心脏不停跳法行房,室间隔缺损修补术

心脏外科临床最常见的房,室间隔缺损修补术多在中低温体外循环以及心脏停搏中施实。心肌遭受缺血和再灌注损伤。我科于１９９６年５月－１９９７年３月施行浅低温体外循环心跳不停跳法,心内直视修补房,室间隔缺损。手术不阻断主动脉,不灌注心脏停跳液,临床效果良好。本组８例,房间隔缺损５例,室间隔缺损３例。年龄７－４３岁。直接缝合６例,用自体心包补片修补房间隔缺损２例。     

浅低温、不停跳心内直视手术的麻醉和体外循环管理

目的:探讨心内直视手术时不阻断主动脉、心脏不停跳的体外循环(CPB)和麻醉管理.方法:160例拟行心内直视手术的患者随机分为浅低温心脏不停跳组(观察组)和停跳组(对照组),各80例.所有病例采用综合血液保护措施.观察和分析各组患者一般情况、麻醉管理、体外循环时间、麻醉恢复和预后等指标.结果:两组患者平稳完成体外循环,最后均痊愈出院.观察组病人体外循环时间短,术后无严重并发症,苏醒及拔管时间明显缩短.两组自身输血42例(26.2%),未用库血共55例(34.3%).结论:浅低温、心脏不停跳下的心内直视手术安全可靠,能实现心肌的良好保护,加之综合血液保护措施,能显著减少手术相关并发症,患者恢复快,住院时间短,费用降低.     

围体外循环期肌钙蛋白Ⅰ的临床研究——判断心肌保护的一个新指标

目的探讨先天性心脏病(先心病)矫治术中心脏不停跳与心脏停跳两种术式对肌钙蛋白I(cTn-I)的影响,阐明cTn-I是判断不同术式心肌保护效果的一个新指标.方法36例先心病矫治术患者随机分为两组,冷晶体停跳组(组Ⅰ),心脏不停跳组(组Ⅱ).分别于各时段抽血,测定cTn-I、肌酸激酶(CK)、肌酸激酶同工酶(CK-MB)、乳酸脱氢酶(LDH).同时行电镜观察手术前后心肌超微结构变化.结果术后各时点组ⅠcTn-I明显高于组Ⅱ(P＜0.05);组Ⅰ CK-MB、CK、LDH明显高于组Ⅱ(P＜0.05).电镜观察组Ⅱ术后心肌超微结构无明显变化,而组Ⅰ受损程度分级与术前比较差异有显著性.结论先心病矫治术中心脏不停跳明显减轻了心肌缺血缺氧及再灌注损伤,减少了cTn-I的释放,较冷晶体停跳术有良好的心肌保护效果.肌钙蛋白I是判断心肌保护效果的一个灵敏的新指标.     

不停跳心内直视手术对心肌保护的研究

 目的 对比心脏不停跳与传统的停跳心内直视手术对先天性心脏病患者的影响,为心脏不停跳手术的临床开展提供理论依据.方法 同期收治房间隔缺损(ASD)、室间隔缺损(VSD)和肺动脉狭窄(PS)70例.随机分为体外循环(CPB)跳动下直视手术(实验组)和阻断升主动脉根部灌注冷晶体停搏液(对照组)行心内直视手术,每组35例.术前及术后1、2、6、12、24、48 h检测TNF-α、IL-6、 IL-8和IL-10、CK、cTnI含量.结果 实验组手术时间和体外循环时间较对照组明显缩短,术后多巴胺用量较少.患者血浆IL-6、IL-8、IL-10、TNF-α.含量在相同时点,实验组含量低于对照组(P＜0.05).术后 6 h、12 h,对照组CK、cTnI较实验组显著升高(P＜0.01).结论 浅低温CPB心脏跳动下心内直视手术对心肌的保护作用优于停跳组,是安全有效的.     

西宁地区不停跳心内直视手术治疗(附40例报告)

目的 :探讨西宁地区 (海拔 2 2 6 0m)心脏不停跳心内直视手术方法和意义。方法 :4 0例施行心脏不停跳心内直视手术 ,并行循环 ,阻断上、下腔静脉而不阻断升主动脉 ,不使用心脏停搏液 ,保持心脏处于空跳、慢跳状态下 ,浅低温 33℃± 1℃ ,完成心内直视手术。结果 :心内直视手术术毕即可停机 ,术后血流动力学平稳 ,血管活性药物用量少 ,无低心排及严重心律失常、无空气栓塞、无其它脏器损伤、术毕即可拔管 ,无一例手术死亡。结论 :浅体温、体外循环、心脏不停跳心内直视手术避免了心肌缺血再灌注损伤 ,有很好的心肌保护效果 ,为一种更接近生理状态下的心肌保护方法 ,减少体外循环并发症的发生 ,更适应在高原地区缺氧地区应用     

围体外循环期肌钙蛋白I的临床研究--判断心肌保护的一个新指标

目的:探讨先天性心脏病(先心病)矫治术中心脏不停跳与心脏停跳两种术式对肌钙蛋白I(cTn-I)的影响,阐明cTn-I是判断不同术式心肌保护效果的一个新指标.方法:36例先心病矫治术患者随机分为两组,冷晶体停跳组(组Ⅰ),心脏不停跳组(组Ⅱ).分别于各时段抽血,测定cTn-I、肌酸激酶(CK)、肌酸激酶同工酶(CK-MB)、乳酸脱氢酶(LDH).同时行电镜观察手术前后心肌超微结构变化.结果:术后各时点组ⅠcTn-I明显高于组Ⅱ(P＜0.05);组Ⅰ CK-MB、CK、LDH明显高于组Ⅱ(P＜0.05).电镜观察组Ⅱ术后心肌超微结构无明显变化,而组Ⅰ受损程度分级与术前比较差异有显著性.结论:先心病矫治术中心脏不停跳明显减轻了心肌缺血缺氧及再灌注损伤,减少了cTn-I的释放,较冷晶体停跳术有良好的心肌保护效果.肌钙蛋白I是判断心肌保护效果的一个灵敏的新指标.     

比较心脏不停跳与停跳行二尖瓣置换术心肌酶谱及线粒体的变化

目的比较心脏不停跳与停跳行二尖瓣置换术心肌保护的效果。方法将12例浅低温心脏不停跳二尖瓣置换术(BH)与12例冷晶体灌注心脏停跳下二尖瓣置换术(CCP)做比较,在麻醉后10 min,术后42、4、48、72 h这5个时点抽取周围静脉血测定血清CK、CK-MB、cTnI,MYO的变化。其中随机在BH组及CCP组各抽取10例,分别于体外循环(CPB)前和体外循环后取右心房心肌标本,在透射电子显微镜下观察线粒体形态并进行量化计分。结果 BH组术后各项指标虽较麻醉后增高,但增高幅度小于CCP组,在术后24 h均开始下降,72 h已基本接近正常。CCP组在术后24 h时各项指标除MYO外仍持续增高,72 h尚未恢复。体外循环后CCP组肌线粒体计分均高于BH组(P<0.01),BH组心肌超微结构优于CCP组。结论浅低温心脏不停跳较冷晶体灌注心脏停跳下行二尖瓣置换术具有更好的心肌保护效果。     

冷血含钾停跳液对心肌保护的作用

近年来,在心内直视手术中,临床应用最广泛的心肌保护,是冷钾停跳液(CK)结合心脏局部深低温的综合方法。但在术前心功能较差,以及复杂性心脏病的手术纠治中,保护效果仍嫌不足。许多学者利用新鲜氧合血作为心停跳液的载体,加强心肌保护,取得了显著的效果。本文就冷血含钾停跳液(CBK)加强心肌保护的作用及其机理综述如下。 一、应用CBK的理论基础 以血液作为心停跳液的赋形剂,除了具有CK的全部优点以外,还含有丰富的氧合血红蛋白和溶解氧,含胶体成份的缓冲系统,生理水平的代谢基质以及正常代谢的各种酶系等等。 心脏功能状态和心肌保护好坏与ATP水平密切相关,而能量供需平衡又与心肌氧的利用率不可分离。100ml CBK可携氧10～12ml,满足于心停跳期间心肌氧化代谢的需要,一般认为用CK,主动脉阻断     

体外循环中猫心肌细胞膜微粘度的变化

应用荧光偏振法观察中度代温体外循环冷晶体停搏液间断顺灌和冷血停搏液持续顺灌组,常温ＣＰＢ温血停搏液持续顺灌组猫心肌细胞膜微粘度η的变化。结果表明,主动脉阻断期间和再灌注早期,各组η均显著增大,心肌细胞膜流动性显著减小;其中Ｂ组改变最大,Ｄ组最小且再灌注后期恢复最快。     

浅低温体外循环心脏不停跳粘液瘤切除术32例临床观察

目的探讨心脏不停跳下心脏粘液瘤的手术方法，总结外科手术经验。方法回顾分析1998年10月-2007年10月原发性和复发性心脏粘液瘤病例32例，术中阻断上下腔静脉，不阻断升主动脉，不使用停跳液，鼻温维持在（33±1）℃，在心脏空跳下完成手术切除。结果心脏手术完毕即可停机，术后血液动力学平稳，无低心排发生，全组无死亡。结论心脏不停跳手术是一种接近生理状态的心肌保护手术方法，能最大限度地减少心肌缺血缺氧和再灌注损伤．是一种较理想的手术方法。     

不同心肌保护方法在双瓣膜置换术中对心肌的保护作用

目的探讨双瓣膜置换术（DVR）中更有效的心肌保护措施。方法选择2010年2月-2011年8月在我院行二尖瓣和主动脉瓣双瓣膜置换术的30例患者为研究对象,根据人院顺序将患者分为3组,每组10例。①顺行灌注组：经左、右冠状动脉开口顺行性灌注冷血心脏停搏液,完成双瓣膜置换术;②逆行灌注组：经冠状静脉窦间断逆行灌注冷血心脏停搏液,完成双瓣膜置换术;③顺逆联合灌注组：先按顺行灌注方法,再采用逆行灌注方法,完成双瓣膜置换术;观察3组术后早期临床疗效;观察心肌乳酸释放率、血清心肌肌钙蛋白I（cTnI）、磷酸肌酸激酶同工酶（CK-MB）的含量变化。结果30例患者无手术死亡,均痊愈出院。顺行灌注组和顺逆联合灌注组主动脉阻断60min时心肌乳酸浓度低于逆行灌注组。主动脉开放20min、术后第1d顺行灌注组和顺逆联合灌注组的血清CK-MB、cTnI浓度低于逆行灌注组。结论以上3种心肌保护方法均有效,但顺行灌注组和顺逆联合灌注组效果较好;顺逆联合灌注方法操作方便,不影响手术进程,是一种有效的选择。     

The calcified ascending aorta in aortocoronary bypass

Heavily calcified ascending aorta significantly increased morbidity and lethality during open-heart surgery. Cannulation and clamping (partial or total) of severely atherosclerotic ascending aorta can easily cause damage and rupture of aortic wall, with consequential distal (often fatal) embolization with atheromatous debris (brain, myocardium). From June 1998. until June 2000, 11 of 2,136 (0.5%) patients who underwent coronary artery bypass grafting were with the severe atheromatous ascending aorta. The site of cannulation was in the aortic arch in three patients (aorta was occluded with Foley catheter in one case, and single clamp technique was used in the other two cases). The femoral artery was the cannulation site in other five cases. Profound hypothermia, ventricular fibrillation, and circulatory arrest, with no cross-clamping or cardioplegia, were used in three patients. Two patients were operated on with extracorporeal circulation, one in normothermia, on the beating heart, the other in moderate hypothermia, on fibrillating heart. In three patients myocardial revascularization was performed on the beating heart, in normothermia, without extracorporeal circulation. Postoperative course was uneventful in all 11 patients. Neither atheroembolism in the peripheral organs, nor atheroembolism of the extremities occurred. The proposed surgical approaches have the potential to reduce the prevalence of stroke and systemic embolization associated with coronary artery bypass grafting in patients with heavily calcified ascending aorta. This result was achieved due to the applied modifications of standard cardiosurgical technique.     

Mechanism of thallium extraction in pump perfused canine hearts

Myocardial extraction of Tl has been postulated to depend on the rate of delivery (flow rate) and the metabolic state of tissue (ATPase activity). Experiments were performed to assess the role of these factors. In 22 arrested dog hearts the left anterior descending and circumflex coronary arteries were cannulated and pump perfused with oxygenated blood containing 204Tl. Isotope activity was determined in coronary sinus blood. The myocardial extraction ratio (E) of Tl varied inversely with flow, and the permeability-surface area product (PS) increased with increasing flow rates. These findings indicate that Tl uptake is flow dependent and can be analyzed with Renkin's capillary clearance theory. To assess the role of ATPase in Tl uptake, studies were also performed with blood containing ouabain. After introducing ouabain, coronary sinus blood Tl activity increased, approaching arterial activity, and E fell markedly. It was concluded that myocardial Tl uptake is mediated by ATPase.     

冠心病合并心脏瓣膜疾病的手术治疗

目的总结冠心病合并心脏瓣膜疾病的外科治疗方法。方法1998年4月-2004年12月，同期治疗57例冠心病合并心脏瓣膜疾病患者，平均年龄60岁（42～78岁）；心功能Ⅱ级9例，Ⅲ级37例，Ⅳ级11例；二尖瓣病变37例，主动脉瓣病变11例，联合瓣膜病变9例；均伴有单支或多支冠状动脉病变。手术在中低温体外循环下进行。心脏停跳后先做静脉桥的远端吻合，然后处理瓣膜。心脏复苏后在升主动脉开放前完成大隐静脉与升主动脉的吻合。乳内动脉的吻合在瓣膜置换或成形后心脏复苏前完成。本组行二尖瓣成形8例，行二尖瓣置换29例，行主动脉瓣置换11例，行双瓣置换9例（其中39例为机械瓣置换，10例为进口生物瓣置换）。冠脉搭桥1～5支，平均2．7支／例。结果术后早期死亡1例，死亡率为1．75％，其余患者住院期间无严重并发症。随访6个月～7年，无死亡，患者生活质量均明显提高，心功能Ⅰ级45例，Ⅱ级11例。结论同期施行冠状动脉旁路术和心脏瓣膜术安全有效。     

Effects of strenuous exercise on myocardial blood flow

Myocardial blood flow is the major determinant of oxygen delivery to the myocardium, since oxygen extraction by the myocardium is near maximum in the resting state. Regulation of flow during exercise depends on local metabolic factors and, to a small extent, on autonomic tone. Maximum flow of 5-6 times resting has been measured in reactive hyperemia experiments. In strenuous exercise, myocardial oxygen delivery appears to be adequate and flow reserve seems capable of handling the increased oxygen demand. No evidence of myocardial failure in normal hearts due to excess exercise has been presented. However, pulmonary hemorrhages found in horses after strenuous racing may be due to inadequate cardiac performance at maximal capacity. In humans, severe limitations to myocardial blood flow are imposed by coronary artery disease and by cardiac hypertrophy. In both cases regional myocardial ischemia may occur during the increased oxygen demands imposed by strenuous exercise. Individuals with coronary disease or cardiac hypertrophy are at risk for myocardial ischemia during exercise. Detection of myocardial blood flow abnormalities and ischemia during exercise has become an important goal in cardiac diagnosis. Prevention of serious or lethal consequence of strenuous exercise depends on a better understanding of the factors that regulate myocardial blood flow during ischemia.     

Effects of endurance training on coronary resistance in dogs

The effects of endurance training on coronary vascular resistance, myocardial blood flow, and oxygen consumption during tachycardia, and with adenosine-induced coronary dilation, were studied in a group of exercise-trained dogs. Seven mongrel dogs were conditioned by 8 wk of running on a motor-driven treadmill. Following conditioning, aortic pressure was unchanged in trained compared to a nontrained group, while cardiac output was somewhat lower in the trained group. Left ventricular myocardial blood flow determined by the microsphere technique was not different at rest or with tachycardia in trained vs control animals, and no significant differences in oxygen consumption were observed between trained and nontrained animals under any experimental conditions. Coronary resistance during pacing (NT: 1.00 +/- 0.09, T: 0.79 +/- 0.06 mmHg/ml X min-1 X 100 g-1) in the trained group was similar to the nontrained group, and both groups had the same resistance during adenosine infusion (NT: 0.49 +/- 0.20, T: 0.44 +/- 0.08). In addition, there were no differences in coronary A-V oxygen difference or coronary sinus saturation after training. The data indicate that little change occurs in the maximum flow capacity of the coronary bed following exercise training, and the trained heart responds to tachycardia with a reduced vascular resistance and increase coronary flow in a fashion similar to untrained animals.     

Quantitation of the regional blood flow in the interventricular septum using positron emission tomography and nitrogen-13 ammonia

The purpose of the present study was to evaluate the effect of spillover of activity from the right ventricle (RV) on quantitation of the regional myocardial blood flow in the septum. Thirty-one healthy volunteers, 31 patients with ischemic heart disease, 7 patients with severe congestive heart failure, and 6 heart transplant patients underwent positron emission tomography (PET) with nitrogen-13 ammonia. Quantitation of the regional myocardial blood flow in the septum was performed using both a conventional two-compartment model and a previously validated two-compartment model taking RV spillover into account. Unaccounted RV spillover resulted in significant underestimation of the regional myocardial blood flow in the septum. The amount of underestimation was primarily dependent on the magnitude of spillover and the dispersion between the right and the left ventricular input functions. In healthy volunteers, the flow error was small but significant: on average 6% (range 5%-29%, P<0.00001), compared with 27% (range 0%-88%, P<0.002) in the group of patients with severe congestive heart failure, who had the most considerable amount of RV spillover. In the group of patients with ischemic heart disease and the group of heart transplant patients the flow errors were 10% (range 0%-55%, P<0.00001) and 6% (range 1%-19%, P<0.01), respectively. It is concluded that flow quantitation in the septum is significantly affected by RV spillover, resulting in a considerable underestimation of the septal blood flow unless correction is performed.     

Simultaneous antegrade/retrograde cardioplegia protects myocardium distal to a coronary occlusion: a study in isolated pig hearts.

This study was designed to assess the effects of simultaneous antegrade/retrograde cardioplegia (SARC) on myocardial perfusion and energy metabolism in the region supported by the occluded left anterior descending artery (LAD) in isolated pig hearts. It was found that injection of Gd-DTPA into the aorta during antegrade cardioplegia (AC) did not result in signal increase in the LAD region on T(1)-weighted images. During SARC, however, Gd-DTPA was detected in the LAD region with the contrast agent injected into the aorta and the coronary sinus (CS), respectively. This suggests that SARC delivered blood cardioplegia to the jeopardized myocardium through both arterial and venous perfusion routes. Moreover, localized (31)P spectra showed that occlusion of the LAD during AC resulted in severe ischemic changes in the LAD myocardium and the abnormal metabolic changes were completely abolished by use of SARC. Finally, recovery of myocardial contractile function during reperfusion in the hearts subjected to SARC was significantly better compared to those arrested with AC alone. It was concluded that the myocardium distal to a coronary occlusion can be fully protected by use of SARC.