双龙方对犬心脏血流动力学及心肌耗氧量的影响

目的：研究双龙方对麻醉开胸犬心脏血流动力学及心肌耗氧量的影响，探索其对心脏功能的药理作用及作用机制。方法：观察麻醉犬冠状动脉血流量、心肌耗氧量和心率等指标的变化。结果：双龙方具有增加犬冠状动脉血流量、降低心率等作用。结论：双龙方对犬心脏血流动力学及心肌耗氧量有调整和改善作用。     

Effects of myocardial revascularization on regional thallium-201 uptake and systolic function in regions with reverse redistribution on tomographic thallium-201 imaging at rest in patients with chronic coronary artery disease

Objectives  There is growing evidence that myocardial segments with reverse redistribution are viable in patients with chronic coronary artery disease. The aim of this study was to assess the effects of myocardial revascularization on systolic function and thallium-201 uptake in such segments. Methods  Rest-redistribution thallium-201 tomography before and after myocardial revascularization was performed in 47 patients with chronic coronary artery disease. Regional function was evaluated by two-dimensional echocardiography before and after revascularization according to a 3-point scale (1=normal, 2=hypokinetic, 3=a/dyskinetic). Improvement of dysfunctional segments was defined when systolic function score decreased ≥1 after revascularization. Reverse redistribution was defined as ≥8% decrease in relative thallium-201 uptake between rest and redistribution images. Results  Reverse redistribution was found in 27 (57%) of 47 patients, corresponding to 60 (11%) of 564 myocardial segments. Of such segments, 24 (40%) had normal systolic function, 19 (32%) were hypokinetic, and 17 (28%) were a/dyskinetic. Thirty-six segments underwent myocardial revascularization, and reverse redistribution was no longer present in 86% of them subsequent to the procedure. Of 26 dyssynergic segments with reverse redistribution subjected to revascularization, 18 (69%) improved at follow-up. Conclusions  The findings of the present study indicate that reverse redistribution is a reversible phenomenon and is often associated with improvement of systolic function following revascularization in patients with chronic coronary artery disease.     

Effects of Rb1 from the Panax notoginseng saponins on arrhythmia and Ca2+ movement in rat heart cells

We determined the antiarrhythmic effect of Rb₁ (from Panax notoginseng) on different arrhythmia models and its effect on cytoplasmic Ca²⁺ concentrations ([Ca²⁺]i) in rat heart cells with fura-2 fluorescence. At doses of 30 and 50 mg/Kg, Rb₁ produced an antirrhythmic effect on BaCl₂-induced ventricular tachyarrhythmia in rats, atrial fibrillation induced by CaCl₂-ACh, and ventricular fibrillation induced by chloroform in mice. The rest [Ca²⁺]i was 108 ± 10.7 nM in the freshly isolated rat heart cells. Sixty mM KCl caused an increase in [Ca²⁺]i to 379.4 ± 77 nM. Rb₁ from 0.1 to 0.8 mM significantly reduced this increase in a concentration-dependent manner. mM Rb₁ (0.4 mM) also completely inhibited the increase in [Ca²⁺]i induced by 1 μM isoprenaline. The radioligand binding study in rat heart cells showed that Rb₁ did not change the B_max and K_d values of [³H]-dihydroalprenolol binding. These data suggest Rb₁ can inhibit Ca²⁺ entry through voltage-dependent and receptor-linked Ca²⁺ channels, and that this is related to its antiarrhythmic effect. Drug Dev. Res. 39:179–183. © 1997 Wiley-Liss, Inc.     

血管紧张素-(1-7)对血管加压素诱导心脏成纤维细胞增殖和胶原合成的影响

目的: 研究血管紧张素-(1-7)[Ang-(1-7)]对血管加压素(AVP)诱导心脏成纤维细胞(CFs)增殖和胶原合成的影响.方法:分离培养SD仔鼠CFs,四氮唑盐(MTT)比色法检测细胞增殖,流式细胞分析仪测定细胞周期,逆转录-聚合酶链式反应(RT-PCR)测定CFsⅠ,Ⅲ型胶原mRNA的表达.结果: ① 0.1 μmol/L AVP作用24 h,CFs的MTT吸光度值(0.24±0.01)较无血清对照组(0.14±0.01)明显增加(P<0.01);0.001～1 μmol/L Ang-(1-7)和0.1 μmol/L AVP共同干预后吸光度值逐渐降低,分别为0.22±0.01,0.21±0.01,0.18±0.01和0.16±0.01,均显著低于AVP组(P<0.01).② AVP组CFs的S期百分率(14.00±0.94)和增殖指数(23.44±1.75)较对照组(5.40±0.67和10.82±2.40)明显增高(P<0.01);0.1 μmol/L Ang-(1-7)干预后S期百分率(8.52±0.70)和增殖指数(16.24±2.04)较AVP组降低(P<0.01).③ AVP刺激后CFs的Ⅰ,Ⅲ型胶原mRNA表达水平分别较对照组明显增高(P<0.01);给予0.001～1 μmol/L Ang-(1-7)和0.1 μmol/L AVP共同干预后,胶原表达水平浓度依赖性的下降,均显著低于AVP组(P<0.05).结论: Ang-(1-7)具有抑制CFs增殖和胶原合成的作用.     

Gated single-photon emission tomography imaging protocol to evaluate myocardial stunning after exercise

This study was designed to apply ECG-gating to stress myocardial perfusion single-photon emission tomography (SPET) for the evaluation of myocardial stunning after exercise. Technetium-99m sestamibi was selected as the perfusion agent and a rest/exercise 1-day protocol was employed. Fourteen patients without coronary stenosis and 33 patients with coronary stenosis were enrolled in the study. We carried out three data acquisitions with ECG-gating: a 15-min data acquisition starting 30 min after the rest injection (AC1), a 5-min acquisition starting 5 min after the stress injection (AC2) and a 15-min acquisition starting 20 min after the stress injection (AC3). Calculation of left ventricular ejection fraction (LVEF) values was performed by means of automatic determination of the endocardial surface for all gating intervals in the cardiac cycle. Measured global EF values in 14 patients without coronary stenosis were 52.3%±7.6% (AC1), 60.6%±8.9% (AC2) and 55.6%± 5.6% (AC3), and those in 11 patients with severe ischaemia were 53.6%±8.0% (AC1), 45.6%±12.1% (AC2) and 49.7%±10.7%. The magnitude of the depression of post-stress LVEF relative to the rest LVEF correlated with the severity of ischaemia (r=0.594, P=0.002), and segments manifesting post-stress functional depression were associated with ischaemic segments showing reversible perfusion defects. Stress myocardial perfusion SPET with ECG-gating is a feasible method for the evaluation of myocardial stunning as well as exercise-induced ischaemia. Received 13 June and in revised form 19 August 1999     

卡托普利对家兔慢性冬眠心肌的保护作用

目的评价血管紧张素转换酶抑制剂(ACEI)-卡托普利对缺血心肌的药理作用。方法建立家兔慢性冬眠心肌(CHM)模型,观察卡托普利对CHM组织间质纤维化、凋亡及心功能的影响。结果卡托普利可抑制CHM组织问质纤维化、减少凋亡细胞、改善心功能。结论卡托普利对缺血心肌具有保护作用。     

心脏电机械活性标测系统检测心肌梗死后存活心肌

目的探讨心脏电机械活性标测系统(NOGATM)检测心肌梗死后存活心肌的可行性及应用价值。方法建立苏中幼猪急性心肌梗死模型,1 个月后分别行99mTc MIBI 18 F FDG双核素(DISA)心肌显像及NOGATM标测,DISA图像及标测三维重建图像采取9分段法进行对比分析。结果正常心肌(14 0±4 5) mV、存活心肌(9 8±3 5) mV、坏死心肌(4 3±2 7) mV之间单极电压值有显著性差异(P<0 05或<0 01)。以12 5 mV作为判断正常心肌界值,敏感性和特异性均为85%;以6 9 mV作为判断坏死心肌界值,敏感性为82%,特异性为75%。结论NOGATM可以用来检测存活心肌,单极电压低于6 9 mV提示心肌坏死。     

小剂量多巴酚丁胺- 硝酸甘油超声心动图试验检测存活心肌的研究

目的 评价小剂量多巴酚丁胺－硝酸甘油超声心动图（ＤＮＥ０检测存活心肌的临床价值。方法 心肌梗塞后伴节优性室壁运动异常患者３６例,接受梗塞相关血管经皮３腔内冠状动脉成形术（ＰＴＣＡ）前进行ＤＮＥ试验。ＰＴＣＡ后随访９个月,将ＤＮＥ识别为存活心肌的室壁节段与实际运动改善节段做对比判定ＤＮＥ检测存活心肌的准确性。结果 ＤＮＥ检测存活心肌的敏感性、特异性及准确性分别为８０％、８１％及８２％。结论 ＤＮＥ为