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 myocardial protective effects of Del Nido cardioplegia and analyze its advantages in adult cardiac surgery. Methods We retrospectively analyzed the clinical data of 96 adult patients undergoing cardiac valve surgery who received Del Nido cardioplegia (a DNC group) from June 2016 to January 2017 in our hospital. There were 44 males and 52 females with a mean age of 51.36±13.31 years. Meanwhile 96 patients who received conventional cardioplegia were recruited as a control group (a CTC group) and there were 53 males and 43 females with a mean age of 52.91±10.95 years. Cross-clamping time, cardiopulmonary bypass (CPB) time, total volume of and transfusion frequency of cardioplegia, the rate of spontaneous defibrillation, red blood cell transfusion and vasoactive-inotropic score at postoperative 24 hours (VIS 24) were recorded. Results No significant difference was found in age, body weight, ejection fraction, hematokrit, CPB time and cross-clamping time between the DNC group and CTC group. There was no significant difference in the rate of spontaneous defibrillation, VIS 24, cardiac enzymes and cardiactroponin I and length of ICU stay between the two groups. The total volume and transfusion frequency of cardioplegia, perioperative blood transfusion were lower in the DNC group. There was no new atrial fibrillation or in-hospital death in the two groups. Conclusion Del Nido is a good myocardial protection solution in adult cardiac valve surgery, and requires less static preload volume and reduceshemodilution and perioperative blood transfusion.
ObjectiveTo compare the myocardial protective effect of HTK solution and St.ThomasⅡ(STH) solution in immature rabbit myocardium at different cardiac arrest time. MethodsAccording to cardioplegia and cardiac arrest time, 32 immature New Zealand white rabbits (aged 2-3 weeks) were randomly divided into four groups. A group SO (8 rabbits) underwent 1 hour cardiac arrest with STH solution, a group ST (8 rabbits) underwent 2 hours cardiac arrest with STH solution, a group HO (8 rabbits) underwent 1 hour cardiac arrest with HTK solution, a group Ht (8 rabbits) underwent 2 hours cardiac arrest with HTK solution. Compare the myocardial protective effect of HTK and STH solution in immature myocardium at different cardiac arrest time. ResultsThe Langendorff models were successfully established in 30 cases (8 cases in the group SO and HO, 7 cases in the group ST and HT). There were no statistical differences in hemodynamics and myocardial enzyme (CK-MB, LDH) (P > 0.05), but HTK solution reduced the activity of nitric oxide synthase (NOS) and content of malonaldehyde (MDA) and NO, maintained high activity of superoxide dismutase (SOD) and Ca2+-ATPase (P < 0.05), performed more effective myocardial protection for immature myocardium. ConclusionHTK solution has more effective myocardial protection for immature myocardium than STH solution does, but STH solution still has good outcomes within short cardiac arrest time (1h).
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.
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.
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.
ObjectiveTo explore clinical outcomes of papaverine via the aortic root under cardiopulmonary bypass (CPB) in coronary artery bypass grafting. MethodsA total of 263 patients with coronary artery disease underwent CPB in coronary artery bypass grafting in Beijing Anzhen Hospital from August 2003 through December 2014 were included. According to whether or not they received papaverine perfusion via the aortic root in the first perfusion during CPB, all the 263 patients were divided into two groups including an intervention group and a control group. There were 176 patients in the intervention group including 109 males and 67 females with their average age of 64.37±23.54 years. They received aortic root perfusion of 60 mg papaverine diluted into 20 ml during the first perfusion, and repeated aspiration was performed 8 to 10 times in CPB when the heart beat weak. In the control group, there were 87 patients including 55 males and 32 females with their average age of 65.98±29.13 years. Patients in the control group received routine procedures of CPB except papaerine perfusion. Clinical effectiveness was compared between the two groups. ResultsThere was no in-hospital death. CPB supporting time after heart re-beating (9.58±3.21 min vs. 19.74±5.67 min, t=-1.133, P=0.000), dopamine usage 3.12±1.27 μg/(kg·min) vs. 4.98±2.53 μg/(kg·min),t=-0.913, P=0.031), epinephrine usage 0.018±0.009 μg/(kg·min) vs. 0.047±0.011 μg/(kg·min), t=-0.811, P=0.018) and nor epinephrine usage 0.021±0.011 μg/(kg·min) vs. 0.037±0.010 μg/(kg·min), t=-0.823, P=0.019) of the intervention group were significantly shorter or lower than those of the control group. Automatic heart re-beating rate of the intervention group was significantly higher than that of the control group (98.86% vs. 70.11%,t=-1.372, P=0.000). A total of 176 patients in the nitroglycerin group were followed up for 6-121 months, and 16 patients were lost during follow-up. During the follow-up period, 6 patients were hospitalized for cardiac events, and 2 died in 29 months and 103 months after surgery, and 9 died from cardiac events. ConclusionFor the patients undergoing on-pump coronary artery bypass grafting, some myocardial protection strategies including papaverine perfusion via the aortic root in the first perfusion, 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 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.
From aortic declamping to weaning from cardiopulmonary bypass (CPB), myocardium needs recovery not only from surgical and ischemia/reperfusion injury, but also of its full performance of pumping function as quickly as possible. In the early period of resuming myocardial perfusion, coronary blood flow should be increased, but ventricular volume overload, large dosage of adrenaline and isoprenaline, and high-energy defibrillation should be avoided. Thenappropriate management according to cardiac function and ECG changes is needed for successful weaning from CPB.