冠心病患者经皮冠状动脉腔内成形术后血浆内皮素改变及其…

经皮冠状动脉腔内成形术常导致冠状动脉收缩，其发生机制尚不明了。本研究对ＰＴＣＡ的１６例冠心病患者进行血浆内皮素水平，平均血压和心率的观察。结果表明，ＰＴＣＡ后股动脉血浆ＥＴ水平无明显改变，冠状窦血浆ＥＴ浓度明显升高，而平均血压和心率在ＰＴＣＡ前后均无明显改变。     

经皮腔内冠状动脉成形术前后血浆内皮素—1水平的动态观察

采用放射免疫分析法测定了１４例冠心病心绞痛患者经皮腔内冠状动脉成形术（ＰＴＣＡ）（８例）及单行冠状动脉造影术（ＣＡＧ）（６例）前后血浆内皮素—１（ＥＴ—ｌ）水平并与１０例正常人作对照观察。结果显示：ＣＡＧ及ＰＴＣＡ后对小时内血浆ＥＴ—１水平均未见显著升高（Ｐ＞０．０５）。提示，ＰＴＣＡ前后全身循环ＥＴ的血浆浓度改变不大。     

心脏收缩时间间期对经皮冠状动脉腔内成形术后晕厥心肌估价的探讨

动态观察１４例经皮冠状动脉腔内成形术（ＰＴＣＡ）病人手术前后心脏收缩时间间期（ＳＴＩ）变化，估价ＳＴＩ改变时判断晕厥心肌的价值。结果显示:ＰＴＣＡ后３～５ｄ，ＳＴＩ评价左心功能较为敏感的指标射血前时间／左室射血时间（ＰＥＰ／ＬＶＥＴ）比值，由０．３８６±０．６００增加至０．４６０±０．０７０；至７～８ｄ恢复至术前水平。与同期测定的超声心动图左室射血分数（ＬＶＥＦ）相比，变化趋势一致。提示ＰＴＣＡ后，系列测定ＳＴＩ，可动态反映左心功能变化。ＰＥＰ／ＬＶＥＴ比值改变可作为判断晕厥心肌恢复的指标之一。     

直接经皮冠状动脉腔内成形术与溶栓治疗急性心肌梗塞近期疗效分析

目的比较直接经皮冠状动脉腔内成形术（ＰＴＣＡ）与药物溶栓治疗急性心肌梗塞（ＡＭＩ）患者住院期间的临床效果。方法在１０９例ＡＭＩ患者中，４５例患者接受直接ＰＴＣＡ治疗，６４例患者接受药物溶栓治疗。结果溶栓组梗塞相关血管（ＩＲＡ）再通的患者有４８例，再通率为７５％；直接ＰＴＣＡ组ＩＲＡ成功开通的患者有４４例，成功率为９７．８％。住院期间左室射血分数（ＥＦ）溶栓组为５４．１±１３．２，直接ＰＴＣＡ组为６４．２±１０．１，差异有显著性（Ｐ＜０．０５）；病死率分别为６．３％和２．２％，两组间差异无显著性（Ｐ＞０．０５）。进一步分析溶栓再通组与直接ＰＴＣＡ成功组的临床疗效，前者因再闭塞或缺血发作行择期ＰＴＣＡ的比率明显高于直接ＰＴＣＡ组（２７．１％ｖｓ０；Ｐ＜０．０５），但直接ＰＴＣＡ组左室ＥＦ仍显著高于溶栓再通组（６４．８±９．８ｖｓ５５．９±１２．６Ｐ＜０．０５）。住院期间再发梗塞，心肌缺血事件和心力衰竭例数溶栓再通组都有增加的趋势，但差异无显著性（Ｐ＞０．０５）。结论直接ＰＴＣＡ与溶栓治疗ＡＭＩ患者，前者可使ＩＲＡ充分有效地开通，能更好地改善患者心功能     

充血性心衰患者血浆内皮素和一氧化氮变化的临床意义及培哚普利的干预作用

为了解充血性心衰（ＣＨＦ）时心钠素（ＡＮＦ），内皮素（ＥＴ）和一氧化氮（ＮＯ）变化的临床意义及培哚普利的于预作用，我们选择４０例临床确诊为ＣＨＦ的患者，并随机分为培哚普利治疗组和常规治疗组，放免法测定血浆ＡＮＦ，ＥＴ含量，比色法测定血浆ＮＯ含量，与正常对照组比较，并观察治疗前后上述指标的变化情况。结果ＣＨＦ患者的血浆ＡＮＦ，ＥＴ水平均显著高于对照组（Ｐ＜０．０１），ＮＯ明显低于对照组（Ｐ＜０．０５）。常规治疗组治疗前后上述指标无明显改变（Ｐ＞０．０５），培哚普利平均治疗８周后ＡＮＦ，ＥＴ显著下降（Ｐ＜０．００１）而ＮＯ显著上升（Ｐ＜０．０５），提示ＡＮＦ，ＥＴ和ＮＯ参与了ＣＨＦ的病理生理过程。培哚普利可以降低ＣＨＦ的治疗有益。     

老年人急性脑梗塞24小时内不同时点垂体－腺轴功能改变的研究

对６７例老年人急性脑梗塞患者发病后２４小时内分别对８时、１２时、１６时、２４时皮质醇（ＰＴＣ）、甲状腺功能、睾丸酮（Ｔ）、雌二醇（Ｅ_２）的血浆水平进行动态研究。结果：患病组４次检测的血浆水平除ＴＳＨ外，余均较对照组低（Ｐ＜０．０１），其中８时最高，２４时最低；Ｅ_２与血粘度、血脂的相关性明显（ｒ＝０．７８，Ｐ＜０．０１）。另外还发现腺垂体系统功能改变与脑梗塞的发病明显相关，当腺垂体系统激素分泌降低时发病人数增多，相反则减少，发病高峰为２４时至次日８时，这可能与ＰＴＣ、甲状腺功能中Ｔ_３、Ｔ_４、Ｔ的降低而Ｅ_２的升高致血粘度升高有关；还发现激素改变与梗塞部位有关，其中丘脑梗塞时激素的改变显著低于皮层及基底节区（Ｐ＜０．０５）。     

尿转铁蛋白排泄率测定对糖尿病肾病早期诊断的意义

应用免疫速率散射比浊法测定５２例健康人和７６例无临床蛋白尿的糖尿病患者２小时尿微量白蛋白（Ａｌｂ）和微量转铁蛋白（ＴＲＦ）的排泄率（ＡＥＲ和ＴＥＲ）。结果：１．糖尿病组ＡＥＲ和ＴＥＲ均明显高于正常对照组（Ｐ＜０．０１）。２．在糖尿病组中，３２．９％的患者ＡＥＲ升高，４３．４％的患者ＴＥＲ升高，两者有显著性差异（Ｐ＜０．０１）。ＴＥＲ和ＡＥＲ呈明显正相关（ｒ＝０．９３，Ｐ＜０．０１）。３．在ＡＥＲ升高和ＴＥＲ升高糖尿病组中，其血压分别稍高于ＡＥＲ正常糖尿病组和ＴＥＲ正常糖尿病组，差异有显著性意义（Ｐ＜０．０５），而空腹血糖水平无此变化（Ｐ＞０．０５）。与无视网膜病变组相比，有视网膜病变组ＡＥＲ、ＴＥＲ升高的阳性率增加，两者有显著性差异（Ｐ＜０．０５）。提示：ＴＥＲ做为糖尿病肾病早期诊断指标，可能与ＡＥＲ具有相同的意义，甚至较其敏感。     

闭塞性冠状动脉病变PTCA成功率及影响因素

目的探讨完全闭塞性和几乎完全闭塞性病变ＰＴＣＡ成功率及其影响因素。方法对３５例发生过心肌梗塞和２１例未发生心肌梗塞的完全或几乎完全闭塞性病变施行了ＰＴＣＡ。结果完全闭塞性病变心梗发生后１周内ＰＴＣＡ成功率为１００％,２周～３个月为６６．７％,３个月以后为４２．９％;无桥侧支的几乎完全闭塞性病变ＰＴＣＡ成功率为１００％,桥侧支丰富的几乎完全闭塞性病变ＰＴＣＡ成功率为６２．５％。结论心肌梗塞早期ＰＴＣＡ成功率明显高于心肌梗塞晚期ＰＴＣＡ成功率（Ｐ＜０．０５）,无桥侧支的几乎完全闭塞性病变ＰＴＣＡ成功率明显高于桥侧支丰富的几乎完全闭塞性病变的成功率（Ｐ＜０．０５）     

肝硬化患者血浆ET1,CGRP变化意义探讨

目的：为了解ＬＣ患者血浆ＥＴ，ＣＧＲＰ水平，探讨其临床意义，方法：采用放射免疫分析法检测健康成人及ＬＣ患者血浆ＥＴ，ＣＧＲＰ水平，结果：ＬＧ组血浆ＥＴ１明显高于对照组（Ｐ〈０．０１），ＣＧＲＰ明显低于对照组（Ｐ〈０．０１），ＬＣ组内ＥＴ１，ＣＧＲＰ水平与肝功分级，血浆蛋白及ＡＬＴ，ＡＳＴ值无明显相关性（Ｐ〉０．０５）。结论：作为血管活性物质ＥＴ与ＣＧＲＰ相互拮抗，调节门脉压力保持动态平衡。ＬＣ门脉     

高血压患者血浆和淋巴细胞中血管紧张素Ⅱ、内皮素和一氧化氮的变化及关系

分析一组高血压病患者血浆和淋巴细胞中血管紧张素Ⅱ（ＡｎｇⅡ）、内皮素（ＥＴ）和一氧化氮（ＮＯ）含量的变化及它们间的相互关系。方法高血压（ＥＨ）组３９例，正常对照（ＮＣ）组４１例，放射免疫分析法测定ＡｎｇⅡ、ＥＴ，高效液相色谱分析法测定ＮＯ。结果ＥＨ患者血浆和淋巴细胞中ＥＴ均高于ＮＣ组（Ｐ分别＜０．０５和＜０．０１），ＮＯ低于ＮＣ组（Ｐ分别＜０．０５和＜０．０１）。除血浆ＥＴ和ＮＯ外，各指标改变ＥＨⅡ期较Ⅰ期明显（Ｐ分别＜０．０５和＜０．０１）。逐步回归分析表明，ＥＨ组平均动脉压（ＭＡＰ）与血浆及淋巴细胞中ＡｎｇⅡ、ＥＴ呈正相关，与ＮＯ负相关（ｒ分别＝０．６７，０．８１，Ｐ均＜０．０１）；ＥＨ组血浆和淋巴细胞中ＮＯ与ＡｎｇⅡ、ＥＴ均呈负相关（ｒ分别＝－０．６５１，－０．７２５，Ｐ均＜０．０１）。结论淋巴细胞反映血管内皮细胞内分泌功能比血浆更为敏感，与ＭＡＰ相关性更好，ＡｎｇⅡ、ＥＴ和ＮＯ三者分泌失平衡，是ＥＨ发病的重要原因之一。     

PCI术对冠状动脉循环中肾上腺髓质素及内皮素的影响

目的 :探讨经皮腔内冠状动脉介入术 (PCI)对冠状动脉循环中肾上腺髓质素 (ADM)及内皮素 (ET 1)水平的影响。方法 :33例冠心病患者分别于冠状动脉造影前后即刻、球囊扩张后即刻、支架置入后即刻、术后 10min采集冠状静脉窦血 ,与此同时采集股动脉血 ,采用放免法测定ADM、ET 1的浓度。结果 :冠状动脉造影前后ADM及ET 1无明显变化 (P >0 0 5 ) ;球囊扩张后即刻冠状窦内ADM与ET 1明显升高 (P <0 0 1) ;支架后即刻ADM与ET 1有上升趋势 (P >0 0 5 ) ;术后 10minADM降至术前水平 ,ET 1仍明显高于造影前水平。结论 :冠状动脉造影对冠状动脉循环血管活性物质基本不影响 ;经皮腔内冠状动脉成形术 (PTCA)及支架术后冠状动脉循环中ADM与ET 1明显升高 ,可能与球囊损伤内皮、支架对管壁的机械压迫及刺激有关。二者可能参与了PTCA及支架术后急性闭塞、再狭窄的调节。     

Circulating immunoreactive endothelin in patients undergoing percutaneous transluminal coronary angioplasty

Circulating immunoreactive endothelin (ir-ET) in the coronary sinus (CS) and the femoral artery (Ao) was measured in patients who underwent percutaneous transluminal coronary angioplasty (PTCA). Plasma ir-ET level in the CS was significantly increased from 1.6 +/- 0.8 pg/mL to 2.0 +/- 1.0 pg/mL after PTCA (P less than .05). Plasma ir-ET level in the Ao tended to increase after PTCA, but it was not significant. Plasma ir-ET level in the CS was not related to the plasma thromboglobulin level, plasma thrombin-antithrombin complex level, mean blood pressure, or heart rate. These results suggest that the increase of plasma ir-ET level in the CS may be associated with the coronary endothelial injury by PTCA.     

Matrix metalloproteinase expression in the coronary circulation induced by coronary angioplasty

Recent studies have revealed that matrix metalloproteinases (MMPs) play an important role in cardiovascular remodeling by degrading the extracellular matrix. We investigated changes in the expression of MMPs due to percutaneous transluminal coronary angioplasty (PTCA). We studied 47 patients with ischemic heart disease who underwent elective PTCA on isolated stenotic lesion of left coronary arteries. Twelve patients received conventional balloon angioplasty, 14 percutaneous transluminal rotational atherectomy and 21 stent implantation. Blood samples were drawn from the coronary sinus immediately before and after, as well as 4 and 24 h, after PTCA. Plasma levels of MMP-1, MMP-2, tissue inhibitor of MMP (TIMP)-1 and TIMP-2 were measured by enzyme-linked immunosorbent assay. Plasma MMP-2 activity was determined with the digestion of a specific chromogenic peptide substrate. We could observe serial changes in plasma MMP-1 levels in the coronary circulation only in one patient, because MMP-1 levels were lower than the limit of detection in other patients. On the other hand, plasma MMP-2 levels in the coronary sinus were detectable in all subjects and increased significantly 4 and 24 h after PTCA. Plasma TIMP-1 levels also showed significant increases 4 and 24 h after PTCA, whereas TIMP-2 did not show significant changes. Plasma MMP-2/TIMP-2 ratio and MMP-2 activity in the coronary sinus showed significant increases 4 and 24 h after PTCA. A positive correlation was observed between MMP-2 levels in the coronary sinus 4 h after PTCA and late loss index 6 months after PTCA. MMP-2 levels in the coronary sinus blood were significantly higher in patients with late restenosis than in those without restenosis. PTCA induces increases in plasma MMP-2 levels and activity in the coronary circulation, which may contribute to vascular remodeling and late restenosis after PTCA.     

冠状动脉内磁化支架置入术后冠状静脉窦血中NO与ET-1水平的变化

目的 :观察冠心病患者冠状动脉内置入磁化支架后冠状静脉窦血中一氧化氮 （NO）与内皮素 - 1（ET- 1）水平的变化 ,探讨磁化支架防治冠状动脉再狭窄的机制。方法 :经皮腔内冠状动脉成形术及冠状动脉内支架置入术的冠心病患者随机分为磁化支架组 （2 3例 ）及非磁化支架对照组 （16例 ）。经股静脉将 6 F右冠状动脉造影导管置入冠状静脉窦采血 ,采用 Griess法及非平衡法分别测定冠状动脉内支架置入术前及术后 6 h内冠状静脉窦血中 NO及ET- 1的水平。结果 :磁化支架组术后 6 h冠状静脉窦血中 NO含量较对照组相比显著升高 （P<0 .0 1） ;磁化支架组ET- 1水平的改变 ,包括术后即刻降低 P<0 .0 1)与 6 h回升 （P<0 .0 1）都不如对照组明显 ,两组 ET- 1水平在 3h有显著性差异 （P<0 .0 5 ）。结论 :冠状动脉内磁化支架置入术后 NO升高与 ET- 1水平变化趋缓反映了靶区血管局部内皮细胞功能改善 ,磁化支架置入术后急性冠脉痉挛及远期冠脉再狭窄的发生率降低可能与此有关     

Endothelium dependent and independent responses in coronary artery disease measured at angioplasty.

OBJECTIVE--To investigate the effects of substance P and papaverine, two drugs that increase coronary blood flow by different mechanisms, on vasomotion in stenotic coronary arteries at percutaneous transluminal coronary angioplasty (PTCA). DESIGN--Coronary blood flow responses to substance P and papaverine were measured in stenotic coronary arteries at the time of PTCA with quantitative angiography and a Doppler flow probe. SETTING--A cardiothoracic referral centre. PATIENTS--15 patients undergoing elective PTCA of a discrete epicardial coronary artery stenosis. INTERVENTIONS--Pharmacological coronary flow reserve was determined with papaverine 5-10 minutes before and after successful PTCA. Endothelium dependent responses to 2 minute infusions of substance P (10-15 pmol.min-1) were assessed immediately before PTCA. MAIN OUTCOME MEASURES--Coronary blood flow responses and changes in epicardial coronary artery area at stenotic, proximal, and distal sites with papaverine and substance P. RESULTS--Stenotic sites dilated with papaverine before PTCA (17.7%(6.9%) (mean (SEM)) area increase, p < 0.05 v baseline). Substance P dilated stenotic sites (16.8%(5.7%) area increase, p < 0.05) and proximal (14.3%(5.4%), p < 0.05) and distal sites (41.7%(9.3%), p < 0.005). Coronary flow reserve increased but did not reach normal values after PTCA (2.3(0.4) before PTCA v 3.0(0.4) after PTCA, p < 0.05) and was associated with an increase in peak flow with papaverine. Angioplasty did not alter baseline flow. After PTCA papaverine caused significant vasoconstriction at the stenotic site (-13.6%(4.3%) area decrease, p < 0.05). There was a negative correlation (r = -0.68, p < 0.05) between the dilator response with papaverine before PTCA and the constrictor response after PTCA. CONCLUSIONS--Substance P causes endothelium dependent dilatation in atheromatous coronary arteries, even at sites of overt atheroma. The cause of the paradoxical constrictor response to papaverine after PTCA is uncertain, but unopposed flow mediated vasoconstriction (the myogenic response) after balloon induced endothelial denudation may be one of several contributory factors.     

Coronary artery vasoconstriction routinely occurs after percutaneous transluminal coronary angioplasty. A quantitative arteriographic analysis

To determine whether percutaneous transluminal coronary angioplasty (PTCA) increases coronary artery luminal dimensions by stretching and injuring ("paralyzing") the smooth muscle of the arterial wall, we prospectively analyzed spontaneous changes and then intracoronary nitroglycerin-induced changes in segmental coronary artery diameters during the first 30 minutes after uncomplicated single-vessel PTCA in 10 patients. Five additional patients received intravenous nitroglycerin throughout the procedure to determine whether nitroglycerin could prevent vasoconstriction after PTCA. All of the patients were maintained on oral doses of diltiazem and aspirin at the time of the study. Coronary arteriography was performed at 2, 5, 15, and 30 minutes after PTCA and then 3 minutes after 300 micrograms i.c. nitroglycerin. Quantitative measurements (computerized edge-detection) were performed at each time, in coronary segments centered in the dilated segment, distal to the dilated segment, and in a control vessel not manipulated with the balloon catheter or guidewire. Progressive vasoconstriction (defined as a loss of diameter that was reversed by intracoronary nitroglycerin) was observed after PTCA in the dilated and distal segments (10 of 10 patients) but not in the control segment. The vasoconstriction in the dilated segment at 30 minutes (mean, 30 +/- 4%) was highly statistically significant compared with vasoconstriction at 2 and 5 minutes after PTCA (p less than 0.001) and compared with the control segment at 30 minutes (p less than 0.005). There was no significant loss of diameter after PTCA in the dilated segment in the five patients who received intravenous nitroglycerin. In conclusion, 1) spontaneous coronary artery vasoconstriction after PTCA occurs routinely at and distal to the site of balloon dilatation despite pretreatment with aspirin and calcium channel blockers; 2) coronary artery vasoconstriction after PTCA is rapidly reversed by intracoronary nitroglycerin and can be prevented by the continuous administration of intravenous nitroglycerin during and after the procedure; 3) these results are incompatible with the hypothesis that PTCA improves coronary luminal dimensions by arterial "paralysis"; and 4) these findings have implications concerning the etiology and prophylaxis of abrupt vessel closure after PTCA.     

Tissue factor expression in coronary circulation as a prognostic factor for late restenosis after coronary angioplasty.

We investigated changes in blood coagulation in the coronary circulation after percutaneous transluminal coronary angioplasty (PTCA) and its clinical significance. We examined 43 patients with ischemic heart disease who underwent elective PTCA of isolated stenotic lesions in the left coronary artery. Ten patients underwent PTCA alone, 15 received percutaneous transluminal rotational atherectomy (PTRA) and 18 stent implantation. Blood samples were drawn from the coronary sinus before and immediately after PTCA, as well as 4 and 24 h later. Plasma levels of tissue factor (TF), thrombin-antithrombin III complex (TAT) and prothrombin fragment 1+2 (F 1+2) were measured by enzyme-linked immunosorbent assay. Follow-up coronary angiography was performed 6 months after PTCA. Minimal luminal diameter was assessed by quantitative coronary angiography to evaluate late loss index. TF, TAT and F 1+2 levels in the coronary sinus blood showed significant increases 24 h after PTCA. A significant positive correlation was found between changes in TF levels 24 h after PTCA and late loss index 6 months after the procedure. TF levels in the coronary sinus blood were significantly higher in patients with late restenosis than in those without restenosis. These results suggest that TF expression in the coronary circulation after PTCA is a prognostic factor for late restenosis.     

Release of endothelin 1 and angiotensin II induced by percutaneous transluminal coronary angioplasty.

Endothelial injury plays critical roles in acute and chronic complications after percutaneous transluminal coronary angioplasty (PTCA). We investigated coronary endothelial injury and the release of vasoactive substances induced by PTCA. We examined 44 patients with ischemic heart disease who underwent elective PTCA to isolated stenotic lesions in left coronary arteries. Eleven patients received balloon angioplasty (BA), 14 percutaneous transluminal rotational atherectomy (PTRA), and 19 stent implantation. Blood samples were drawn from the coronary sinus immediately before and after as well as 4 hr and 24 hr after PTCA. Plasma levels of endothelin (ET) 1, angiotensin (ANG) II, von Willebrand factor (vWF), and thrombomodulin (TM) were measured. Seven control subjects who underwent diagnostic coronary angiography (CAG) were used as controls. In all patients, ET-1 levels in the coronary sinus blood significantly increased immediately after PTCA. ANG II levels and vWF activity showed significant increases 4 hr after PTCA. Changes in levels of these markers were similar among the BA, PTRA, and stent groups. TM levels were elevated in all groups of patients, including those simply undergoing diagnostic CAG. Changes in ET-1, ANG II, and vWF levels in the coronary sinus reflect coronary endothelial injury induced by PTCA.     

Vasoconstrictor activity of coronary sinus plasma from patients with coronary artery disease

Vasoactive properties of plasma samples taken from the coronary sinus, a systemic artery and the superior vena cava of 13 patients with angiographically proven coronary artery disease and from 5 patients with normal coronary arteriograms were assayed in vitro by measurement of the changes in tension of rings of isolated canine coronary arteries. Addition of 1 ml samples of platelet-rich plasma from the coronary sinus of patients with coronary artery disease into a 20 ml organ bath induced an initial relaxation followed by sustained constriction in bioassay coronary artery rings with endothelium and only vasoconstriction in rings without endothelium. The vasoconstrictor activity of the coronary sinus plasma showed positive correlation with the severity and extent of coronary artery narrowing. Systemic arterial and venous plasma samples from patients with coronary artery disease and the coronary sinus plasma from patients with no coronary artery disease evoked only endothelium-dependent relaxations. These vasoactive properties of the various plasma samples were similar whether the samples were taken during rest or during supine bicycle exercise. The serotoninergic receptor antagonist methiothepin prevented the vasoconstriction induced by the coronary sinus plasma samples. These data demonstrate that the coronary sinus blood of patients with atheromatous coronary artery disease exhibits vasoconstrictor activity that may be associated with 5-hydroxytryptamine (serotonin), presumably released from platelets.     

经皮腔内冠状动脉成形术中缺血预适应现象及其对血浆内皮素水平的影响

为研究经皮腔内冠脉成形术（PTCA）中的缺血预适应（IP）现象及其对血浆内皮素（ET）水平的影响，对33例成功的进行了PTCA的患者进行分组研究。其中10例采用缺血预适应方法，即球囊首次扩张90秒至2分钟，继以3～5分钟再灌注（A组），其余23例为非缺血预适应组（B组）。观察所有患者术中心绞痛症状及体表心电图ST段变化，并分别于术前、术后即刻、15分钟、1、3和24小时从股动脉取血，放免法测定ET水平。结果示：A组第二次扩张时心绞痛症状及ST段偏移程度均较第一次扩张时显著减轻（P＜0．05）；B组两次扩张时心绞痛症状及ST段偏移程度均无明显改变。A组术后血浆ET呈升高趋势，但与术前比较无统计学意义（P＞0．05）；B组血浆ET水平术后即刻升高，3小时达高峰，峰值较术前增高113．9％（P＜0．01），术后24小时恢复术前水平。提示IP不仅使心肌缺血程度减轻，同时可减轻PTCA对血浆ET水平的影响。