Abstract： Objective To explore clinical outcomes of nitroglycerin perfusion via the aortic root before heart re-beating for patients undergoing heart valve replacement. Methods A total of 254 patients with valvular heart diseases underwent heart valve replacement in Beijing Anzhen Hospital from January 2008 to December 2011. According to whether or not they received nitroglycerin perfusion via the aortic root before heart re-beating during cardiopulmonary bypass （CPB）， all the 254 patients were randomly divided into two groups， the nitroglycerin group and the control group. There were 134 patients in the nitroglycerin group including 57 males and 77 females with their average age of 58.47±12.34 years. They received aortic root perfusion of 5 mg nitroglycerin diluted into 20 ml after full de-airing of the heart， and repeated aspiration was performed 8 to 10 times before heart re-beating during CPB. Aortic cross-clamp was released after the heart showed signs of automatic re-beating， and the aortic root was squeezed in high frequency by hand to make sure that the aorta was squeezed to close each time. In the control group， there were 120 patients including 64 males and 56 females with their average age of 61.85±11.97 years. Patients in the control group received routine procedures of CPB except nitroglycerin perfusion before heart re-beating. Automatic heart re-beating rate， CPB supporting time after heart re-beating， postoperative usage of inotropic drugs， mechanical ventilation time， perioperative morbidity and length of hospital stay were compared between the 2 groups， and patients were followed up and further evaluated. Results There was no in-hospital death. CPB supporting time after heart re-beating（12.32±9.76 min vs. 23.43±10.33 min， t=-1.233， P=0.000）， dopamine usage［3.45±2.33 μg/ （kg?min） vs. 5.67±3.12 μg/ （kg?min） ， t=-0.943 ， P=0.034］ and epinephrine usage ［0.026±0.013 μg/ （kg?min） vs. 0.056±0.021 μg/ （kg?min） ， t=-0.822 ， P=0.027］ of the nitroglycerin group were significantly shorter or lower than those of the control group. Automatic heart re-beating rate of the nitroglycerin group was significantly higher than that of the control group ［97.01% vs. 66.67 % ， χ 2 =-2.115 ， P=0.000］. A total of 121 patients in the nitroglycerin group were followed up for 2-36 months， and 13 patients were lost during follow-up. There was no death during follow-up. Conclusion For patients undergoing heart valve replacement， some myocardial protection strategies including nitroglycerin perfusion via the aortic root before heart re-beating， use of norepinephrine， and aortic root squeezing in high frequency by hand can significantly increase the automatic heart re-beating rate， shorten the CPB supporting time after heart re-beating， and improve postoperative clinical outcomes.
Abstract： Objective To observe myocardial protective effect of sevoflurane used in the whole process of cardiopulmonary bypass（CPB）. Methods A total of 150 patients older than 18 years who underwent cardiac surgery under CPB in Fu wai Hospital from January 2010 to November 2011 were enrolled in this double-blind and randomized controlled study. All the patients were randomly divided into three groups：Sevoflurane pretreatment group （Group A，n=50），whole-process Sevoflurane group （Group B，n=50），and whole-process intravenous anesthesia group （Group C，n=50）. Radial artery pressure and other hemodynamic parameters were continuously measured for all the patients. At following time points: CPB beginning （T1），aortic declamping （T2），3 hours after aortic declamping （T3），and 24 hours after aortic declamping （T4），serum concentrations of cardiac troponin I （cTnI） and other parameters were measured by enzyme-linked immunosorbent assay （ELISA）. Results There were 31 males and 19 females at age of 60.43±3.24 years in group A，28 males and 22 females at age of 59.88±4.12 years in group B，31 males and 19 females at age of 58.76±3.87 years. There was no statistical difference in mean arterial pressure （MAP），central venous pressure （CVP），pulmonary artery wedge pressure （PAWP） and heart rate （HR） at respective time points among the 3 groups （P＞0.05）. At T1 and T2，there was no statistical difference in cardiac index （CI） among the 3 groups （P＞0.05）. At T3，there was no statistical difference in CI between Group A and Group C（F=3.382，P=0.845），but CI of Group B was significantly higher than that of Group A and C（F=3.382，3.382； P=0.033，0.020）. At T4，CI of Group B was significantly higher than that of Group A and C （F=13.324，13.324； P=0.005，P=0.000），and CI of Group A was significantly higher than that of Group C （F=13.324，P=0.024）. At T1 and T2，there was no statistical difference in serum concentrations of creatinine kinase MB （CK-MB），cTnI，interleukin-6 （IL-6） and tumor necrosis factor alpha （TNF-α） among the 3 groups （P＞0.05）. At T3 and T4，serum concentrations of CK-MB，TNF-α，IL-6 and cTnI of Group C were significantly higher than those of Group A，and serum concentrations of CK-MB，TNF-α，IL-6 and cTnI of Group A were significantly higher than those of Group B （F=531.616，5.410，3.5813，3.160，1.126，4.702，7.819，5.424，all P=0.000）. Conclusion Sevoflurane used in the whole process of CPB has definite myocardial protective effect which is ber than that of Sevoflurane pretreatment.
Abstract： Ischemia postconditioning is a new concept based on ischemic preconditioning. It has become a hot topic in protection of ischemic-reperfusion injury because of its effective protection, relative ease of application, and postconditioning. However, its precise mechanisms and most effective application methods are still unclear. This review covers recent progress in the understanding, developments (in remote postconditioning and pharmacological postconditioning), applications to the protection of heart, lung, liver, kidney, and brain, mechanisms and appropriate protocol of ischemic post-conditioning.
Abstract: Objective To evaluate myocardial protection effect of different myocardial protective strategies for patients undergoing double valve replacement （DVR） . Methods From Jun. 2005 to Dec. 2005, 32 patients with predominant aortic valve stenosis undergoing DVR in Xinqiao Hospital were included in this study. These patients were randomly divided into four groups with 8 patients in each group： （1） antegrade perfusion group：Cold-blood cardioplegia was delivered antegradely through aortic root, and mitral valve replacement （MVR）was performed. Then cold-blood cardioplegia was delivered antegradely through left and right coronary ostia, and aortic valve replacement （AVR） was performed； （2）retrograde perfusion group：Cold-blood cardioplegia was delivered retrogradely and intermittently through coronary sinus, and DVR was performed； （3）antegrade＋retrograde perfusion group：The route of cold-blood cardioplegic infusion was antegrade during MVR procedure first and then retrograde during AVR procedure；and （4）beating heart group：Oxygenated blood from cardiopulmonary bypass machine was delivered retrogradely and continuously through coronary sinus, and DVR was performed with beating heart. Early clinical outcomes were observed. Serum cardiac troponin I （cTnI） was measured by enzyme-linked immunosorbent assay（ELISA）. Serum creatine kinase-MB （CK-MB） and myocardial lactic acid release rate were measured by Hitachi7150 Automatic Chemistry Analyzer. Myocardial mitochondria malondialdehyde （MDA） level was measured through thiobarbituric acid reagent species analysis. Results All the 32 patients survived their surgery and were discharged successfully. Myocardial lactic acid release rate at 80 min after aortic cross-clamping, serum cTnI and CK-MB on the first postoperative day, myocardial mitochondria MDA levels of beating heart group were 13.59%±6.27%,（1.17±0.25） ng/ml, （56.43±16.50） U/L and（2.18±1.23） nmol/（ng.prot）respectively, all significantly lower than those of retrograde perfusion group ［（33.49%±8.29%, （1.82±0.58 ）ng/ml, （78.31±21.27） U/L （5.07±2.35） nmol/（ng.prot），P＜0.05］ and antegrade＋retrograde perfusion group［20.87%±7.22%, （1.49±0.23） ng/ml,（66.67±19.13） U/L,（4.34±1.73） nmol/（ng.prot），P＜0.05］, but not statistically different from those of antegrade perfusion group ［18.83%±5.97%, （1.41±0.32） ng/ml, （63.21±37.52） U/L, （3.46±1.62） nmol/ （ng.prot），P＞0.05］. Conclusion All the four myocardial protective strategies are effective myocardial protection methods for DVR patients. Continuous retrograde perfusion with beating heart and intermittent antegrade perfusion can provide better myocardial protection, and therefore are preferred for DVR patients. The combination of antegrade and retrograde perfusion is easy to administer and does not negatively influence surgical procedures. Retrograde perfusion is also effective as it takes only a short time.
Objective To summarize the experiences of donor heart procurement of heart transplantation so as to improve the efficiency of donor heart protection. [WTHZ]Methods [WTBZ]From April 2002 to October 2006, sixtyone patients with endstage heart disease had undergone orthotopic heart transplantation. Donors were all male brain deaths, aged from 21 to 53, and 5 of them were older than 40. There were 6 cases in which the weight difference between donor and recipient＞20%, and the rest ≤±20%. Fortyfive cases had the same ABO blood type, and 16 had matching ABO blood type. Four donor hearts were procured under the condition of stable hemodynamics and enough oxygen after brain death(typeⅠ), fortyfour donor hearts were procured under the condition of brain death with acute hemorrhage and hypovolemia (typeⅡ), and 13 donor hearts were procured under the condition of brain death with cardiac arrest (typeⅢ). Twenty cases underwent standard transplantation procedure, one underwent total heart transplantation procedure and 40 underwent bicaval transplantation procedure. The donor heart cold ischemic period ranged from 52 to 347 min（92±31 min）, and 13 cases were more than 240 min. Results Two cases died of low cardiac output syndrome on 7th and 9th day after operation respectively, and their donor heart cold ischemic period were 327 and 293 min respectively. The rest of patients all recovered and discharged. One died of acute rejection on 18th month after operation because of rejecting immunosuppressive agents, and 1 died in traffic accident on 23rd month after transplantation. The rest 57 cases survived 6-59 months(mean 35 months), and had good life quality with NYHA cardiac function classification in 0-I grade. Conclusions Heart transplantation with donor aged over 40 may also have satisfactory results. Patients with endstage dilated cardiomyopathy can procure donor heartsfrom donors with heavy weight. Using different techniques to procure donor hearts may furthest reduce myocardial injury. Donor hearts which have been protected by myocardium protecting liquid for a long time should be used with caution.
Objective To observe the protective effects of diazoxide-preconditioning on myocardial ischemiareperfusion injury of rats and discuss its possible mechanisms. Methods Fourteen healthy SD rats were randomly divided into two groups（7 each group）,In diazoxide-preconditioning group diazoxide was injected with the dosage of 12.5mg/kg through the vein,and in control group the media with the same amount was only given before ischemia. The left anterior descending branch was ligated for 2 hours. The heart was quickly excised after 2 hours reperfusion to be used for measurement of the quantity of malondialdehyde（MDA）, the activity of superoxide dismutase （SOD）, the size of myocardial infarct area, and the cell apoptosis and ultrastructure in ischemic area. Results Compared with the control group, the quantity of MDA,the percentage of the weight of myocardial infarct area/ischemic area, and the rate of cell apoptosis in the diazoxide-preconditioning group were greatly reduced （P〈0.05, 0. 01）. The damage of cell uhrastructure was obviously alleviated,Conclusion Diazoxide-preconditioning provides evident cardioprotective effect on the myocardial ischemia-reperfusion injury of rats.
Objective To investigate the protective effects of ischemic postconditioning (IPo) on ischemiareperfusion (I/R) myocardium and the relationship with mitochondrial adenosine triphosphate (ATP) sensitive K+ channels (mitoKATP) and provide evidences to the development of druginduced postconditioning. Methods Langendorff models were established in 40 Wistar rats which were divided into 5 groups by random number table with 8 rats in each group. Normal control group(NC group): the rat hearts were continuously reperfused by KrebsHenseleit bicarbonate buffer (K-HB) for 100 min without any other treatment; I/R group: the rat hearts underwent a 40-min global ischemia followed by a 60-min reperfusion; IPo group: after a 40-min global ischemia, the process of 10-second reperfusion followed by a 10-second ischemia was repeated 6 times, then there was a continuous 58min reperfusion; 5-hydroxydecanoic acid(5-HD) group: after a 40min global ischemia, hearts with 5HD(100 μmol/L) K-HB were reperfused for 15min and then perfused without 5HD for 45min；IPo+5-HD group: after a 40-min global ischemia, the process that the isolated hearts with 5-HD(100 μmol/L) KHB were reperfused for 10second followed by a 10second ischemia was repeated 6 times, then the hearts with 5-HD(100 μmol/L) KHB were continuously [CM(159mm]perfused for 13-min followed by reperfusion without 5-HD(100 μmol/L) K-HB for 45-min. The cardiac function,coronary flow(CF), cardiac troponin I(cTnI) content in coronary effluent, the area of acute myocardial infarction (AMI) and myocardial ultrastructure were observed. Results Left ventricular developed pressure(74.3±3.3 mm Hg vs. 57.1±3.3 mm Hg,t=1300, P=0.000),+dp/dtmax(1 706.6±135.6 mm Hg/s vs. 1 313.3±96.2 mm Hg/s,t=6.28,P=0.000),－dp/dtmax(1 132.8±112.1 mm Hg/s vs. 575.7±67.7 mm Hg/s,t=13.48, P=0.000) and CF(6.49±0.30 ml/min vs. 3.70±0.24 ml/min,t=28.6,P=0.000) in IPo group were higher than those in I/R group. Left ventricular enddiastolic pressure(10.9±1.7mm Hg vs. 26.2±1.5 mm Hg,t=－19.21, P=0000)and cTnI content in coronary effluent (0.62±0.01 ng/ml vs. 0.71±0.01 ng/ml, t=-12.00,P=0.000) were lower than those in I/R group; the area of AMI decreased 20.8％ compared with that in I/R group (Plt;0.05). The myocardial protective effect in IPo+5HD group was similar with that in IPo group, but lower than that in IPo group. The electron microscope showed that IPo and IPo+5HD could reduce myocardial fiber damage and mitochondrial damage caused by I/R. Conclusion IPo can protect I/R myocardium, which is achieved mainly by activating mitoK-ATP channels.
Objective To investigate the effect of polyethylene glycolbovine hemoglobin (PEG-bHb), which was used as an oxygen carrier in cardioplegic solution, on the protection of isolated rat hearts. Methods The hearts of 32 male SD rats were harvested and transferred to Langendorff circuit. They were divided into 4 groups according to cardiocplegia: St.Thomas group (group A), 1∶2 PEG-bHb group (group B), 1∶4 PEG-bHb group (group C) and 1∶8 PEG-bHb group (group D). After 20min balance period, hearts were perfused with cold (4℃) cardioplegic solutions, and preserved at 30℃ for 60min, then reperfused. Levels of cardiac troponin I (cTn I) and adenosine triphosphate(ATP) contant in coronary effuent were detected, and ultrastructures of myocardium were observed. Results After reperfusion, cTn I contant of group A were higher (F=52.955,Plt;0.05) and ATP contant were lower (F=68.757,Plt;0.05) than those in group B, group C and group D. Myocardial water contant were lower in group B and group C(F=3.048,Plt;0.05). Conclusion PEG-bHb in cardioplegic solutions can provide better myocardial protection during ischemia.
Objective To investigate the immature myocardial protection effects with renal ischemic preconditioning. Methods 18 neonatal rabbits were randomly divided into three groups. Ischemic/reperfusion(I/R) group underwent 45 min ischemia followed with 45 min reperfusion after Langendorff model performed. Cardiac ischemic preconditioning(CIP) group underwent 45 min ischemia followed with 45 min reperfusion after 5 min ischemia and then 5 min reperfusion for two times. Renal ischemic preconditioning(RIP) group underwent 45 min ischemia followed with 45 min reperfusion after renal artery obstruction for 5 min and 5 min reperfusion for three times.The left ventricular function recovery,myocardial water content(MWC), lactate dehydrogenase (LDH) and creatine kinase(CK) leakage, malondialdehyde(MDA) content,adenosine triphosphate(ATP) content, superoxide dismutase(SOD) activity, myocardial cell Ca2+ ［Ca2+］c content,mitochondrial Ca 2+ content ［Ca2+］m,synthesizing ATP activity of mitochondria ［ATP］m and Ca2+ATPase activity of mitochondria ［Ca2+ATPase］m were tested. Results The recovery of postischemic heart function in RIP group and CIP group were higher than that I/R group(Plt;0.01). There were no significant difference of HR, AF in three groups （Pgt;0.05）. There were significant difference of CF，CO，LVSP and LVEDP in RIP group and CIP group than those I/R group（Plt;0.01）. There were significant difference of MWC, CK, LDH, ATP content, MDA, SOD activity, ［Ca2+］c content, ［Ca2+ATPase］m， ［Ca2+］m and ［ATP］m in RIP group than those I/R group（Plt;0.01). There were no significant difference between RIP group and CIP group upon every index (Pgt;0.05). Conclusion RIP has the same cardioprotection to immature myocardium as ischemic preconditioning.
Hemoglobin-based oxygen carriers (HBOCs) is a kind of blood substitutes. It is a separated, ultra-purified, modified human or bovine hemoglobin in a balanced saline solution. After modification, it has longer half-time, less renal toxicity, and better delivery of O2 even at low temperature and pH. Its shelf life is long and it dose not require cross-matching. In the field of cardiac surgery, the use of HBOCs can reduce the amount of transfusion postoperatively, and can be used in cardiopulmonary bypass priming and myocardial protection.