p< 0.01) over the upper lung fields and 15.4 ± 6.8% (p< 0.05) over the lower lung fields at peak exercise. Conversely, for patients without angina or ST-segment depression at peak exercise (nonischemic group, n = 7), the regional pulmonary blood volume was unchanged over both upper and lower lung fields. The cardiac blood volume rose 6.1 ± 2.6% (p< 0.05) for the former group of patients and declined 10.6 ± 5.7% (p< 0.05) for the latter group at peak exercise. Coronary arteriography revealed double- or triple-vessel coronary disease in all patients in the ischemic group and normal coronary arteries or single-vessel disease in the nonischemic group. These data indicate that an ischemic response to exercise stress testing is associated with a transient rise in pulmonary and cardiac blood volume, which may be due to ischemia-induced left ventricular dysfunction.

ISSN:0009-7322    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

Left ventricular asynergy associated with acute myocardial infarction was evaluated by crosssectional echocardiography. Patients with acute infarction were studied within 48 hours of admission, and a segmental analysis of left ventricular wall motion was performed using nine segments obtained by short- and long-axis recordings of the left ventricle. By this segmental approach, analysis of wall motion in the entire left ventricle was possible. Complete studies were recorded in 37 of 44 original patients. Segmental wall motion abnormalities were recorded and localized in each of the 37 study patients. Asynergy was detected in 142 segments, and 29 patients had multiple segment involvement. Asynergy was most common in the apical segments of the left ventricle, but the cross-sectional scans permitted detection of asynergy in all segments. Correlation between the ECG and the cross-sectional echocardiogram revealed that 19 of 20 patients with inferior infarction had asynergy in posterior segments, 14 of 14 patients with anterior infarction had asynergy in anterior segments, and three of three patients with anteroinferior infarction had asynergy both anterior and posterior segments. In addition, the location of segmental asynergy followed specific patterns for each ECG subgroup of infarction. In four patients with postmortem examination, 21 of 22 segments that had asynergy by cross-sectional echocardiography also had pathologic evidence of infarction. Therefore, the cross-sectional echocardiogram provides a reliable method for detecting the presence and location of regional asynergy associated with acute myocardial infarction.

ISSN:0009-7322    

出版商:OVID    

年代:1979

数据来源: OVID