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.
ObjectiveTo retrospectively compare and analyze the effect of myocardial protection between histidinetryptophane-ketoglutarate (HTK) and 4:1 blood cardioplegia in patients with complex coronary artery disease and left ventricular dysfunction. MethodsFrom January 2003 to July 2013, 2132 patients underwent isolated coronary artery bypass grafting (CABG) in our institution. Among them, 227 patients with complex coronary artery disease (left main or triple vessel disease) and left ventricular dysfunction (ejection fraction ≤ 50%) were included in this study. According to the category of cardioplegia utilized in the operations, the patients were divided into two groups: a HTK group (85 males and 4 females, n=89) and a blood cardioplegia group (113 males and 25 females, n=138). The average age was 62.78±9.30 years in the HTK group and 62.74±9.07 years in the blood cardioplegia group. The effect of myocardial protection between two groups was compared. ResultsAccording to the pre-operational data of these two groups, there was no significant difference identified in terms of basic characteristics and risk factors, even though more female patients were found in the blood cardiophegia group and more patients with renal dysfunction were found in the HTK group. In addition, the patients in the HTK group had more distal anastomosis, longer cardiopulmonary time and cross clamping time than those in the blood cardiophegia group. Based on the results measured by those primary assessment criteria,there was no significant difference being found between these two groups. However, on those secondary assessment criteria the pulmonary pressure and inotropic support after reperfusion were significantly higher in the HTK group than its counterpart. ConclusionFor patients with complex coronary artery disease and left ventricular dysfunction, HTK solution and blood cardioplegia provide similar effective myocardial protection. HTK doesn't significantly increase postoperative adverse cardiovascular events under the circumstance of longer ischemic time.
Erythropoietin （EPO） is known as a classical hematopoietic growth factor, which has been used to treat anemia caused by different reasons. In recent years, EPO＇s non-hematopoietic biological effects have gradually become a focus. Among these effects, EPO＇s tissue protection is most attractive and EPO has been proved to protect many different tissues and organs. Myocardial protection has always been the important and key topic in the field of cardiovascular diseases. Reports about EPO＇s myocardial protective effects have been published in the recent two years, which direct the research about myocardial protection with new ideas. In this article, the discoveries and unsolved problems associated with EPO＇s myocardial protection were reviewed.
Cardiac injury is a major complication of cardiac surgery. Surgical manipulation, systemic inflammatory response and cardiac ischemia/reperfusion injury (IRI)are main reasons of cardiac injury. Gentle and swift surgical manipulation can reduce mechanical myocardial injury, shorten myocardial ischemic time, and reduce myocardial IRI. Satisfactory myocardial protection plays a key role to improve postoperative recovery. In recent years, more and more myocardial protection strategies are employed to reduce myocardial IRI and improve myocardial protection, including modifications of temperature, composition and instillation approach of cardioplegia in order to increase myocardial oxygen supply, decrease myocardial oxygen consumption, inhibit inflammatory response and eliminate oxygen free radicals. Endogenous myocardial protection is also achieved by supplement of certain medications in cardioplegia.
Objective To investigate the value of systemic-normothermic/cardiac-hypothermic cardiopulmonary bypass（CPB）on operation of congenital heart disease. Methods Thirty patients of congenital heart disease were randomly divided into two groups, the normothermia group（n=15）and hypothermia group（n=15）. The changes of CPB time, aortic cross-clamp time,operation time and postoperative drainage and the value of blood cell were observed. Results The duration of CPB （37. 5 ±11. 6rain vs. 51. 6± 12. 0 min, P〈0. 05） and operation time （2.2± 0.6h vs. 2. 7±0. 5h, P〈0. 01） in normothermia group were shorter than those of hypothermia group statistically, the differences of postoperative drainage and the value of blood cells between two groups were not statistically significant. Conclusion The use of systemic-normothermic/cardiac-hypothermic CPB on operation of congenital heart disease shows that the time of operation is shorter remarkly , and it could be clinically used safely.
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.
Objective To systematically review the influence of tight heart rate (HR) control on the efficacy of perioperative β-blockade, and discuss the effective measures of perioperative myocardial protection. Methods We searched the PubMed, OVID, EMbase, the Cochrane Library and Chinese Biomedical Database (CBM) for randomized controlled trials on evaluating perioperative β-blockers after noncardiac surgery. The quality of the included studies was evaluated by the method recommended by the Cochrane Collaboration. Meta-analyses was conducted by using the Cochrane Collaboration’s RevMan software. Results Thirteen RCTs including 11 590 patients were included. The combined results of all studies showed cardioprotective effect of β-blockers (OR=0.64, 95%CI 0.50 to 0.80, P=0.000 1), with considerable heterogeneity among the studies (I2=57%). However, grouping the trials on the basis of maximal HR showed that trials where the estimated maximal HR was 100 bpm were associated with cardioprotection (OR=0.37, 95%CI 0.26 to 0.52, Plt;0.000 01) whereas trials where the estimated maximal HR was 100 bpm did not demonstrate cardioprotection (OR=1.13, 95%CI 0.81 to 1.59, P=0.48) with no heterogeneity (I2=0%). Conclusion The evidence suggests that effective control of HR is important for achieving cardioprotection and that administration of β-blockers does not reliably decrease HRs in all patients. Judicious use of combination therapy with other drugs may be necessary to achieve effective postoperative control of HR.
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.
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.