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.
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.
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.
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.
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.
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).
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.
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.
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 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.