一体化综合性心肌保护对婴幼儿心肌超微结构的保护

目的：观察一体化综合性心肌保护方法对婴幼儿心肌超微结构的影响以评价其心肌保护效果。方法：30例复杂先天性心脏病患儿随机分成一体化综合性心肌保护组（综合组，含温血停搏液诱导停搏，冷血停搏液间歇灌注和终末温血灌注液复苏）、冷血停搏液间断灌注组（冷血组），及冷晶体停搏液间断灌注组（冷晶组），各10例。于心脏停跳即刻、缝合右心房切口前分别取小块右心房肌肉作光镜及电镜观察，并对线粒体、细胞核、肌纤维进行定量评估。结果：三组心肌均存在不同程度的损伤，冷晶组最重，综合组最轻。心肌超微结构评分在三组之间两两比较较有统计学意义（P〈0．01或P〈0．05）。结论：一体化综合性心肌保护作用优于冷血停搏液和冷晶体停搏液。     

冷血停搏液对5岁以下儿童先天性心脏病心肌保护效果的观察

目的本研究通过临床应用探索适用于5岁以下儿童心脏直视手术的心肌保护方法。 方法50例行择期法乐四联症根治术患儿随机分为2组对照组用冷晶体停搏液,实验组用冷血停搏液。阻断前,开放冠状动脉循环后1,3,10min分别由冠状静脉窦和动脉同时取血进行血气分析,并测定乳酸、丙二醛含量。术前、开放升主动脉后2,4,8,24,48h测定心肌酶谱。心脏停跳前,开放升主动脉后5min取右心室心肌观察超微结构改变,同时观察临床恢复情况。 结果实验组心电诱导停搏时间较长,量大,术后多巴酚丁胺及异丙肾上腺素平均最大剂量较高,使用时间较长,但心肌氧、乳酸摄取率恢复优于对照组(P＜0.05)。 结论冷血停搏液对紫绀型先天性心脏病患儿术中心肌保护效果较冷晶体停搏液无显著优越性。     

St.Thomas NO.2停跳液与含血心肌停跳液对未成熟兔心肌的保护作用

比较观察St.ThomasNO .2停跳液与含血心肌停跳液对未成熟兔心肌的保护作用 ,以期为未成熟心肌保护的临床应用找到一种更有效的方法。选用生后 14～ 2 1天新西兰兔 12只 ,在改良的Langendorff模型上 ,对St.ThomasNO .2停跳液及含血心肌停跳液分别进行低温缺血再灌注离体心脏实验。观察缺血前后心功能变化 (左心室最大压力变化速率、左心室搏出功、左心室搏出功指数及心输出量等指标 )、心肌含水率及心肌酶学的变化。结果发现 ,离体心脏缺血再灌后 ,含血心肌停跳液组左心室最大压力变化速率、左心室搏出功、左心室搏出功指数和心输出量等心功能指标恢复明显好于St.ThomasNO .2停跳液组 (P <0 .0 5 ) ;含血心肌停跳液组心肌肌酸激酶及乳酸脱氢酶漏出率与St.ThomasNO .2停跳液组相比明显降低 (P <0 .0 5 ) ;但两组心肌含水率无明显差异。结果提示 ,初步证实含血心肌停跳液对未成熟心肌的心肌保护效果比St.ThomasNO .2停跳液效果好     

婴幼儿心肌保护停搏液的温度处理

当前婴幼儿心脏外科手术中心肌保护技术尚未有比较统一的认识和方法。本文结合婴幼儿未成熟心肌在生理结构、代谢和功能上的特点,回顾和总结了低温与常温,晶体与血液灌注等技术各自的优缺点,并就温冷结合加终末温血灌注的一体化综合心肌保护技术作一综述。     

Effect of edaravone, a novel free radical scavenger, supplemented to cardioplegia on myocardial function after cardioplegic arrest: in vitro study of isolated rat heart

Cardioplegic arrest has been the main mechanism of myocardial protection during open-heart surgery; however, it causes myocardial injury during ischemia-reperfusion. Free radical scavengers are widely known to attenuate ischemia-reperfusion injury in various settings. We investigated the effects of edaravone, a novel free radical scavenger that was originally used for cerebral protection, on myocardial function during ischemia-reperfusion after cardioplegic arrest. Rat hearts were excised and perfused using Langendorff apparatus. The hearts were cardioplegically arrested for 90 min using St. Thomas’ Hospital cardioplegic solution (ST solution) at 4°C every 45 min and then reperfused for 20 min. The hearts were divided into 4 groups (n = 13 in each group). In Group ST, the hearts were arrested using the ST solution alone. In Groups L, M, and H, the hearts were arrested using the ST solution supplemented with a low-dose (1 μM), moderate dose (10 μM), and high dose (100 μM) of edaravone, respectively. Left ventricular function (+dp/dt _max) and the levels of the cardiac enzymes released were measured before and after cardioplegic arrest. At the end of the study, the water content and the tissue oxidative stress (8-hydroxy-2′-deoxyguanosine) of the heart were measured. During reperfusion, the edaravone-treated groups showed a greater functional recovery with regard to the +dp/dt _max (P < 0.05). The lactate level was the lowest (P < 0.01) in Group M. The water content of the hearts in the edaravone-treated groups was significantly lower (P < 0.05) than that in Group ST. Oxidative stress was significantly lower (P < 0.01) in the edaravone-treated hearts than in Group ST, and it was the lowest in Group M. The addition of edaravone to the cardioplegic solution ameliorates the impairment in myocardial function by reducing the oxidative stress after cardioplegic arrest. In this study, the maximum improvement in the myocardial function was achieved by addition of a moderate dose (10 μM) of edaravone.     

自体冷血停跳液保护未成熟心肌的价值

目的研究自体冷血停跳液在婴幼儿心内直视手术中保护未成熟心肌的价值。方法婴幼儿（体重≤8k）非发绀型先天性心脏病30例,随机分为自体冷血（A组）、冷血（B组）和晶体（C组）停跳液组,每组10例。分别于术前,术毕,术后24、48h经桡动脉抽血检测心肌肌钙蛋白I（cTnI）及磷酸肌酸激酶同功酶（CK—MB）,术中记录复跳时间、室颤发生率和自动复跳率,术后监测心脏指数（CI）。结果术后cTnI和CK—MB明显升高,以后逐渐下降,同组手术前、后比较,cTnI术毕明显升高（P〈0．01）,CK—MB术后24h达到高峰（P〈0．05、P〈0．01）。A组与B组、C组比较,复跳时间、cTnI和CK—MB差异有统计学意义（P〈0．05、P〈0．01）;CIA组优于B和C组;室颤发生率和自动复跳率各组差异无统计学意义。B组与C组比较,复跳时间和cTnI差异有统计学意义（P〈0．05）;CIB组优于C组。结论自体冷血停跳液优于冷血和晶体停跳液,对婴幼儿心内直视手术保护未成熟心肌有重要价值。     

Myocardial protective effect of deep hypothermic cardiac arrest without aortic cross clamp in neonatal hearts: Comparison with cardioplegic arrest in a rabbit model

Summary Using an isolated perfusion model of neonatal rabbit hearts aged 3 to 6 days, cardioplegic arrest (CPA) using crystalloid cold cardioplegia with aortic cross clamp (AXC: 60min,n = 15) and continuous deep hypothermic perfusion (DHP) at 15°C without AXC (n = 15) were compared. The hearts were divided into two subgroups: intact hearts (n = 18) and with preceding 40min warm ischemia (stressed hearts,n = 22). In the intact hearts, there were no significant differences between the CPA and DHP groups in left ventricular function, myocardial water content, and myocardial mitochondrial score after reperfusion. In the stressed hearts, recovery of cardiac output and left ventricular work was significantly higher in the DHP group than in the CPA group. The postreperfusion myocardial mitochondrial score was significantly better in the DHP group than in the CPA group. These results suggest that non-AXC DHP may be advantageous in the setting of stressed hearts with preceding ischemic injury where conventional CPA cannot provide adequate myocardial protection.