大鼠股动脉缺血预适应对缺血再灌注心律失常的延迟性保护作用

对大鼠股动脉缺血预适应（ＦＩＰ）对缺血再灌注心律失常的延迟性保护作用进行了观察。结果：ＦＩＰ组缺血期室速（ＶＴ）、室颤（ＶＦ）的发生次数和累计持续时间较对照组（ＮＩＰ组）明显减少或缩短（Ｐ＜０．０１），再灌注性心律失常２组间差异不显著，动物死亡率（２０％）较ＮＩＰ组（５０％）降低，但无统计学意义（Ｐ＞０．０５）；ＦＩＰ２４ｈ组再灌注ＶＴ、ＶＦ较ＮＩＰ组明显减少，动物死亡率为０％，与ＮＩＰ组比较有显著性差异（Ｐ＜０．０５）。提示：大鼠ＦＩＰ对心肌缺血再灌注心律失常有明显的保护作用。延迟保护作用较早期保护效应更强，明显减少致命性再灌注ＶＴ、ＶＦ的发生，使动物存活率提高     

缺血预处理抑制缺血再灌注所致兔在体心肌细胞凋亡

目的：为探讨缺血预处理对缺血再灌注过程中心肌细胞凋亡的影响。方法：将24只新西兰白兔制成在体心肌缺血／再灌注模型,并随机分成假手术对照组（P组）,缺血／再灌注对照组（IR组）,缺血预处理组（IP组）,结果：IP组心肌梗死面积与缺血面积的比率比IR组显著减少（P＜0．05）;凋亡指数IP组亦比IR组小（P＜0．01）,IR组心肌DNA Ladder形成明显,IP组DNA Ladder模糊不清,结论：缺血预处理对缺血／再灌注损伤中心肌细胞凋亡具有抑制作用。     

The prevalence and outcome of ventricular arrhythmias in acute myocardial infarction

One hundred and seventy-two consecutive cases of acute myocardial infarction (MI) admitted to a coronary care unit were studied with regard to ventricular arrhythmias - pre-mature ventricular contractions (PVC), ventricular tachycardia (VT) and ventricular fibrillation (VF). Sixty-seven (39%) patients had ventricular arrhythmias (PCC-VT-VF), of whom 17 (9.8%) had VT and 11 (6.4%) VF. VT and VF, but not total arrhythmias, were more common in anterior infarctions. Fifty-six out of 67 (83.5%) of these patients arrived at Accident & Emergency (A&E) within the first six hours of onset of chest pain. Ten out of 11 (91 %) patients who had VF did so in the first six hours. PVCs were poor predictors of the occurrence of VF (positive predictive value 5.9%). Forty-three patients (84%) who had PVCs did not develop any further arrhythmias. Spontaneous heart rate had no influence on the occurrence of ventricular arrhythmias. Frequent PVCs were more commonly associated with progression to VT and VF. In 30 cases (88%) lignocaine was effective. There was no death due to VT/VF and all responded to drugs and/or cardioversion.     

Naloxone对兔急性心肌缺血心功能的影响

目的　探讨纳洛酮对急性心肌缺血心功能及血流动力学的影响。方法　结扎兔冠状动脉左室支复制急性心肌缺血模型 ,观察纳洛酮对左室收缩期峰压 (LVSP)、左室舒张末期压 (LVEDP)、血压、心率等参数的影响。结果　冠状动脉结扎前 5min及结扎后 2h纳洛酮组和对照心率、平均动脉压、LVSP、LVED分别为 2 38± 2 8bpm ,194±37bpm ;12 .5 33± 2 .5 33kPa ,10 .133± 2 .80 0kPa ;14.40 0± 3 .46 7kPa ;11.2 0 0± 4.933kPa ;1.2 37± 0 .32 0kPa ;1.80 0±0 .40 0kPa。两组相比差异显著 ,P值均 <0 .0 5。结论　纳洛酮对急性缺血心肌的心功能及血流动力学有明显的改善作用。     

自然呼吸条件下α-受体阻断剂对猪缺血性心律失常的影响

目的　研究在自然呼吸条件下α -肾上腺素受体阻断剂对猪的心肌缺血性心律失常的作用。方法　把猪开胸暴露心脏 ,但不损伤胸膜腔 ,仍维持自然呼吸。结果　α-受体阻断剂育亨宾 (yohimbin)可显著增加室性早搏的次数 (P <0 .0 1) ,但对室性纤颤出现的百分率无影响。然而非特异性α -受体阻断剂酚妥拉明显著地减少室性早搏的次数 (P <0 .0 1) ,但它不影响室性纤颤与室性心动过速出现的频率。结论　α-肾上腺素能机制对猪的心肌缺血性心律失常的发生不起重要作用。     

七氟醚预处理对缺血／再灌注心肌的保护作用

To observe the myocardial protective effects of sevoflurane pretreatment on ischemia-reperfusion injury, forty eight rabbits were divided into six groups randomly: control group, ischemia-preconditioning group, sevoflurane preconditioning group, ischemia preconditioning plus glyburide group, sevoflurane preconditioning plus glyburide group, glyburide group, each group subjected to three hours of left anterion descending coronary artery occlusion followed by three hours of reperfusion. Infarct size and area at risk were defined by staining. Infarct size [expressed as a percentage of the area at risk (IS:AR)] was (60.8 +/- 10.8)% in controls, and reduced to (33.1 +/- 4.9)% and (30.9 +/- 6.8)% respectively in ischemic preconditioning groups and sevoflurane preconditioning groups. Glyburide pretreatment eliminated the preconditioning effects of ischemia and sevoflurane [IS:AR = (59.3 +/- 11.2)% and (56.6 +/- 11.9)%, respectively; not significant]. Glyburide alone did not increase infarct size [IS:AR = (63.2 +/- 12.5)%, not significant]. It suggests that sevoflurane pretreatment protects the rabbit heart subjected to three hours of coronary occlusion from infarction.     

心电图QT变量对VT VF及心性猝死的预测价值

目的 探讨QT变量对室性心动过速（VT）、心室颤动（VF）及／或心性猝死的预测价值。方法 将538例AMI、急性心肌缺血患者的心电图进行分组、分类,对心电图QT变量进行测量、统计分析。结果 QTc、JTc、QT／TQ延长者,VT、VF及／或心性猝死的发生率明显大于QTc、JTc、QT／TQ值正常者（P＜0．05、＜0．01）;VT、 VF及／或心性猝死QTd、JTd、QTcd明显大于无VT、VF及／或心性猝死者（P＜0．05、＜0．01）。结论 QT变量的增大（示心室复极异常）对预测AMI、急性心肌缺血发生VT、VF及／或心性猝死有重要价值,其中QTc、JTc、QTd、QTcd是预测VT、VF及心性猝死的敏感指标。     

异甜菊醇对大鼠心肌缺血再灌注损伤的心电图影响

目的观察异甜菊醇对大鼠心肌缺血再灌注损伤的心电图影响,并探讨它的作用与线粒体ATP敏感性钾通道（mitoKATP）开放的关系。方法结扎大鼠冠状动脉30 min,再灌注90min,造成心肌缺血再灌注损伤模型。结扎前静脉注射异甜菊醇和/或选择mitoKATP关闭剂5-羟基癸酸（5-HD）进行预处理,观察各组大鼠在整个缺血再灌注期间心电图ST段和室性心律失常发生情况。结果预先给予异甜菊醇0.5、1.0和2.0mg/kg,能有效降低大鼠心肌缺血再灌注损伤引起的ST段变化和室性心律失常的发生率;但此作用可被预先给予的5-HD减弱。结论异甜菊醇能降低心肌缺血再灌注损伤程度和室性心律失常发生率,其机理可能与mitoKATP的开放有关。     

Association of cardiac ischemic score and coronary collateral circulation

Coronary collateral circulation maintains myocardial perfusion in coronary atherosclerotic disease. The indicators of cardiac ischemia, (Angina pectoris on exertion, during emotion, previous myocardial infarction and prior coronary intervention) are associated with presence of coronary collateral circulation. In this prospective observational cross sectional study, 128 patients with history of angina pectoris on exertion and or during emotion and or myocardial infarction and or previous coronary intervention were enrolled. The cardiac ischemic score (range 1-4) was calculated by adding 1 point for each of the above four clinical factors, which can be easily assessed. Presence of coronary collaterals in coronary angiogram was defined as Rentrop grade ≥1. Patients were divided into two groups. Group A patients having Rentrop grade 0 and Group B patients are with collateral circulation, having Rentrop grade 1-3. Patients having cardiac ischemic score (range 1-4) are compared in these groups. Maximum (83.3%) patients of Group B with coronary collateral circulation had cardiac ischemic score 2-4, but majority (86.4%) of Group A patients without collaterals showed the score only 1. Thus the cardiac ischemic score is strongly associated with the presence of coronary collaterals.     

氯苄律定静脉滴注抑制犬冠脉结扎引起的心律失常

目的：研究氯苄律定（86017）静脉滴注抑制犬冠脉结扎引起的心律失常,方法采用犬冠脉二次结扎诱发心律失常及心肌梗死,结果氯苄律定3mg/kg静脉滴注后,可使犬缺血必律失常及百分数明显减少,显著延长QT,减慢心率,减少犬二次结扎后的心肌梗死范围,血药浓度与药效显著有效血药浓度在1000ng/mL,结论氯苄律定具有抗心律失常作用并可减少心肌梗死面积。