The impacts of the establishment of chest pain center on the door-to-balloon time in patients with ST-elevation myocardial infarction by different transfer ways to hospital / 中国介入心脏病学杂志

Objective This study intends to explore the impacts of the establishment of chest pain center(CPC) on the door-to-balloon(D-to-B) time in patients with ST-elevation myocardial infarction (STEMI) by different transfer ways to hospital. Methods A regular CPC and a regional cooperative network were established based on the pre-hospital transmitted real-time 12-lead electrocardiogram system. The STEMI patients were divided into the following three groups by the different transfer ways to hospital before and after the establishment of chest pain center:self-referral groups (group A1, n=52, and group A2, n=65), EMS (emergency medical service ) groups (group B1, n=31, and group B2, n=92) and transfer PCI groups (group C1, n=23, and group C2, n=552). The mean D-to-B time and the rate of D-to-B below 90 minutes were compared between before and after the establishment of CPC and the reasons of reperfusion delay were analyzed. Results There were no statistical differences of the average D-to-B time [(123±78) min vs.(140±123)min, P > 0.05] and the rate of D-to-B time below 90 min (44.2%vs. 46.2%) between group A1 and group A2. The average D-to-B time was significantly shortened in group B2 [(89±66)min] while compared with that in group B1 [(155±115)min, P<0.05] and the rate of D-to-B time below 90 min was remarkably elevated in group B2 compared with that of group B1 (69.6%vs. 32.3%, P<0.05). The average D-to-B time was significant shorter in group C2 than in group C1 [(77±43)min vs. (337±662)min, P<0.05] and the rate of D-to-B time below 90 min was remarkable higher in group C2 than in group C1 (75.7%vs. 21.7%, P<0.05). The longer D-to-B time in self-referral groups was mainly due to the delay of getting informed consent before PCI when occupied catheterization laboratory was the major cause of reperfusion delay in EMS groups and transfer PCI groups. Conclusions The establishment of CPC may significantly shorten the D-to-B time and increase the rate of D-to-B time below 90 min for these patients admitted by EMS and transferred from non-PCI hospitals. However, the pathway for the self-referral patients should be further modified.

Study of the pre-hospital diagnostic reliability of real-time tele-transmission of 12-lead electrocardiogram of patients with acute ST-segment elevated myocardial infarction / 中华急诊医学杂志

Objective To evaluate the pre-hospital diagnostic reliability of real-time tele-transmission of 12-lead electrocardiogram of patients with ST-segment elevated acute myocardial infarction (STEMI).Methods The 12-lead electrocardiogram was simultaneously recorded with real-time tele-transmission system and a conventional electrocardiograph in 40 STEMI cases.The width and amplitude of each wave,the deviated amplitude of ST-segment in the same leads were compared by t-test and rank-sum test.Results There were no statistical differences in the width and amplitude of P wave,QRS wave and t wave as well as the deviated altitude of ST-segment between the two separate electrocardiographs (P ＞0.05).There was a significant positive correlation between the two ECG devices in respect of ST-segment elevated altitude (r =0.912,P =0.000).The differential ability of ST-segment elevation between two separate ECG devices kept highly consistent (Kappa value:0.976).Conclusions Real-time tele-transmission of 12-lead electrocardiogram is reliable for the pre-hospital diagnosis of STEMI.

Dynamic changes in type I collagen, MMP-1 and TIMP-1 after angioplasty / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the dynamic changes of type I collagen, and the activity of metalloproteinases-1 (MMP-1) and tissue inhibitor of metalloproteinases-1 (TIMP-1) after angioplasty.</p><p><b>METHODS</b>The restenotic model of iliac arteries of domestic microswine was established with hypercholesterol feed plus two angioplasties. Angioplastied vessels were harvested at the end of 1, 2, 3 and 6 months after the second angioplasty. Immunohistochemistry, transmission electronic microscopy and image quantitative analysis techniques were employed to study neointimal proliferation, the phenotype of vascular smooth muscle cells (VSMC) and the expression of type I collagen, MMP-1 and TIMP-1.</p><p><b>RESULTS</b>The peak of vascular neointimal proliferation was at 3 months after angioplasty. The expression of type I collagen gradually increased from 1 to 6 months after angioplasty. For MMP-1, expression was lower in the early stage after angioplasty but increase to normal levels of control vessels at 6 months after angioplasty. Expression of TIMP-1 rapidly increased in the early phase after angioplasty, reached peak at 3 months and maintained the high level till 6 months after angioplasty. Meanwhile, the VSMC was predominantly the synthetic phenotype at the early stage and was transformed to the contractive phenotype at the late stage after angioplasty. The ratio of TIMP-1 and MMP-1 was positively related to the area of the neointima and the expression of type I collagen respectively (P < 0.01).</p><p><b>CONCLUSION</b>Type I collagen increased gradually after angioplasty, which might be determined by the ratio of TIMP-1/MMP-1 and also related to the phenotype of VSMC.</p>

Effect of Estrogen Replacement Therapy on the Serum Nitric Oxide and Endothelin-1 Level of Ovariectomized Rats / 中国医师杂志

Objective To investigate the effects of estrogen replacement therapy on the serum nitric oxide and endothelin-1 level of ovariectomized rat.Methods The ovariectomized animal model and estrogen replacement therapy rat were established,thirty female rats were randomly divided into three groups:group A,ovariectomy;group B,ovariectomy plus estrogen replacement therapy;group C,sham-ovariectomy.The rats were killed after two months.The serum nitric oxide and endothelin-1 level were determined.Results In group A,the serum nitric oxide level was lower as compared with group C,but the serum endothelin-1 level was higher than those in group C.In group B,the serum nitric oxide level was higher and the serum endothelin-1 level was lower than those in group A.Conclusions Estrogen could modulate the productions of the nitric oxide and the endothelin-1 in the vascular endotheliocytes and improve the function of the vascular endothelial cells,which may be a bases of the benificial effect of estrogen in the prevention of atherosclerosis.