瓣膜置换术中HTK液和高钾停搏液对心肌保护作用的比较研究

【目的】比较康斯特保护液（HTK液）和含血高钾停搏液在风湿性心脏病患者瓣膜置换术中的心肌保护效果。【方法】51例风湿性心脏病联合瓣膜病的患者随机分为对照组（应用4：1冷含血停搏液,n=21）和试验组（应用HTK液,n=30）。分别于术前、术后24h、72h、7d时检测外周静脉血中B型脑钠肽（BNP）和心肌肌钙蛋白I（cTnI）水平,并比较两组患者主动脉阻断时间、主动脉开放到心脏复跳时间、辅助循环时间、心脏自动复跳率、心律失常、起搏器应用、多巴胺平均最大剂量、呼吸机支持时间等临床指标。【结果】试验组术后BNP与cTnI升高水平均低于对照组（P〈0．05）;主动脉阻断时间、主动脉开放到心脏复跳时间、辅助循环时间,多巴胺平均最大剂量、呼吸机支持时间均低于对照组（P〈0．05）,心脏自动复跳率高于对照组（P〈0．05）,术后出现心律失常、低心排和使用临时心脏起搏器的患者数在试验组中明显减少。【结论】HTK心脏停搏液对风湿性心脏病患者瓣膜置换术中心肌的保护作用优于1：4含血停搏液。     

Effect of antegrade graft cardioplegia combined with passive graft perfusion in on-pump coronary artery bypass grafting

Patients undergoing on-pump coronary artery bypass graft (CABG) with proximal graft anastomosis were randomly divided into groups that received antegrade cardioplegic infusion only via the aortic root (group A) or antegrade cardioplegic infusion via the aortic root and additional cardioplegia via vein or free arterial grafts after completion of each distal anastomosis (group B). The group B patients also received bypass graft perfusion with warm arterial blood just after removal of the cross-clamp until the proximal graft anastomosis was completed. The need for defibrillation and inotropic support during separation from cardiopulmonary bypass (CPB), and total CPB time were significantly lower in group B than in group A. Group B also had significantly lower peak cardiac troponin I levels 12 h after operation compared with group A and this was more pronounced in subgroups with severe right coronary artery stenosis and poor left ventricular ejection fraction than in the whole population. It is concluded that antegrade graft cardioplegia and graft perfusion with warm blood during proximal graft anastomosis may improve myocardial protection.     

心肌保护方法

体外循环心脏手术的心肌保护是心脏外科的一个重要课题。冷晶体停搏液、含血停搏液的心肌保护作用已被广泛研究证实,但该两种心肌保护方法均存在不同程度的心肌缺血性损伤和再灌注损伤。跳动中心内直视手术不阻断心肌血供,避免了心肌缺血损伤及再灌注损伤,临床使用已观察到较冷晶体停跳、含血停跳心脏手术更好的心肌保护作用。     

紫外线照射充氧自体血心脏停搏液对犬体外循环手术时心肌线粒体的影响

目的 研究紫外线照射充氧自体血（UBIO）心脏停搏液对犬体外循环（CPB）心内直视手术时心肌线粒体的影响。 方法 选取20只雄性杂交犬,按随机数字表法将其分为对照组和UBIO心脏停搏液组（UBIO组）,每组10只。建立犬CPB心内直视手术模型,CPB中对照组使用普通含血心脏停搏液,实验组采用UBIO心脏停搏液。在阻断升主动脉前和开放升主动脉后,分别从冠状静脉窦取血,检测血清心肌肌钙蛋白I(cTnI)和肌酸激酶同工酶(CK-MB)水平。在打开和关闭右心房时,分别取右心房组织标本,采用化学比色法检测组织匀浆线粒体超氧化物歧化酶（SOD）活性、谷胱甘肽过氧化物酶（GSH-Px）活性及丙二醛（MDA）含量,同时测定心肌线粒体膨胀度。 结果 阻断升主动脉前,2组犬cTnI、CK-MB含量之间比较,差异无统计学意义（P>0.05）。在开放升主动脉后,对照组cTnI、CK-MB含量高于UBIO组,差异有统计学意义（P<0.05)。打开右心房时,2组犬心肌组织匀浆SOD活性、GSH-Px活性和MDA含量之间比较,差异无统计学意义（P>0.05）。关闭右心房时,2组犬心肌组织匀浆SOD活性、GSH-Px活性低于打开右心房时的SOD活性、GSH-Px活性（P<0.05）。2组犬关闭右心房时的MDA含量均高于组内打开右心房时的MDA含量（P<0.05)。关闭右心房时,UBIO组心肌组织匀浆SOD活性［（34.1±5.1）KNU/g］、GSH-Px活性［（44.2±7.4）kat/g］高于对照组SOD活性［（20.5±4.3）KNU/g］、GSH-Px活性［（32.7±6.3）kat/g］,MDA含量［（6.9±1.2）mol/L］低于对照组［（9.5±1.9）mol/L］（P<0.05)。UBIO组线粒体膨胀度改变较小。 结论 CPB心内直视手术时存在心肌线粒体清除氧自由基能力下降及线粒体本身脂质过氧化反应,UBIO心脏停搏液可以保持线粒体清除氧自由基的能力,并减轻线粒体本身的受攻击程度,较好地维持线粒体结构与功能,减轻心肌损伤。     

Leucocyte-depleted blood cardioplegia

The effect of the depletion of leucocytes from cardioplegic and initial myocardial reperfusion blood on the inflammatory response and myocardial protection in patients with unstable angina undergoing cardiopulmonary bypass (CPB) was studied. Patients were allocated randomly to a leucocyte-depleted (LD) group or a control group. The LD group received continuous retrograde LD isothermic blood cardioplegia and the control group received isothermic blood cardioplegia. Blood samples were collected at seven time-points before, during and after the procedure. Total leucocyte counts of cardioplegia blood in the LD group were significantly lower than in the control group, but systemic leucocyte and neutrophil counts after CPB did not differ between the groups. The levels of adhesion molecules, cytokines, elastase and malondialdehyde were significantly increased after CPB in both groups and reached peak values 2-6 h after surgery; no other significant differences were found. LD cardioplegia and myocardial reperfusion did not attenuate the endothelial and neutrophil-mediated components of the CPB-induced inflammatory response, which may lead to myocardial reperfusion injury.     

含乌司他丁自体冷血心脏停搏液对婴儿心脏直视术后心功能的影响

目的探讨含乌司他丁自体冷血心脏停搏液对婴儿体外循环心脏直视手术心功能的影响。方法年龄≤10个月行体外循环室间隔缺损修补术的患儿60例,应用随机数字表法随机分成自体冷血停搏液组30例（A组）、含乌司他丁冷血停搏液组30例（B组）。分别于主动脉开放后1、6h测量左心做功指数（LCWI）、心脏指数（CI）及每搏指数（sI）,监测术中心脏复跳时间及复跳率,正性肌力药物依赖情况。结果两组自主复跳率差异无统计学意义（P〉0．05）;B组心脏自动复跳时间[（34．2±4．7）s]及正性肌力药物依赖[40．0％（12／30）]均明显低于A组（52．1±6．5）s和66．7％（20／30）,差异有统计学意义（t=2．001、t=1．895,P均〈0．05）;B组术后不同时点CI及SI、LCWI高于A组,差异有统计学意义（P均〈0．05）。结论含乌司他丁自体冷血停搏液利于婴儿体外循环直视手术后心脏功能恢复,对未成熟心肌有良好的保护作用。     

Comparison of three strategies for myocardial protection during coronary artery bypass graft surgery based on markers of cardiac damage

OBJECTIVES: To evaluate myocardial damage during coronary artery bypass grafting using three different intermittent cardioplegia and then measuring cTnI and CKMBm release. DESIGN AND METHODS: Forty-two patients belonging to the hypothermic crystalloid (n = 16), hypothermic (n = 13), and normothermic blood (n = 13) groups were collected when removing the aortic cross-clamp (t = 0) and after 4, 12, 24 and 48 h. For each patient, cumulative cTnI and CKMBm release was calculated as the five measurement mean. There were no significant preoperative and operative differences in the three groups. RESULTS: In the normothermic group, cTnI mean values at 4, 12, and 24 h were significantly lower than those in both hypothermic groups; moreover, CKMBm mean values were higher at 4, 12, and 24 h in the hypothermic crystalloid group and at 4 and 12 h in the hypothermic blood group than in the normothermic group. In the normothermic group, the area under the curve of the release of both markers was significantly lower than in the hypothermic groups. No significant difference was reported in the release of both markers in hypothermic groups. CONCLUSIONS: A strategy of normothermic cardioplegia seems to preserve myocardium better than hypothermic cardioplegia.     

Comparison of simultaneous antegrade/vein graft cardioplegia with antegrade cardioplegia for myocardial protection

Antegrade cardioplegic delivery via the aorta ensures distribution of cardioplegic solution through open arteries, but distribution may not be adequate beyond a stenotic coronary artery. This potential problem can be overcome by direct delivery of cardioplegia via a vein graft. The purpose of this study was to compare simultaneous antegrade/vein graft cardioplegia with antegrade cardioplegia during coronary artery bypass surgery. Twenty patients were divided into 2 groups. In group 1, intermittent antegrade cardioplegia was provided (n=10). In group 2, intermittent antegrade cardioplegia was supplemented by antegrade perfusion of vein grafts after distal anastomoses were completed (n=10). Data on enzyme release and hemodynamics were obtained preoperatively, before the induction of anesthesia, just before cross-clamping, immediately after aortic unclamping, and at 1, 6, 12, 24, and 48 h after unclamping. Enzyme release (creatinine phosphokinase-isoenzyme MB, cardiac troponin I, myoglobin) was similar in both groups (P > .05). Furthermore, no significant difference was noted in the incidence of postoperative low cardiac output syndrome, perioperative myocardial infarction, or ventricular arrhythmia (P > .05). In conclusion, both techniques permitted rapid postoperative recovery of myocardial function. Supplementation of antegrade perfusion of vein grafts with antegrade cold blood cardioplegia offered no advantage to study patients. However, hemostasis of a distal anastomosis may be controlled by this technique.     

心脏手术麻醉过程中温血灌注与冷晶体灌注对心肌保护作用的对比研究

目的　研究心脏手术麻醉过程中温血灌注液和冷晶体灌注液对心肌的保护作用。方法　选择 2 0例体外循环心内直视手术的老年患者 ,随机分为 2组 :I组 ,温血组 ,给予 37℃温血全钾和温血半钾灌注液 ;II组 ,冷晶组 ,给予4℃常规的冷晶体灌注。两组分别于体外循环机转动前、停机后 12h、术后 2 4h抽血测定血清谷草转氨酶 (GOT)、乳酸脱氢酶 (LDH)、肌酸磷酸激酶 (creatinekinase ,CK)和肌酸磷酸激酶同工酶 (CK MB) ,检测心脏复跳情况。结果　两组体外循环机转机时间和阻断时间无统计学差异 (P >0 0 5 ) ;温血组复跳情况优于冷晶组 ;温血组GOT、LDH、CK和CK MB的升高低于冷晶组 ,有显著性差异 (P <0 0 5 )。结论　温血全钾和半钾灌注方法明显优于冷晶体灌注液对心肌的保护作用 ;温血灌注方法是一种有效、实用的心肌保护法     

冠状动脉搭桥手术的体外循环方法

目的:总结冠状动脉搭桥手术的体外循环方法.方法:对1998～2003年的132例冠状动脉搭桥手术的体外循环情况进行总结,分析其临床资料、术中搭桥支数、体外循环时间、阻断时间、转流温度、停跳液使用情况、术后呼吸机时间、多巴胺支持率和IABP使用的情况.结果:132例患者平均搭桥3.2支,体外循环时间63～213min,平均132min,升主动脉阻断时间39～148min,平均52min.4:1(血:晶体液)含血停跳液温-冷-温方法灌注结合桥灌,较好地保护了心肌.应用抑肽酶和乌司他丁,更好地做好血液保护和心肌保护.主动脉内球囊反搏在救治低心排患者时起到重要而有效的作用.结论:含血停跳液温-冷-温方法灌注结合桥灌,合理的体外循环方法,充分的血液保护对提高冠状动脉搭桥手术成功率起重要作用.     

诱导室颤间断阻断主动脉后的心肌酶与超微结构变化

目的：常规心肌保护采用主动脉阻断灌注晶体、冷血、温血停跳液,本文研究诱导室颤主动脉间断阻断技术在冠状动脉搭桥术中的心肌保护作用。方法：选取18例诱导室颤主动脉间断阻断冠脉搭桥术患者为观察组（室颤组）,同期10例心脏冷停跳换瓣病人为对照组。测定体外循环前、体外循环后30min、60min、90min、术后第1天及第2天血清心肌酶谱和肌钙蛋白水平,并取左室心肌标本作扫描电镜观察。结果：体外循环前室颤组心肌酶谱和肌钙蛋白水平高于对照组,术后两组均升高而且与主动脉阻断时间和体外循环时间呈正比。术后第1天心肌酶谱和肌钙蛋白水平达最高峰,对照组明显高于室颤组。术后第2天室颤组心肌酶谱和肌钙蛋白水平下降接近体外前水平,但对照组仍不能降至体外循环的前水平,而且为室颤组的两倍。心肌电镜扫描发现室颤组体外循环90min后心肌细胞轻度受损,而对照组心肌缺血60min后就有中度心肌细胞破坏。结论：诱导室颤间断阻断主动脉技术对于冠状动脉搭桥术是一种安全有效的心肌保护方法。     

老年人工生物瓣膜置换过程中紫外线照射充氧血首次灌注对心肌的保护

背景:动物实验表明将紫外线照射充氧血添加于心停搏液中有一定的心肌保护作用,故推测其对体外循环心内直视手术患者的心肌也有保护作用.目的:课题提出使用紫外线照射充氧血行首次冠状动脉顺行灌注,观察其在老年患者人工生物心脏瓣膜置换体外循环过程中是否对心肌有保护作用.设计、时间及地点:生化水平的随机对照试验,于2006-10/2008-04在贵州省人民医院心脏外科完成.对象:选择贵州省人民医院心脏外科收治需择期行人工生物瓣膜置换的风湿性心脏瓣膜病老年患者46例,按随机数字表法分为2组,每组23例.方法:紫外线照射充氧血组于麻醉后通过锁骨下静脉按10 m/kg放血行紫外线照射充氧(同时经另一静脉途径输入等量生理盐水,术前经过计算,体外循环过程中血红蛋白低于70g/L者,用库血代替自体血行紫外线照射充氧),升主动脉阻断后,将紫外线照射充氧血作为心停搏液组成成分进行首次冠状动脉顺行灌注,之后每30 min常规以4:1冷血/晶体灌注.对照组首次冠状动脉顺行灌注使用不含紫外线照射充氧血的4:1冷血/晶体外,其他处理同治疗组.主要观察指标:于升主动脉阻断前,升主动脉开放后5,10 min从冠状静脉窦取血2 mL,测定超氧化物歧化酶活性及丙二醛浓度.在升主动脉阻断前,停体外循环后4,24,48 h时从中心静脉取血2 mL,测定肌酸激酶同工酶活性及肌钙蛋白I质量浓度.结果:开放升主动脉后,紫外线照射充氧血组冠状静脉窦血清丙二醛浓度低于对照组(P＜0.05),超氧化物歧化酶活性显著高于对照组(P<0.05).紫外线照射充氧血组停体外循环后4-48 的血清肌酸激酶同工酶活性及肌钙蛋白I质量浓度显著低于对照组(P< 0.05).结论:体外循环过程中首次冠状动脉顺行灌注紫外线照射充氧血能提高心肌细胞超氧化物歧化酶活性,减少丙二醛产生,减轻心肌缺血再灌注损伤.降低心肌损伤标志物水平,对老年人工生物心脏瓣膜置换患者具有较好的心肌保护作用.     

Cardioplegia and ventricular late potentials in cardiac surgical patients

Background and objective  

Ventricular late potentials (LP) recording with signal-averaged electrocar- diogram allow identifying patients at risk of sudden death and ventricular tachycardia. Cardiac surgery with cardiopulmonary bypass (CPB) could predispose to the development of myocardial ischemia related to imperfect cardioplegia. To the best of our knowledge, no study investigated the protection of cardioplegia and CPB regarding the occurrence of LP in patients without previous myocardial infarction and undergoing cardiac surgery.     

Mitochondrial ischemia-reperfusion injury of the transplanted rat heart: improved protection by preservation versus cardioplegic solutions

Cold ischemia time and preservation of organs are limited by I/R injury leading to primary nonfunction of the graft. In a rat heart transplant model, we compared cardioplegic St Thomas (ST) to histidine-tryptophan-ketoglutarate (HTK) and University of Wisconsin preservation solutions in terms of contractile function, and mitochondrial respiratory and enzymatic defects after prolonged cold ischemia and reperfusion. Contractile function was scored after transplantation and 24 h of reperfusion. Mitochondrial function was investigated by high-resolution respirometry of permeabilized myocardial fibers. Graft performance in terms of contractile function declined with the duration of cold storage. Recovery was significantly improved after 10 h of cold storage in HTK compared with ST (cardiac scores, 3.3+/-0.5 and 1.8+/-0.8, respectively). Tissue lactate dehydrogenase was better preserved in HTK than ST. Increase of tissue water content (edema) was less pronounced in HTK than ST (3.33+/-0.14 and 3.73+/-0.21 mg/mg dry weight, respectively). Similar cardiac scores (2.6+/-0.9 and 2.9+/-1.2, respectively) and mitochondrial respiratory parameters were obtained after preservation in HTK and University of Wisconsin. Decline in contractile function of individual grafts correlated well with loss of mitochondrial respiratory capacity, whereas citrate synthase activity remained largely preserved, indicating specific damage of respiratory complexes. Our data provide evidence for the superiority of preservation solutions versus a cardioplegic solution for prolonged cold storage of the heart. The correlation of graft performance and mitochondrial function indicates the potential of high-resolution respirometry for quantitative assessment of myocardial injury upon cold I/R, providing a basis for diagnostic approaches and evaluation of improved preservation solutions for heart transplantation.     

A simplified technique for antegrade selective cerebral perfusion

Various methods of cerebral protection have been used during aortic arch surgery. We reviewed our experience with a modified technique for selective cerebral perfusion (SCP) administration during surgery on the thoracic aorta from October 1999. Conventionally, this technique requires an additional roller pump on the cardiopulmonary bypass (CPB) console. In order to simplify the extracorporeal circuit (ECC), the paediatric double-roller pump used for the administration of cardioplegia was utilized by adding a 'Y-connection' on the blood line of the cardioplegia circuit, upstream of the cardioplegia reservoir, to provide SCP blood flow. SCP administration with a Y-connection is both easy and fast to set up on the ECC circuit and does not create additional difficulties to the surgeon. It simplifies SCP delivery by allowing the perfusionist to use a standard ECC system set-up.     

Short periods of regional ischaemia and reperfusion provoke release of troponin I from the human hearts.

Whether cardiac troponin I (cTnI) is better at detecting minor myocardial damage than other biochemical markers, is still controversial. In this report we monitored the response of the human heart to short periods of regional ischaemia and reperfusion (3 min each) by measuring cTnI release in the coronary sinus and the radial artery of patients undergoing coronary revascularisation surgery on beating heart without cardiopulmonary bypass. Our data show for the first time that the human heart releases significant amounts of cTnI in response to minor cardiac insults. However because of dilution, this release cannot be easily detected outside the coronary circulation. Therefore, an improved sensitivity of the assays used to measure cTnI may provide an ideal tool for assessing minor myocardial damage.     

HTK液及Celsior液对长时间低温保存心肌保护作用的对比研究

目的比较不同种类心脏保存液对长时间低温保存心肌的保护作用。方法将36只雄性Wistar大鼠随机分成4组,即KH组、常规停搏液组（RCP组）、HTK组及Celsior组,每组9只,制作大鼠离体工作心脏模型。RCP组、HTK组及Celsior组分别采用常规心脏停搏液、HTK液及Celsior液低温保存心脏8h后,检测冠状动脉流出液中乳酸脱氢酶和肌酸激酶同功酶含量及心肌组织形态学改变;KH组即刻恢复做功。结果低温保存心脏8h后,Celsior组冠状动脉流出液中乳酸脱氢酶和肌酸激酶同功酶含量低于HTK组,HTK组明显低于RCP组,差异均有统计学意义（P〈0.05）。结论细胞外液型心脏保存液Celsior液心脏保存效果优于HTK液及常规心脏停搏液。     

Sex-based differences in serum cardiac troponin I,a specific marker for myocardial injury,after cardiac surgery

BACKGROUND: Prevalence and causes of sex-based differences in morbidity and mortality secondary to cardiovascular disease remain controversial. Cardiac troponin I (cTnI) is a sensitive and specific marker for myocardial injury. Serial cTnI measurements have been used to identify perioperative myocardial cell injury. OBJECTIVE: To determine whether sex influences the extent of myocardial injury during cardiac surgery, we measured perioperative cTnI in male and female patients. DESIGN: A total of 17 male and 17 female patients were prospectively studied in an age- and case-matched manner. Arterial cTnI were obtained preinduction, 30 mins after the application of the aortic cross-clamp, at arrival to the intensive care unit, and on postoperative day 1. SETTING: Tertiary cardiac surgery center at a major teaching hospital. RESULTS: There was no difference between men and women in body mass index (kg/m2), duration of cardiopulmonary bypass, and aortic cross-clamp times. Preoperative cTnI measurements were similar in men (0.24 +/- 0.15 ng/mL) and women (0.25 +/- 0.13 ng/mL, mean +/- sem). The maximum serum cTnI occurred on postoperative day 1 in all patients, and it was 3-fold higher in men (18.5 +/- 5.7 ng/mL) compared with women (6.4 +/- 1.0 ng/mL). CONCLUSIONS: Men had markedly higher serum cTnI compared with women, although they were case matched with respect to age and cardiac risk factors. Our results may suggest there may be sex-related differences in the myocardial response to ischemia and reperfusion injury or intrinsic differences between the male and female myocardium.     

Use of the pacing pulmonary arterial catheter to detect endocardial electrical activity during hypothermic cardioplegic arrest

The pacing Swan-Ganz catheter was evaluated for its ability to monitor atrial and ventricular electrical activity during cardioplegic arrest on cardiopulmonary bypass. This endocardial electrical activity was compared with the activity found on the standard electrocardiogram (ECG). The atrial electrodes detected activity that was noted also by visual inspection. The ventricular electrodes detected recurring electrical activity in 7 of 18 patients. Three of these 7 patients did not have simultaneous standard ECG activity, indicating that, in the usual monitoring circumstances, this ventricular electrical activity would not have been treated with repeat cardioplegia. If the pacing Swan-Ganz catheter is used for clinical care, it can be used also to monitor myocardial electrical activity during cardioplegic arrest.     

Cardiomyocytic apoptosis following global cardiac ischemia and reperfusion can be attenuated by peroxisome proliferator-activated receptor alpha but not gamma activators

In this study, experiments were designed to determine if peroxisome proliferator-activated receptor (PPAR) alpha agonists could decrease myocardial ischemia/reperfusion injury after cardioplegia-induced cardiac arrest under cardiopulmonary bypass, attenuate the appearance of cardiomyocytic apoptosis, and decrease the damage of reactive oxygen species. Cardiomyocytic apoptosis occurs after cardiopulmonary bypass surgery. Reactive oxygen species and peroxynitrite generated during ischemia/reperfusion initiate the formation of single-strand DNA breaks. Peroxisome proliferator-activated receptors (PPARs) activators had an important role in alleviating myocardial apoptosis. Four groups of New Zealand white rabbits (10 in each group, each 2.5-3.5 kg) underwent cardiopulmonary bypass. Thirty minutes before surgery, one group received WY14643 (a PPAR-alpha agonist, 1 mg kg(-1)) and another received 15D-PGJ2 (a PPAR-gamma agonist; 0.3 mg kg(-1)). The ascending aorta was cross-clamped for 60 min, whereas intermittent cold crystalloid cardioplegic solution was infused into the aortic root every 20 min. The myocardium of the reperfused hearts and control hearts were harvested and studied in vitro for evidence of apoptosis using terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling method and Western blot analyses of cytochrome c and apoptosis-inducing factor. The reactive oxidative insults were checked using enzyme-linked immunosorbent assay to detect plasma cytokine levels. The occurrence of cardiomyocytic apoptosis and elevation of plasma cytokines were significantly lower in the group receiving PPAR-alpha agonists than in the other groups. Western blot analysis of apoptosis-inducing factor and cytochrome c revealed similar patterns. PPAR-alpha activation could diminish postischemic cardiomyocytic apoptosis and reactive oxygen species injuries after global cardiac arrest under cardiopulmonary bypass, possibly via prevention of both caspase-dependent and caspase-independent apoptotic pathways.