Abstract： Objective To study the changes of the cyclic adenosine monophosphate (cAMP) and protein kinase A (PKA) expression of isolated rat hearts after diazoxide preconditioning (DPC), and to explore the possible mechanism of cAMP signaling pathway in myocardial protection by DPC. Methods Isolated working heart Langendorff perfusion models of 40 Wistar rats were set up and were divided randomly into four groups. For the ischemia reperfusion injury(I/R) group (n=10), 30 min of equilibrium perfusion was followed by a 60 min reperfusion of KrebsHenseleit (K-H) fluid. The DPC group (n=10) had a 10 min equilibrium perfusion and two cycles of 5 min of 100 μmol/L diazoxide perfusion followed by a 5 min diazoxidefree period before the 30 min ischemia and the 60 min reperfusion of K-H fluid. The blank control group (control group, n=10) and the Dimethyl Sulphoxide(DMSO) group (n=10) were perfused with the same treatment as in the DPC group except that diazoxide was replaced by natriichloridum and DMSO respectively. The activity of creatine kinase (CK) in coronary outflow, the activity of malonyldialdehyde (MDA) and superoxide dismutase (SOD) in myocardium were detected. And the scope of myocardial infarction and the concentrations of myocardial cAMP and PKA were also assessed. Results Compared with the I/R group, the level of MDA for the DPC group decreased significantly (8.28±2.04 nmol/mg vs. 15.52±2.18 nmol/mg, q=11.761,Plt;0.05), the level of SOD increased significantly (621.39±86.23 U/mg vs. 477.48±65.20 U/mg, q=5.598,Plt;0.05). After a 30 min reperfusion, compared with the I/R group, the content of CK decreased significantly (82.55±10.08 U/L vs. 101.64±19.24 U/L, q=5.598, Plt;0.05) and the infarct size reduced significantly (5.63%±9.23% vs.17.58%±5.76%, q=6.176,Plt;0.05) in the DPC group. The cAMP concentration in the DPC group was much higher than that in the I/R group (0.64±0.07 pmol/g vs. 0.34±0.05 pmol/g, q=14.738,Plt;0.05), and PKA concentration was also much higher than that in the I/R group ［17.13±1.57 pmol/(L·min·mg) vs. 12.85±2.01 pmol/(L·min·mg), Plt;0.05］. However, there were no significant differences between the I/R group, DMSO group and the control group in the above indexs (Pgt;0.05). Conclusion DPC significantly improves the releasing of cAMP and PKA, decreases oxygen free radicals, and relieves myocardial ischemia reperfusion injury. The cAMP signaling pathway may be involved in triggering the process of myocardial protection mechanisms of DPC.
Objective To analyze early and midterm outcomes and summarize clinical experience of mitral valve repair with artificial chordae for degenerative mitral regurgitation （MR）. Methods Clinical data of 78 patients with degenerative MR who underwent mitral valve repair with Gore-Tex artificial chordae from October 2008 to December 2011 in General Hospita1 of Shenyang Military Command were retrospectively analyzed. There were 47 male patients and 31female patients with their age of 52.7±9.6 years，who all had degenerative MR. Operation techniques included simple GoreTex artificial chordae replacement in 15 patients，artificial chordae replacement plus quadrangular resection of the posterior leaflet in 58 patients，artificial chordae replacement plus quadrangular resection of the posterior leaflet and Sliding technique in 5 patients. One to three （2.15±1.05） Gore-Tex artificial chordae were used for each patient，and annuloplasty ring was used for all the patients. Thirty-nine patients underwent concomitant tricuspid valvuloplasty. Intraoperative transesophagealechocardiography showed none obvious MR in 62 patients，trivial MR in 13 patients and mild MR in 3 patients. All thepatients were followed up after discharge. Echocardiography was used to evaluate heart function and MR degree duringfollow-up. Results There was no in-hospital death in this group. Postoperative complications included sinus bradycardiain 5 patients，supraventricular tachycardia in 8 patients，late cardiac tamponade in 1 patient，and permanent pacemakerimplantation in 1 patient. Seventy patients were followed up for 1-2 years with the follow-up rate of 89.74% （70/78）. Duringfollow-up，1 patient died of cerebral embolism 13 months after discharge，and all the other patients remained alive. There were 60 patients with NYHA classⅠand 9 patients with NYHA classⅡ. Echocardiography at 1 year after dischargeshowed that left atrial diameter，left ventricular end-diastolic diameter，left ventricular end-systolic diameter，and pulmonary artery systolic pressure were significantly smaller or lower than preoperative values （P＜0.05），left ventricular ejection fraction （68.00%±7.00% vs. 55.00%±6.00%） and cardiac output were significantly higher than preoperative values（P＜0.05），and MR degree （ratio of regurgitation beam area and left atrial area） was significantly reduced compared with preoperative MR degree （3.45%±5.56% vs. 39.55%±9.86%，P＜0.05）. No artificial chordae rupture was found. There were47 patients without MR and 22 patients with trivial MR during follow-up. Conclusion Gore-Tex artificial chordae replacement is a safe and effective surgical technique for the treatment of degenerative MR.
ObjectiveTo evaluate the feasibility to use ultrasonic cardiac output monitoring (USCOM) for patients after coronary artery bypass grafting. MethodsClinical data of 32 patients undergoing off-pump coronary artery bypass grafting in General Hospital of Shenyang Military Region between April and June 2013 were retrospectively analyzed. There were 17 male and 15 female patients with their age of 46-76 (63.2±7.6) years. USCOM and pulmonary artery catheterization (PAC) were used to measure cardiac output (CO) synchronously,and the results were compared between USCOM and PAC. ResultsSixty-four pairs of data were collected from those 32 patients. No adverse event was observed with either USCOM or PAC. Mean CO was 4.27±0.92 L/min with USCOM and 4.49±0.75 L/min with PAC respectively,which were not statistically different (P=0.12) but significantly correlated (r=0.84,P<0.001). ConclusionThere is close correlation between USCOM and PAC for CO measurement. USCOM can not only measure CO accurately,but also has the advantages of being noninvasive,easy to perform and low cost.
ObjectiveTo investigate the influence of 6% hydroxyethyl starch (HES, 130/0.4)on blood coagulation of patients after off-pump coronary artery bypass grafting (opCAB)by thromboelastography (TEG). MethodsOne hundred patients undergoing elective opCAB in Department of Cardiovascular Surgery, General Hospital of Shenyang Military Area Command between May and July 2013 were enrolled in this study. All the patients were randomly divided into 2 groups using random number table method with 50 patients in each group. In the experimental group (G1 group), there were 27 males and 23 females with their age of 64.9±4.4 years, who received intravenous 6% HES (130/0.4)20 ml/kg in 4 hours postoperatively. In the control group (G2 group), there were 31 males and 19 females with their age of 63.1±5.8 years, who received intravenous lactated ringers 20 ml/kg in 4 hours postoperatively. After postoperative ICU admission, full blood count, coagulation tests and TEG were examined. Chest and mediastinal drainage was recorded at 6 hours and 24 hours postoperatively. ResultsThere was no statistical difference in chest and mediastinal drainage 24 hours postoperatively between the 2 groups (591.7±171.7 ml vs. 542.4±174.0 ml, P > 0.05). None of the patients received reexploration for bleeding. There was no statistical difference in hemoglobin, hematocrit, platelet count or traditional coagulation index between the 2 groups (P > 0.05). TEG showed no significant change in coagulation time after intravenous fluid infusion in either group. Reaction time was slightly extended in both groups, but there was no statistical difference in reaction time between the 2 groups (P > 0.05). Maximum amplitude (MA)of G1 group was significantly decreased after intravenous fluid infusion (55.9±10.0 mm vs. 62.8±7.9 mm, P < 0.05), but still within the normal range. There was no significant change in MA after intravenous fluid infusion in G2 group. ConclusionIntravenous infusion of 6% HES (130/0.4)20 ml/kg can reduce platelet function and clot strength, but does not significantly increase postoperative chest or mediastinal drainage, or the incidence of postoperative reexploration for bleeding. It's safe to administer 6% HES (130/0.4)for patients after OPCAB.
ObjectiveTo investigate acute physiologic and chronic health evaluation Ⅱ(APACHE Ⅱ) score system for severity evaluation and prognosis prediction of patients undergoing cardiac surgery. MethodsA total of 3 566 patients who were admitted in ICU after cardiac surgery in the Department of Cardiovascular Surgery of General Hospital of Shenyang Military between December 1, 2011 and August 31, 2013 were enrolled in this study. There were 1 873 males and 1 693 females with their average age of 45.8±23.7 years (range, 10 days to 82 years). All the patients were evaluated with APACHE Ⅱ and expected mortality was calculated. Receiver operating characteristic(ROC) curve was drawn to compare expected and actual mortality and evaluate predictive value of APACHE Ⅱ. ResultsA total of 3 373 patients survived the operation, and 193 patients died postoperatively with the mortality of 5.41%. The area under the ROC curve was 0.917 (P=0.000) with 95% confidence interval of[0.885,0.949]. The cut-off point of APACHE Ⅱ was 15.50, with a sensitivity of 80.3%,a specificity of 95.6%,an accuracy rate of 79.5%,a positive predictive value of 86.9%,and a negative predictive value of 93.1%. Expected and actual mortality increased with increasing APACHE Ⅱ,which were both positively correlated. ConclusionAPACHE Ⅱ score system can be used to evaluate severity and predict prognosis of patients undergoing cardiac surgery, which provides reference for rational utilization of ICU resource.