ObjectiveTo study the changes of levels of α subunits of stimulatory (Gsα) and inhibitory guanine nucleotide binding protein (Giα) in newborn guinea pig (0 2 days old) myocardium undergoing global ischemic reperfusion, and influences on the changes by St.Thomas Ⅱ and cold blood cardioplegic solution.MethodsThirty newborn guinea pigs were randomly assigned to three groups. GroupⅠ ( n = 10): the newborn hearts suffered by hypothermic global ischemia; group Ⅱ( n =10): the newborn hearts arrested by St. Thomas Ⅱ , and group Ⅲ ( n = 10): the newborn hearts arrested by cold blood cardioplegic solution. Levels of Gsα and Giα were investigated with Western blot analysis.ResultsNo differences of levels of Gsα and Giα were found in three groups before ischemia ( P gt;0.05). The level of Gsα after ischemia was significantly decreased than before ischemia in groupⅠand group Ⅱ ( P lt; 0 01), whereas no pronounced changes in group Ⅲ ( P gt;0.05) were noted after ischemia. The level of Gsα in group Ⅲ was not significantly changed after reperfusion compared with before ischemia( P gt;0 05), and it was much higher than those in groupⅠand group Ⅱ ( P lt; 0 01). Level of Giα was found not markedly changed in group Ⅲ after reperfusion compared with that before ischemia, but was notable higher in groupⅠand group Ⅱ( P lt;0.01). ConclusionsSignificant decrease of level of Gsα, whereas marked increase of level of Giα are found in myocardium of newborn guinea pig undergoing hypothermic (20℃) ischemic reperfusion. No impact of St. Thomas Ⅱ on these changes is verified, but recovery to the level of Gsα and Giα before ischemia is achieved by cold blood cardioplegic solution after ischemia and reperfusion. Unbalance between Gsα and Giα is the one of the mechanisms of ischemic reperfusion injury for immature myocardium.
Objective\ In order to assess and evaluate the clinical results of cold blood cardioplegia and intermittent cross clamping as myocardial preservation in coronary artery bypass grafting(CABG).\ Methods\ According to the management methods, 2 013 cases for elective, isolated CABG were divided into two groups at St.George’s Hospital, London.Cold blood cardioplegia group: 596 patients treated with cold blood cardioplegia, and hypothermic ventricular fibrillation group: 1 417 patients treated with intermitt...
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.
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.