主动脉内囊反搏和天麻注射液联合使用对山羊心肌缺血——再…

采用结扎２ｈ继而开放山羊冠状动脉分支方法，复制心肌缺血－－再灌注模型，观察主动脉内囊反搏和天麻注射液联合使用对心肌坏死区面积的影响。所得结果与二才单独使用的结果进行比较，发现主动脉内囊反搏和天麻注射液联合作用对限制心肌坏列区大小具有明显的协同作用。     

主动脉内囊反搏和生脉注射液对山羊心肌缺血的协同作用

山羊在麻醉和开胸的情况下结扎心室前壁的冠状动脉分支,观察主动脉内囊反搏和生脉注射液联合使用,对缺血心肌的影响(联合组)。研究结果与单独使用主动脉内囊反搏(反搏组)或生脉注射液(生脉组)的结果进行比较。用利多卡因的用量作为心律不齐出现的频度和严重程度。在抗心律不齐方面,主动脉内囊反搏和生脉注射液有协同作用。主动脉内囊反搏和生脉注射液,对限止心肌坏死区范围可能有协同作用的倾向。     

主动脉内囊反搏和生脉注射液对山羊心肌缺血的协同作用

主动脉内囊反搏能改善心肌缺血的变化,但有一定限度。本研究观察结合生脉注射液的处理,对心肌缺血的影响。在麻醉,开胸的情况下结扎山羊左冠状动脉的分肢造成心肌缺血。以结扎前、后的心电图和左心室压力和主动脉流量曲线,以及结扎后24小时的心肌坏死区大小来衡量上述治疗措     

体外反搏对心肌缺血犬RAS的影响及与血流动力学的关系

目的:探讨心肌缺血与体外反搏(ECP)时犬局部肾素-血管紧张素系统(RAS)和血流动力学的改变以及它们之间的关系。方法:采用冠状动脉结扎法复制犬急性心肌缺血模型,检测缺血及外加反搏时缺血心肌、主动脉、肾脏、肺等局部肾素活性、血管紧张素Ⅱ(AngⅡ)水平和血管紧张素转换酶(ACE)活性,用八导生理记录仪记录血流动力学,分析它们之间的关系。结果:缺血能激活缺血区心肌、主动脉处肾素、ACE和AngⅡ,除缺血区心肌肾素外,ECP抑制缺血区心肌与主动脉处三者。缺血还能激活对循环RAS影响较大的肾脏与肺RAS,反搏对其有一定抑制作用。缺血与反搏时的血流动力学改变和心血管局部AngⅡ水平有关。结论:体外反搏治疗心肌缺血时,局部RAS和血流动力学状态的改变呈相关关系,即体外反搏对血流动力学的改善作用和能抑制局部RAS有关,这可能是它对缺血心肌起保护作用的机制之一。     

体外反搏后心肌梗死犬心肌形态学的观察

目的：探讨体外反搏对心肌梗死犬超微结构的影响。方法：19只健康杂种犬随机分为对照组、梗死组和反搏组3组，采用透射电镜观察梗死区心肌组织的超微结构变化，并通过图像分析系统对线粒体进行形态定量分析。结果：形态学观察发现反搏组犬心肌肌小节、肌丝、线粒体和血管内皮细胞损伤比梗死组明显减轻。定量分析发现反搏组犬心肌线粒体数密度和比表面均明显高于梗死组，而线粒体体积和平均表面积均小于梗死组（P〈0．05）。结论：体外反搏可减轻心肌梗死犬的心肌超微结构损伤。     

体外反搏对缺血心肌穿壁血流影响的建模与仿真研究

在前期研究工作的基础上,为了深入研究体外反搏治疗心肌缺血的机理,用建模与仿真的方法研究体外反搏对缺血心肌跨壁血流的影响,以6条雄性犬的左心室压和主动脉压的实测数据作为输入对缺血心肌中的穿壁血流进行仿真。结果表明,用体外反搏的方法提高灌注压使缺血心肌穿壁血流进行仿真。结果表明,用体外反搏的方法提高灌注压使缺血心肌穿壁血流有明显增加。     

体外反搏对缺血心肌穿壁血流影响的建模与仿真研究

在前期研究工作的基础上 ,为了深入研究体外反搏治疗心肌缺血的机理 ,用建模与仿真的方法研究体外反搏对缺血心肌跨壁血流的影响 ,以 6条雄性犬的左心室压和主动脉压的实测数据作为输入对缺血心肌中的穿壁血流进行仿真。结果表明 ,用体外反搏的方法提高灌注压使缺血心肌穿壁血流有明显增加     

体外反搏对心肌缺血犬心肌超微结构的影响

目的探讨体外反搏对心肌缺血犬心肌超微结构的影响。方法19只健康杂种犬随机分为对照组、缺血组和反搏组,采用透射电镜观察缺血区心肌组织的超微结构变化,并通过图像分析系统对线粒体进行形态定量分析。结果形态学观察发现反搏组犬心肌肌小节、肌丝、线粒体和血管内皮细胞损伤比缺血组明显减轻。定量分析发现反搏组犬心肌线粒体数密度和比表面均明显高于缺血组,而线粒体体积和平均表面积均小于缺血组(P<0.05)。结论体外反搏可减轻心肌缺血犬的心肌超微结构损伤。     

灌注压变化对左冠脉血流影响的建模和仿真研究

目的　通过对左冠状动脉的建模与仿真 ,对体外反搏提高缺血心肌灌注血流的机理进行研究。方法　根据牛顿定律和连续性方程 ,用电路分析模型来表示冠状动脉的每一小部分。通过每个部分的模拟电路模型对整个左冠状动脉进行建模。以主动脉血压的实测数据作为输入数据 ,利用Pspice软件进行仿真。 结果　仿真结果表明在体外反搏的情况下 ,左冠状动脉分支在舒张期的灌注血流得到了明显提高。结论　使用体外反搏的方法改变灌注压可以提高左冠脉血流灌注     

体外反搏搏动性血流在动,静脉系统中的传递

体外反搏通过对下肢及臀部施加外压，将下肤及臀部的动、静脉血分别驱回主动脉和下腔静脉，产生上行性搏动血流。由于动、静脉的生理特性不同，体外反搏的搏动性血流在动、静系统中传导有所不同。本文观察体外反搏驱动的搏动性血流在狗的主动脉及下腔静脉中的传导。结果：反搏搏动性血流在主动脉中传导良好；而在下腔静脉中的传导衰减明显。结果表明：体外反搏驱动的搏动性血流在主动脉中的良好传导是反搏治疗的基础；而其在下腔静脉的衰减传导又是降低反搏治疗负效应的有利条件     

Ventricular energetics during mechanical ventilation and intraaortic balloon pumping--computer simulation.

Computer simulation of a cardiovascular system enabled us to predict the effects of simultaneous application of mechanical ventilation (MV) and intraaortic ballon pumping (IABP) on ventricular energetics. External work (EW), pressure-volume area (PVA), potential energy (PE) and cardiac mechanical efficiency (CME) were calculated. Nummerical simulation showed that changes of positive intrathoracic pressure have a considerable effect on left and right ventricular EW, PE, PVA and CME, whether IABP is used or not. The right ventricular energetics was much less influenced by systemic resistance (Ras) changes than the left ventricular one. Simultaneous application of IABP and MV showed a remarkable effect on left ventricular EW. The net result was reversed sensitivity to pulmonary resistance (Rap) and reduced sensitivity to Ras. PVA was generally reduced, while CME is increased by simultaneous presence of IABP and MV. The sensitivity of CME to Rap and Ras variation was diminished in this situation.     

冠状动脉狭窄时主动脉内气囊反搏对心内膜下动脉的影响

测量了左冠状动脉狭窄前后，主动脉内气囊反搏时，各项血流动力学参数，并用超声多普勒血流仪测量了室间隔动脉血流的变化。结果表明，当ＩＡＢＰ反搏时，加强了冠脉系统血流的脉动变化，在左冠状动脉主干狭窄时，对心内膜下小动脉的灌注产生不良影响。     

Mechanical circulatory assistance in the management of patients in coronary care unit

Mechanical circulatory assistance was attempted in 73 patients at our coronary care unit from January 1, 1983, to January 1, 1987. Of these, 62 were men and 11 were women. The intra-aortic balloon pump (IABP) was successfully inserted by percutaneous femoral puncture in all cases. Indications for an IABP included: acute infarction and haemodynamic deterioration (23 cases), refractory congestive heart failure (2 cases), hypotension, ST-T changes and chest pain complicating coronarography or coronary angioplasty procedures (16 cases), unstable angina pectoris resistent to medical therapy, treated by coronary angioplasty (16 cases) and preoperative haemodynamic coverage (16 cases). The overall major complication rate of IABP was 1.5%. Our experience supports aggressive management of cardiogenic shock, i.e. early angioplasty or cardiac surgery, which considerably influences the functional status and the long-term survival rate (7/9 cases) over medical therapy combined with IABP (2 of the 14 patients are alive). The IABP was also effective in managing other high-risk patients when it was combined with some form of definitive cardioprotective mechanical correction, i.e. aneurysmectomy, valve replacement, coronary recanalization procedure. When the counterpulsation was used prophylactically, no interventional myocardial infarctions or deaths occurred; the survival rate was 27/32 patients for a 22 month average follow-up. It is suggested that the clinical results and late survival were improved by use of IABP in selected patients undergoing coronary angioplasty or open-heart surgery.     

Current developments in oxygen concentrator technology

Computer simulation of a cardiovascular system enabled us to predict the effects of simultaneous application of mechanical ventilation (MV) and intraaortic ballon pumping (IABP) on ventricular energetics. External work (EW), pressure-volume area (PVA), potential energy (PE) and cardiac mechanical efficiency (CME) were calculated. Numerical simulation showed that changes of positive intrathoracic pressure have a considerable effect on left and right ventricular EW, PE, PVA and CME, whether IABP is used or not. The right ventricular energetics was much less influenced by systemic resistance (Ras) changes than the left ventricular one. Simultaneous application of IABP and MV showed a remarkable effect on left ventricular EW. The net result was reversed sensitivity to pulmonary resistance (R_ap) and reduced sensitivity to R_as. PVA was generally reduced, while CME is increased by simultaneous presence of IABP and MV. The sensitivity of CME to R_ap and R_as variation was diminished in this situation.     

主动脉内气囊反搏对人体外周血流影响的计算机仿真实验

主动脉内气囊反搏在心脏病临床上是重要的机械辅助疗法，应用广泛，气囊反搏对于人体外周血流的影响，与反搏的效果直接有关。作者应用计算机仿真的方法，对不同气囊反搏时，人体脑，肝，腹部及肾部血流的变化情况进行研究，研究侧重于多囊反搏。仿真结果表明：无论是单囊，还是双囊，三囊或四囊反搏均使脑，肝，腹部及肾部供血量增加；以脑部供血量增加幅度最大。就不同气囊而言，四囊反搏效果最佳，三囊稍逊，双囊略差，单囊反搏效     

PUCA pump and IABP comparison: analysis of hemodynamic and energetic effects using a digital computer model of the circulation

The pulsatile catheter pump (PUCA pump) is a left ventricular assist device that provides additional flow to the left ventricle. It is usually run in order to ensure a counterpulsation effect, as in the case of the intra-aortic balloon pump (IABP). Because of this similarity, a comparison between the PUCA pump and the IABP was conducted from both the hemodynamic and energetic points of view. Numerical models of the two devices were created and connected to the CARDIOSIM cardiovascular simulator. The PUCA and IABP models were then verified using in vivo experimental data and literature data, respectively. Numerical experiments were conducted for different values of left ventricular end systolic elastance (Els) and systemic arterial compliance (Csa). The energetic comparison was conducted taking into account the diastolic pressure time index and the endocardial viability ratio. Hemodynamic results expressed as cardiac output (CO) and mean coronary blood flow (CBF) show that both the IABP and the PUCA pump efficacy decrease with higher values of Els and Csa. The IABP especially shows higher sensitivity to these parameters, to the extent that in some cases CO actually drops and CBF does not increase. On the other hand, for lower values of Csa, IABP performance improves so much that the PUCA pump flow needs to be increased in order to ensure a hemodynamic effect comparable to that of the IABP. Energetic results show a trend similar to the hemodynamic ones. The study will be continued by investigating other energetic variables and the autonomic response of the cardiovascular system.     

骨髓间充质干细胞移植联合氯化锂治疗兔股骨头缺血坏死疗效

BACKGROUND: Lithium chloride can promote the proliferation and osteogenic capacity of bone marrow mesenchymal stem cells in the necrotic region after avascular necrosis of the femoral head, which has become an issue of concern. OBJECTIVE: To compare the advantages and disadvantages of bone marrow stem cell transplantation combined with lithium chloride in the treatment of rabbit femoral head necrosis. METHODS: Passage 2 bone marrow mesenchymal stem cells from 1-week-old New Zealand rabbits were cultured in 0, 5, 10, 20, 40 mmol/L lithium chloride. Forty-eight healthy adult New Zealand rabbits were selected to make femoral head necrosis models in the right femoral head using liquid nitrogen freezing method and then randomized into four groups: model group with no implantation; lithium chloride group given lithium chloride treatment at 3 days after modeling; cell transplantation group given gelatin sponge implantation and bone marrow mesenchymal stem cell suspension injection into the femoral head after modeling; combined group given bone marrow mesenchymal stem cell suspension injection and lithium chloride treatment. Intraperitoneal injection of lithium chloride (45.2 mg/kg) was given daily beginning at the postoperative 3rd day, and the treatment duration was 4 weeks. RESULTS AND CONCLUSION: Lithium chloride at 10 mmol/L had the maximum effect on the proliferation of rabbit bone marrow mesenchymal stem cells, and if the concentration of lithium chloride was > 10 mmol/L, the promotion role of lithium chloride began to decline. After combined treatment, the morphology of the femoral head was restored a little, with increased bone density and thickened trabecular bone; the level of β-catenin in the femoral head was significantly increased in the combined group compared with the cell transplantation group or the lithium chloride group. These findings show that bone marrow stem cell transplantation combined with lithium chloride treatment can promote the recovery from femoral head necrosis by increasing bone mass of the trabecular bone and bone density of the femoral head in the necrotic region.      

Computational prediction of the effects of the intra-aortic balloon pump on heart failure with valvular regurgitation using a 3D cardiac electromechanical model

Intra-aortic balloon pump (IABP) is normally contraindicated in significant aortic regurgitation (AR). It causes and aggravates pre-existing AR while performing well in the event of mitral regurgitation (MR). Indirect parameters, such as the mean systolic pressure, product of heart rate and peak systolic pressure, and pressure–volume are used to quantify the effect of IABP on ventricular workload. However, to date, no studies have directly quantified the reduction in workload with IABP. The goal of this study is to examine the effect of IABP therapy on ventricular mechanics under valvular insufficiency by using a computational model of the heart. For this purpose, the 3D electromechanical model of the failing ventricles used in previous studies was coupled with a lumped parameter model of valvular regurgitation and the IABP-treated vascular system. The IABP therapy was disturbed in terms of reducing the myocardial tension generation and contractile ATP consumption by valvular regurgitation, particularly in the AR condition. The IABP worsened the problem of ventricular expansion induced as a result of the regurgitated blood volume during the diastole under the AR condition. The IABP reduced the LV stroke work in the AR, MR, and no regurgitation conditions. Therefore, the IABP helped the ventricle to pump blood and reduced the ventricular workload. In conclusion, the IABP partially performed its role in the MR condition. However, it was disturbed by the AR and worsened the cardiovascular responses that followed the AR. Therefore, this study computationally proved the reason for the clinical contraindication of IABP in AR patients.     

Predicted hemodynamic benefits of counterpulsation therapy using a superficial surgical approach

A volume-displacement counterpulsation device (CPD) intended for chronic implantation via a superficial surgical approach is proposed. The CPD is a pneumatically driven sac that fills during native heart systole and empties during diastole through a single, valveless cannula anastomosed to the subclavian artery. Computer simulation was performed to predict and compare the physiological responses of the CPD to the intraaortic balloon pump (IABP) in a clinically relevant model of early stage heart failure. The effect of device stroke volume (0-50 ml) and control modes (timing, duration, morphology) on landmark hemodynamic parameters and the LV pressure-volume relationship were investigated. Simulation results predicted that the CPD would provide hemodynamic benefits comparable to an IABP as evidenced by up to 25% augmentation of peak diastolic aortic pressure, which increases diastolic coronary perfusion by up to 34%. The CPD may also provide up to 34% reduction in LV end-diastolic pressure and 12% reduction in peak systolic aortic pressure, lowering LV workload by up to 26% and increasing cardiac output by up to 10%. This study demonstrated that the superficial CPD technique may be used acutely to achieve similar improvements in hemodynamic function as the IABP in early stage heart failure patients.