Objective To investigate the effect of bone marrow mesenchymal stem cell (MSCs) transp1antation combined with transmyocardial drilling revascularization (TMDR) and degradable stent on myocardium revascu1arization after acute myocardial infarction(AMI), and to provide the experimental evidence for surgical treatment of myocardial infarction. Methods After established models of AMI, the 24 pigs were divided into four groups with random number table, 6 pigs each group. Control group: only established models of AMI; MSCs group: AMI immediately followed by MSCs implantation; TMDR combined with stent group: AMI followed by TMDR and absorbable basic fibroblast growth factor (bFGF) stent implantation; MSCs combined with TMDR and stent group: AMI followed by TMDR and absorbable bFGF stent implantation, and then MSCs implantation. Three months after operation, the infarcted areas and vessel density in infarcted zone were detected by histopathology method. Results Three months after operation, the histopathological examination showed that infarcted areas in MSCs group, TMDR combined with stent group, and MSCs combined with TMDR and stent group were decreased as compared with control group （27.9%±3.1% vs. 48.9%±2.7%，P=0.000；20.3%±1.7% vs. 48.9%±2.7%，P=0.000；12.5%±1.9% vs. 48.9%±2.7%，P=0.000）; and vessel density was further increased （8.4±1.2/HP vs.4.5±14/HP，P=CM(1583mm] 0.001；11.5±2.6/HP vs.4.5±1.4/HP，P=0.001;15.6±1.4/HP vs.4.5±1.4/HP，P=0.000）. Conclusion [CM)]MSCs transplantation combined with TMDR and absorbable bFGF stents implantation could significantly reduce the infarction areas, increase the vessel density. This method may enhance the efficacy of MSCs transplantation in acute cardiac infarction model, which provide a new ideas for the surgical treatment of myocardial infarction.
Objective To report a reliable left heart failure model in sheep using selected ligation of the diagonal branch. Methods Four male sheep were used. After a left anterior thoracotomy in sheep, the diagonal branch of coronary artery was ligated at a point approximately 40% of the distance from the apex to the base of the heart. Hemodynamic and echocardiography measurements were done preligation, 30 minutes and 7 days after the coronary artery of diagonal branch ligation. The electrocardiograms were obtained as needed, and cardiac function was also evaluated. The sheep were killed for postmortem examination of their hearts. Results Four sheep survived the experimental procedures. Comparing with before surgery, systemic arterial blood pressure and cardiac output were decreased, pulmonaryartery systolic pressure, pulmonary capillary wedge pressure and central venous pressure were increased at 30 min and 7 days after selected ligation of the coronary artery of diagonal branch; left ventricular end-diastolic dimension and left ventricular end-systolic dimension were increased; left ventricular ejection fraction and left ventricular fractional shortening were also decreased (Plt;0.05). Conclusion A reliable ovine model of left ventricular failure using selected ligation of the diagonal branch of the coronary artery can be achieved. This animal model is comparable to the clinical correlation.
Objective Engineer heart tissue (EHT) was constructed with mesenchymal stem cells (MSCs) and poly lacticacidCOglycolic acid (PLGA), and grafted onto the surface of myocardial infarction rats. We hypothesized that great omentum wrapping would increase EHT blood supply and ameliorate EHT microenvironment which is in favor of cardiac collagen remodling and heart function. We hope that omentun wrapped EHT could provide a valuable strategy for surgically myocardial infarction therapy. Methods MSCs were isolated from SD rats.Eight weeks after SD rats were subjected to left anterior descending (LAD) ligation, 18 rats were enrolled and divided into three groups, group A(n=6): great omentum wrapped MSCsPLGA EHT implantation; group B (n=6):MSCsPLGA EHT implantation; control group (n=6): the myocardial infarction; the sham group (n=6): only opened and closed chest, underwent LAD ligation, but no EHT implantation. Four weeks after transplantation, the following variables were evaluated: specimen stained with picrosirius red, left ventricle function evaluated by echocardiography, infarction ventricular wall motion by color kinesis (CK). Results Hearts of group A showed significantly less fibrosis than group B and control group (Plt;0.05). Infarction ventricular wall motion assessed by CK indicated significantly improvement in group A compared with group B and control group (Plt;0.05). Four weeks after transplantation, cardiac echocardiography showed left ventricle ejection fraction was lower in control group and group B compared with group A (Plt;0.05). Conclusion Transplantation of MSCsPLGA EHT with great omentum wrapping ameliorated infarction ventricular collagen remodeling, ameliorated infarction ventricular wall motion and preserved left ventricular function.
Objective To summarize the surgical experiences of ventricular septal rupture (VSR) after acute myocardial infarction (AMI) and investigate the time and methods of surgery. Methods From January 1999 to December 2008, 22 patients with VSR after AMI underwent surgical procedures. There were 17 male and 5 female with a age of 3978 years (mean age of 61.77 years). There were 18 cases with anterior VSR and 4 cases with posterior VSR, all of them combined with left ventricular aneurysm. Twentytwo cases underwent ventricular septal repair and aneurysm resection, 16 cases underwent coronary artery bypass grafting concomitantly with a graft of 2.11±1.57. Results There were 2 perioperative deaths (9.09%), 1 died of severe low cardiac output syndrome and 1 died of massive cerebral embolism. The other 20 cases were all cured and discharged. According to cardiac function classification from New York Heart Association（NYHA）, there were 4 cases in grade Ⅲ, 12 cases in grade Ⅱ and 4 cases in grade Ⅰ. Echocardiography showed that there were no VSR shunt and 2 cases with mild mitral valve regurgitation. Postoperative left ventricular enddiastolic diameter (LVEDD) reduced significantly compared with that before operation (50.27±5.33 mm vs. 57.94±6.79 mm, t=4.437, P=0.000). Sixteen cases were followed up, and the follow-up time was 3.24 months (13.9±6.5 months). Four cases were lost. There was no late death and cardiovascular event during following up. There were 11 cases in cardiac function classification (NYHA) grade Ⅱ and 5 in grade Ⅰ. Echocardiography showed that LVEDD reduced significantly (49.50±4.66 mm vs. 57.94±6.79 mm, t=5.041, P=0.000) and left ventricular ejection fraction (LVEF) increased significantly (55.08%±6.72% vs. 45.57%±11.31%, t=2.719, P=0.013)compared with those before operation. Conclusion VSR after AMI is one of the serious complications of AMI. Proper operation timing, perfect preoperative preparation, appropriate perioperative treatment, right surgical method and the avoidance of complications can effectively reduce the mortality and improve the prognosis.
ObjectiveTo investigate the surgical methods and efficacy of myocardial infarction combined with ventricular septal perforation.MethodsThe clinical data of 60 patients with myocardial infarction combined with ventricular septal perforation admitted to the Department of Cardiac Surgery, Beijing Anzhen Hospital, Capital Medical University, from 2009 to 2018 were retrospectively analyzed. There were 39 males and 21 females, aged 63.3±8.3 years.ResultsAmong the 60 patients, 43 (71.7%) patients were perforated in the apex, 11 (18.3%) in the posterior septum and 6 (10.0%) in the anterior septum. There were 24 (40.0%) patients of single coronary artery disease. Fourteen (23.3%) patients received intra-aortic balloon counterpulsation before surgery. The waiting time from ventricular septal perforation to surgery was 48.3 (3-217) d. All patients underwent ventricular septal perforation repair, among whom 53 (88.3%) patients received ventricular aneurysm closure or resection, and 49 (81.7%) patients received coronary artery bypass graft with an average of 2 distal anastomoses during the same period. Perioperative complications in the hospital included 8 (13.3%) deaths, 8 (13.3%) heart failure, 5 (8.3%) ventricular fibrillation, 3 (5.0%) pericardial tamponade, and 11 (18.3%) secondary thoracotomy and 11 (18.3%) residual shunt. Except for 8 patients who died in the hospital, the other 52 cured and discharged patients were followed up. The median follow-up time was 4.9 years. The 2-year and 5-year survival rate of the patients was 95.8%, and the 8-year survival rate was 89.0%. Major adverse cardiovascular events incidence was 19.2%, including 3 (5.8%) deaths, 5 (9.6%) heart failure, 2 (3.8%) myocardial infarction, and 4 (7.7%) cerebrovascular events.ConclusionFor patients with ventricular septal perforation after myocardial infarction, surgery is an effective treatment method. Although the perioperative mortality rate is high, satisfactory long-term results can be achieved by carefully choosing the operation timing and methods.
Objective To investigate the influence of infarcted myocardial construction by umbilical cord blood mesenehymal stem cells（MSC） with induced to myo-derived stem cells and implanted into infarcted myocardium. Methods Thirty-six adult mongrel canines were randomly divided into MSC transplant group and control group （18 each group）. Transplant group： the umbilical cord blood MSC differented to myo-derived stem cells induced by 5-azacytidine（5-aza） were implanted into the acute myocardial infarct site via the ligated left anterior descending （LAD） artery. Control group： administer the same volume of IMDM culture medium containing 0. 02% 4,6- diamidino-2-phenylindone （DAPI）. At 2, 4, 8 weeks after implantation, the change of basic myocardial construction and the distribution of desmin were observed by using Nagar-Olsen staining and immunohistology respectively. Results With less fusing, the arrangement of gelatine fibers and elastic fibers were in order in transplant group,and they were partly fused in control group by Nagar-Olsen staining. The expression of desmin of infarcted myocardial cell in transplant group was much higher than those in control group （P〈0. 01）. No significant difference was detected in the expression of desmin in normal site of both groups （P〉0. 05）. Conclusion There is an protective effect on the basic myocardial construction in infarcted myocardium after the umbilical cord blood MSC was differented to myo-derived stem cell by induced with 5-aza in vitro and implanted into the acute myocardial infarction.
Electrocardiogram (ECG) signal is an important basis for the diagnosis of arrhythmia and myocardial infarction. In order to further improve the classification effect of arrhythmia and myocardial infarction, an ECG classification algorithm based on Convolutional vision Transformer (CvT) and multimodal image fusion was proposed. Through Gramian summation angular field (GASF), Gramian difference angular field (GADF) and recurrence plot (RP), the one-dimensional ECG signal was converted into three different modes of two-dimensional images, and fused into a multimodal fusion image containing more features. The CvT-13 model could take into account local and global information when processing the fused image, thus effectively improving the classification performance. On the MIT-BIH arrhythmia dataset and the PTB myocardial infarction dataset, the algorithm achieved a combined accuracy of 99.9% for the classification of five arrhythmias and 99.8% for the classification of myocardial infarction. The experiments show that the high-precision computer-assisted intelligent classification method is superior and can effectively improve the diagnostic efficiency of arrhythmia as well as myocardial infarction and other cardiac diseases.
ObjectiveTo improve and assess the method of establishing myocardial infarction model in New Zealand rabbits. MethodsA total of 60 New Zealand rabbits were randomly divided into two groups:the left anterior descending coronary artery was ligated in a LAD group (n=30); the left circumflex coronary artery was ligated in a LC group (n=30). Electrocardiogram (ECG), ultrasound cardiogram (UCG), hemodynamics and histology procedures were performed to detect the changes of cardiac structure and function after myocardial infarction induced by LAD and LC ligation. ResultsSuccess rate of the LC group was significantly higher than that in the LAD group (P < 0.01), but the survival rate in the LC group was slightly lower than the LAD group (P < 0.05); ECG within 24 h and 1 week after surgery showed that the average values of ST segment elevation in the LC group were significantly higher than that in the LAD group (P < 0.05); UCG and hemodynamics results showed cardiac function in the LAD group did not decrease significantly (P > 0.05). In contrast, cardiac function in the LC group were significantly decreased (P < 0.05). Histopathologic analysis showed that the area of myocardial infarction in the LC group was significantly larger than that in the LAD group (P < 0.01). ConclusionThe myocardial infarction induced by the left circumflex coronary artery ligation is more consistent than that induced by the left anterior descending coronary artery ligation, suggesting that the former is a more appropriate experimental model for evaluations.
Abstract: Objective To investigate the relationship between graft flow and incidence of perioperative myocardial infarction (MI) in coronary artery bypass grafting (CABG). Methods Between January 2010 and June 2010, 58 consecutive patients with coronary artery disease who underwent offpump CABG in the First Hospital of Peking University were enrolled in this study. An anastomosis between left internal mammary arteries (LIMA) and left ant erior descending coronary artery (LAD) were performed. And saphenous vein (SV) graft s were used as bypass grafts. Graft flow was measured intraoperatively using a transi t time flowmeter, and the total graft flow of each patient was calculated as a parameter of myocardial revascularization. The 58 patients were divided into a MI group and a nonMI group retrospectively. There were 11 patients in the MI group, including 7 males and 4 females, with an average age of 67.4±10.3 years.There were 47 patients in the nonMI group, 38 males and 9 females, with a mean age of 633±99 years. The graft flow of the two groups was tested and compared, and the preoperative variables were compared. Results There was no statistically significant difference in operation time (205.4±59.6min versus 1834±32.4 min, t=1.691, P=0.096) between the two groups. Therewere also no statistical differences in the average number of grafts (3.00±1.00 branches versus 2.96±0.78 branches, t=0.154, P=0878) or LIMALAD flow (1540±11.37 ml/min versus 16.50±10.83 ml/min, t=0.301, P=0.764) between the two groups. However, a significant difference was found in the total graft flow between the two groups (41.03±19.50 ml/min versus 64.09±32.44 ml/min, t=2.254, P=0.028), with lower total graft flow in the MI group. Further analysis showed [CM(159mm]that a total graft flow lt;48.5ml/min was a risk factor for MI (odds ratio 4.706, 95% confidence interval 1.099 to 20.147). Conclusion Total graft flow could be used to predict the occurrence of perioperative myocardial ischemia, as there is a high probability of MI for patients with a total graft flow of less than 48.5 ml/min.
Abstract: Objective To observe the changes in morphology, structure, and ventricular function of infarct heart after bone marrow mononuclear cells (BMMNC) implantation. Methods Twenty-four dogs were divided into four groups with random number table, acute myocardial infarction (AM I) control group , AM I-BMMNC group , old myocardial infarct ion (OMI) control group and OM I-BMMNC group , 6 dogs each group. Autologous BMMNC were injected into infarct and peri-infarct myocardium fo r transplantation in AM I-BMMNC group and OM I-BMMNC group. The same volume of no-cells phosphate buffered solution (PBS) was injected into the myocardium in AM Icontrol group and OM I-control group. Before and at six weeks of cell t ransplantation, ult rasonic cardiography (UCG) were performed to observe the change of heart morphology and function, then the heart was harvested for morphological and histological study. Results U CG showed that left ventricular end diastolic dimension (LV EDD) , left ventricular end diastolic volume (LVEDV ) , the thickness of left ventricular postwall (LVPW ) in AM I-BMMNC group were significantly less than those in AM I-control group (32. 5±5. 1mm vs. 36. 6±3. 4mm , 46. 7±12. 1m l vs. 57. 5±10. 1m l, 6. 2±0. 6mm vs. 6. 9±0. 9mm; P lt; 0. 05). LVEDD, LVEDV , LVPW in OM I-BMMNC group were significantly less than those in OM I-control group (32. 8±4. 2 mm vs. 36. 8±4. 4mm , 48. 2±12. 9m l vs. 60.6±16.5m l, 7. 0±0. 4mm vs. 7. 3±0. 5mm; P lt; 0. 05). The value of eject fraction (EF) in OM I-BMMNC group were significantly higher than that in OM I-control group (53. 3% ±10. 3% vs. 44. 7%±10. 1% ). Compared with their control group in morphological measurement, the increase of infarct region thickness (7. 0 ± 1. 9mm vs. 5. 0 ±2.0mm , 6.0±0. 6mm vs. 4. 0±0. 5mm; P lt; 0. 05) and the reduction of infarct region length (25. 5±5. 2mm vs. 32. 1±612mm , 33. 6±5. 5mm vs. 39. 0±3. 2mm , P lt; 0. 05) were observed after transplantation in AM I-BMMNC group and OM I-BMMNC group, no ventricular aneurysm was found in AM I-BMMNC group, and the ratio between long axis and minor axis circumference of left ventricle increased in OM I-BMMNC group (0. 581±0. 013 vs. 0. 566±0.015; P lt; 0. 05). Both in AM I-BMMNC group and OM I-BMMNC group, fluorescence expressed in transplantation region was observed, the morphology of most nuclei with fluorescencew as irregular, and the differentiated cardiocyte with fluorescence was not found in myocardium after transplantation. The histological examination showed more neovascularization after transp lantation both in AMI and in OM I, and significant lymphocyte infiltration in AM I-BMMNC group. Conclusion BMMNC implantation into infarct myocardium both in AMI and OMI have a beneficial effect, which can attenuate deleterious ventricular remodeling in morphology and st ructure, and improve neovascularization in histology, and improve the heart function.