急性缺血性心肌损伤患者肌钙蛋白T检测的临床意义

目的 :为了早期、准确地判定急性缺血性心肌损伤程度。方法 :采用酶联免疫吸附方法 ,对 41例急性心肌梗塞患者、 38例心绞痛 (AP)疑有微小心肌损伤 (MMD)患者以及 40例健康 (HP)人进行心脏肌钙蛋白 T(c Tn T)测定 ,同时与 CK和CK— MB两项酶学指标相比较。结果 :AMI组 ,c Tn T、CK及 CK— MB三者之间的异常率无明显差别 (异常率 97%～ 10 0 % ) ;而AP组 ,c Tn T的异常率为 44 .7% ,明显高于 CK异常率的 7.9%和 CK— MB异常率的 13.2 %。与健康组相比 ,AP组的 c Tn T测定的水平明显高于对照组水平 (P<0 .0 1)。结论 :对于不同程度的急性缺血性心肌损伤的诊断 ,c Tn T较 CK及 CK— MB,具有更高的灵敏度及特异性。     

心肌缺血预适应对急性心肌梗死患者临床及近期预后的影响

目的 对初次急性心肌梗死（ＡＭＩ）发生前４８ｈ有无发作过心绞痛的患者的临床及近期预后进行评价。方法 ７４例初次ＡＭＩ的患者,接受住院常规治疗,按梗死前４８ｈ有无心胶痛分为有ＩＰ组（ｎ－３６）、无ＩＰ组（ｎ＝３８）,两组基本临床情况相似。结果有ＩＰ组较无ＩＰ组心肌梗死范围小（Ｐ〈０．０１）,心肌酶峰值低（Ｐ〈０．０１）,恶性心律失常、心力衰竭、心源性休克发生率及病死率均明显降低（Ｐ〈０．０５）。结     

Decreased interstitial glucose and transmural gradient in lactate during ischemia

Summary The purpose of this investigation was to assess the effects of ischemia and reperfusion on the transmural levels of glucose and lactate in the interstitium in 11 open-chest swine. Microdialysis probes were used to estimate changes in interstitial metabolities across the ventricular wall. Probes were placed in the subepicardium and the subendocardium of the left anterior descending (LAD) coronary artery perfusion bed and in the midmyocardium of the circumflex (CFX) perfusion bed. The LAD coronary artery was cannulated and perfused with blood from the femoral artery through an extracorporal perfusion circuit. Ischemia was induced in the LAD perfusion bed by reducing the flow of the LAD perfusion pump by 60% for 50 min, and was followed by 30 min of reperfusion. Regional myocardial blood flow was assessed with fluorescent microspheres. Ischemia resulted in a transmural gradient in blood flow, with the most severe reduction in flow occurring in the subendocardium (p<0.05). We found a significant reduction in interstitial glucose in both the LAD subepicardium (1.26±0.24 mM) (p=0.0009) and subendocardium (0.89±0.21 mM) (p=0.0001) during ischemia compared to the aerobic (non-ischemic) period (1.97±0.25 mM, 2.03±0.29 mM for the subepicardium and subendocardium, respectively). This coincided with a significant reduction in glucose delivery (LAD pump flow^* arterial glucose) to the LAD perfusion bed during ischemia (54.5±8.5 mol/min) compared to aerobic values (182.1±25.3 mol/min) (p<0.05). Interstitial lactate levels were significantly increased during ischemia in the LAD subendocardium (3.39±0.46 mM) compared to the aerobic values (1.73±0.46 mM) (p<0.0029). A transmural gradient in interstitial lactate levels was observed during ischemia: this gradient was not seen during the aerobic period and was negated upon reperfusion. In conclusion, ischemia resulted in a decrease in interstitial glucose in both the LAD subepicardium and subendocardium, and an increase in interstitial lactate in the LAD subendocardium. Further, a transmural gradient in interstitial lactate levels was observed during ischemia, with the highest lactate values appearing in the subendocardium.     

Release of chemoattractants and neutrophil activation in acute myocardial infarction immediately after successful recanalization of the infarct-related vessel by angioplasty

The study investigated inflamatory responses in evolving myocardialinfarction. Fifteen patients with acute myocardial infarction,who had undergone balloon recanalization of the infarct-relatedcoronary artery within 4 h after onset of symptoms, were examined.Blood samples were obtained through the guiding catheter andfrom the pulmonary artery before and immediately after successfulrecanalization. After recanalization, plas from the pulmonaryartery was 47% (quartiles: l9%, 78; P =0·001) more chemotacticto neutrophils from normal donors than before recanalization.Furthermore, significant changes in neutrophil function werefound in the pulmonary artery. Compared to the values beforerecanalization, the nitroblue tetrazolium score rose by 31%(quartiles: 4%, 37% P=0·003), FMLP-stimulated superoxideanion production by 10% (quartiles: 0%, 39% P=0·020),and chemotaxis by 46% (quartiles: 0%, 81%, P=0·011),while neutrophil filterability decreased by 28% (quartiles:15%, 47%; P=0·010). No significant changes in neutrophilparameters were found in the arterial blood The study indicatesthat chemoattractants are released in the early reperfusionperiod of evolving myocardial infarction. These chemoattractantsmay act as inflammatory mediators causing neutrophil activation.     

Myocardial infarction in an adult resulting from coronary ancurysms previously documented in childhood after an acute episode of Kawasaki's disease

Coronary aneurysms resulting from a previous episode of Kawasaki'sdisease are considered an important cause of myocardial infarctionin children. A case of a 19-year-old man presenting with anacute myocardial infarction associated with coronary aneurysmsis described. These coronary lesions were previously evaluatedangiographically and echocardiographically at the age of 13years, 5 months after the acute episode of a Kawasaki's disease.     

Reverse redistribution: fact or fiction?

It has been well documented that it is not uncommon for a thallium-201 perfusion defect to develop or become more evident on delayed exercise thallium scintigraphic imaging, as compared with the initial image immediately following stress. The pathophysiology and clinical significance of the phenomenon are currently unclear. Literature on this subject is reviewed, and it is concluded that reverse redistribution of ²⁰¹Tl in the post-myocardial infarction patient is indeed a fact. In this context it represents a low-risk condition and may imply successful thrombolysis, patent infarct-related coronary artery, improved wall motion at the infarct site and retained myocardial viability in that segment. Correspondence to: A. Labiri     

胺碘酮抑制缺血浦肯野纤维起搏离子流

目的观察正常及模拟“缺血”时胺碘酮对绵羊心室浦肯野纤维起搏离子流（Ｉｆ）的影响。方法双微电极电压钳制术,使膜电位过度极化以激活Ｉｆ。结果胺碘酮１×１０－５ｍｏｌ／Ｌ在正常台氏液中显著降低浦肯野纤维Ｉｆ幅值;模拟“缺血”也使Ｉｆ幅值降低,在此基础上,胺碘酮使Ｉｆ幅值进一步减小,加剧了“缺血”对Ｉｆ离子流的抑制作用。结论提示胺碘酮能抑制心肌缺血时心室正常自律性活动。     

Safety of modern oral contraception: the options for women: lessons to be learned

The relatively short history of hormonal contraception has been marked by a series of 'pill scares', all of which--after creating panic among users--were proven to be unfounded in terms of public health impact. The latest pill scare, provoked by regulatory action in the United Kingdom and the Federal Republic of Germany in response to the publication of a series of articles indicating a doubling of risk of deep venous thrombosis in users of oral contraceptives containing third-generation progestins, seems finally settled: both the British and the German Drug Regulatory Authorities have now reverted their verdict. The damage unfortunately stays: hundreds of thousands of women have been compelled to abandon the pill of their choice, often deciding to drop contraception altogether, thereby exposing themselves to unwanted pregnancy and--in a number of cases--to pregnancy termination. This latest episode should be turned into something positive: we need to learn that, in the case of drugs in widespread use, before restrictive action is taken--and except for very rare and specific instances--the scientific community must carry out an exhaustive debate on the reality and importance of the observed effects. Although the public should, in each instance, be properly informed, it is only after this process has been completed that restrictive action should be taken. It is hoped that, after this last episode, all concerned have learned this simple principle and will accept being guided by it from now on.     

血管紧张素Ⅱ Ⅰ型受体拮抗剂氯沙坦对急性心肌梗死的血流动力学效应

为观察口服氯沙坦(25mg,50mg)对急性心肌梗死患者的血流动力学效应,对10例急性心肌梗死患者放置漂浮导管,测量用药前及用药30min,1,2,3,4,6,9h时,收缩压(SBP)、舒张压(DBP)、平均动脉血压(MAP)、心率(HR)、外周血管阻力(SVR)、耗氧指数、心指数(CI)、肺毛压(PCWP)、左室每搏作功指数(LVSWI)、右房压(RAO)的变化。结果表明。服药后4h作用最明显,SBP、DBP、MAP、SVR、耗氧指数分别较用药前下降12％,11％,13％．14％和15％,25mg较50mg作用明显;CI轻度增加;HR、PCWP、RAP、LVSWI无明显变化。提示急性心机梗死患者口服氯沙坦产生外周阻力及心肌耗氧量下降,心指数增加等有益的血流动力学效应。氯沙坦25mg较50mg效果更明显。下壁心肌梗死早期应用需慎重。     

心肌梗死患者左室舒张功能评价方法的研究

探讨心肌梗死（ＭＩ）患者左室舒张功能的评价方法及临床应用。方法：采用脉冲多普勒超声心动 图技术检测５０例正常人和５０例ＭＩ患者的左房收缩时间间期（ＬＡＳＴＩ）。包括左房射血前期（ＡＰＥＰ）、校正心房射血 前期（ＡＰＥＰＣ）和左房射血期（ＡＥＴ）;肺静脉Ｓ峰、Ｄ峰、Ａ峰;二尖瓣血流Ｅ峰、Ａ峰及Ｅ／Ａ比值。ＭＩ组给予抗舒张 障碍治疗３周后再测量各项指标。结果：ＭＩ组的ＡＰＥＰ、ＡＰＥＰＣ缩短,ＡＥＴ延长;肺静脉Ｓ峰、Ａ峰增大,Ｄ峰减小; 二尖瓣Ｅ峰减小,Ａ峰增大（Ｐ＜０．０１）。ＭＩ组治疗３周后各项指标明显改善（Ｐ＜０．０１）。结论：综合多指标分析能 提高左室舒张功能评价的准确性。