首页 | 官方网站   微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   102篇
  免费   0篇
医药卫生   102篇
  2019年   7篇
  2018年   9篇
  2017年   7篇
  1985年   2篇
  1984年   15篇
  1983年   11篇
  1982年   12篇
  1981年   1篇
  1980年   7篇
  1979年   2篇
  1978年   5篇
  1977年   5篇
  1976年   3篇
  1975年   8篇
  1974年   3篇
  1973年   4篇
  1972年   1篇
排序方式: 共有102条查询结果,搜索用时 15 毫秒
1.
2.
The ability of exercise radionuclide ventriculography to detect multivessel coronary artery disease in patients who survived a single myocardial infarction was assessed. Seventy-four patients who had had myocardial infarction at least 8 weeks earlier underwent cardiac catheterization and exercise radionuclide ventriculography. Thirty-eight patients had had an inferior infarction: 25 with multivessel disease and 13 with single vessel disease of the right coronary artery. Thirty-six patients had had an anterior infarction: 26 with multivessel disease and 10 with single vessel disease of the left anterior descending coronary artery.

Among patients with anterior infarction there was no significant difference between patients with single vessel disease and patients with multivessel disease with regard to resting ejection fraction, exercise ejection fraction, and the mean change from rest to exercise. Patients with single vessel disease had a decrease in ejection fraction from rest to exercise of 2.2 ± 2.7% units (mean) ± standard error [SE]), compared with a decrease of 5.4 ±1.3% units in those with multivessel disease (p = not significant [NS]). Seventeen of 26 (65%) patients with multivessel disease and 6 of 10 (60%) with single vessel disease had a decrease in ejection fraction of at least 5 percentage units (p = NS).

In patients with inferior infarction there was no difference in the mean resting ejection fraction in those with single vessel disease (53 ± 2%) compared with those with multivessel disease (50 ±2%); however, the mean exercise ejection fraction in patients with single vessel disease (57 ± 3%) was significantly higher (p < 0.005) than that in patients with multivessel disease (45 ± 2%). Sixteen of the 25 patients with multivessel disease (64%) but only 1 patient with single vessel disease (7.7%) had a decrease in ejection fraction of at least 5 percentage units (p < 0.001).

A new wall motion abnormality developed in 8 patients with anterior infarction and 11 with inferior infarction with multivessel disease and none with single vessel disease. The sensitivity and specificity in predicting multivessel disease using the criteria of the development of a new wall motion abnormality or a decrease in ejection fraction with exercise of at least 5 percentage units were 80 and 92% for the patients with inferior infarction, but only 69 and 40% for the patients with anterior infarction.

These results suggest that exercise radionuclide angiography can be used to discriminate between single and multivessel disease after inferior myocardial infarction. For patients with anterior infarction, only a new abnormality in wall motion accurately predicts multivessel disease, but this occurred in only one third of such patients.  相似文献   

3.
Pulmonary varix regression after mitral valve replacement.   总被引:1,自引:0,他引:1  
Pulmonary varix is a rare finding; only 35 documented cases have been reported. The first case was described in 1843 as an icidental postmortem finding. The first clinical diagnosis was not made until 1951. In more than half of the 35 cases, the varix was present in the absence of congenital and acquired heart disease. Six patients have had concomitant mitral rheumatic heart disease. This communication describes the second patient with rheumatic mitral regurgitation in whom the pulmonary varix became radiographically invisible after prosthetic mitral valve replacement.  相似文献   
4.
Described here is a case of multiple myeloma in a patient with sickle cell anemia. Viscometric studies were made by comparing the patient's whole blood, plasma and washed red blood cells with those of a normal control subject and a patient with sickle cell anemia. Results showed that the increased viscosity of the patient's whole blood as compared with that of the control patient with sickle cell anemia was mainly due to erythrocytic Interaction with the circulating abnormal immunoglobulin. It is postulated that the increased frequency of vaso-occlusive crisis that occurred in our patient in the months before the diagnosis and treatment of multiple myeloma, was due to this cell-protein interaction with the resulting enhancement of whole blood viscosity and the sickling phenomena.  相似文献   
5.
Atrial pacing was compared with multistage treadmill exercise testing in 50 patients undergoing diagnostic cardiac catheterization to determine the diagnostic sensitivity of atrial pacing. Coronary artery disease was considered significant if luminal narrowing greater than 75 percent was present. Twenty-one subjects (Group I) had no significant coronary artery disease with vessel narrowing of less than 50 percent. Twelve (Group II) had single vessel disease and 17 (Group III) had disease of two or more vessels.The mean maximal heart rate during atrial pacing was 140/min and during exercise testing was 131/min. A positive atrial pacing test result was obtained in 5 percent of patients in Group I, 17 percent of patients in Group II and 24 percent of patients in Group III. A positive multistage treadmill exercise test result was obtained in 10 percent of patients in Group I, 67 percent of patients in Group II and 94 percent of patients in Group III. These differences are statistically significant (P < 0.001). The sensitivity of atrial pacing was 20 percent compared with 83 percent for multistage treadmill exercise testing. The specificity of atrial pacing was 95 percent compared with 90 percent for multistage treadmill exercise testing. Thus, atrial pacing is an insensitive test in the diagnosis of ischemic heart disease and does not improve the diagnostic value of multistage treadmill exercise testing.  相似文献   
6.

Context

Long-acting reversible contraception (LARC) is the most effective reversible method to prevent unplanned pregnancies. Variability in state-level policies and the high cost of LARC could create substantial inconsistencies in Medicaid coverage, despite federal guidance aimed at enhancing broad access. This study surveyed state Medicaid payment policies and outreach activities related to LARC to explore the scope of services covered.

Methods

Using publicly available information, we performed a content analysis of state Medicaid family planning and LARC payment policies. Purposeful sampling led to a selection of nine states with diverse geographic locations, political climates, Medicaid expansion status, and the number of women covered by Medicaid.

Results

All nine states' Medicaid programs covered some aspects of LARC. However, only a single state's payment structure incorporated all core aspects of high-quality LARC service delivery, including counseling, device, insertion, removal, and follow-up care. Most states did not explicitly address counseling, device removal, or follow-up care. Some states had strategies to enhance access, including policies to increase device reimbursement, stocking and delivery programs to remove cost barriers, and covering devices and insertion after an abortion.

Conclusions

Although Medicaid policy encourages LARC methods, state payment policies frequently fail to address key aspects of care, including counseling, follow-up care, and removal, resulting in highly variable state-level practices. Although some states include payment policy innovations to support LARC access, significant opportunities remain.  相似文献   
7.
8.
9.
Pressure gradient measurement across a stenosis is used during angiopiasty to aid catheter positioning and estimate dilatation efficacy. The angiopiasty catheter itself, however, further reduces lumen size, and therefore augments the transstenotic gradient. To more precisely define the catheter influence on gradient, we derived a theoretical expression relating the measured gradient with the angiopiasty catheter in situ to the “true” gradient; that is, the gradient in the absence of the angiopiasty catheter. We then tested this theoretical construct in a canine femoral artery angiopiasty model. Fifty-four measurements were performed using 23 separate, 3-mm-long, 40 to 70% stenoses. As predicted by the theoretic model, “true” gradient is compounded by the angiopiasty catheter principally as a function of the angiopiasty catheter diameter (Dc) and the stenosis diameter (Ds). The best-fit curve of data points relating “true” and compounded gradients to various Dc and Ds combinations can be expressed as: Measured GRADIENT = K × true gradient, where K = 0.25 (e)4.47 (Dc÷Ds and e = 2.718. Thus, the transstenotic gradient measured at angiopiasty overestimates “true” resting gradient in a predictable manner, which is dependent on the ratio of Dc to Ds.  相似文献   
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号