Objective To investigate the long effect of nonpulsatile flow on changes of structure and function in pulmonary microcirculation and to identify the pulmonary reconstruction under this blood perfusion. Methods Canine models with nonpulsatile flow in the right lung was established, and sacrificed 6 months later. Compare endothelial nitric oxide synthase (eNOS) in vascular endothelium, apoptosis in smooth muscle cell with immunohistochemistry by streptavidinbioepidermmultienzyme complex methodes, and observe structural changes in pulmonary arterioles with optical microscope. Results The expression of eNOS in the right nonpulsatile flow perfusing lung was weaker as compared to the left lung （10 846.7±177.8 vs. 13 136.1±189.6;t＝2.240, P=0.040）, the fas was ber as compared to the left lung（14 254.1±217.1 vs. 11 976.7±195.7; t＝2.160, P=0.040）. The ratio of wall thichness/vessel diameter in the right lung（13.64%±12.80% vs. 14.96%±13.10%） and wall area/vessel area(46.40%±11.70% vs. 47.80%±12.20%) was lower as compared to the left lung(Plt;0.05). Conclusion Longterm nonpulsatile flow can decrease the expression of eNOS, contract the muscles in capillary net, and increase pulmonary vascular resistance. Moreover it canincrease the arteriole apoptosis, leading to vascular structure remodeling.
ObjectiveTo analyze the recovery rule of atrial contractility (AC) function after Maze Ⅳ procedure of valvular atrial fibrillation (AF).MethodsIn our hospital from March 2016 to April 2018, 103 patients who underwent cryoablation Maze Ⅳ procedure due to mitral valve lesions associated with persistent or long-term persistent AF were enrolled. There were 42 males and 61 females, with an average age of 58.5±9.1 years. Electrocardiogram and echocardiography were followed up at discharge and 1, 3, 6, 12 months after procedure. A multivariate Cox analysis of predictive factors for AC recovery was applied.ResultsAll the 103 patients were followed up for 1 year. The recovery rate of AC increased gradually after operation. It was not until 3 months after procedure that most of the right atrial contractility (RAC) was accompanied by synchronous recovery of the corresponding left atrial contractility (LAC, Kappa coefficient≥0.40, P<0.05). However, the coexistence of sinus rhythm (SR) and bilateral AC was not consistent well until 1 year after operation (Kappa coefficient≥0.40, P<0.05). One year after procedure, the recovery rates of SR and bilateral AC were 86.4% (89/103) and 66.0% (68/103) respectively. By Cox multivariate regression analysis, longer preoperative AF duration (P=0.040), larger preoperative left atrial diameter (LAD, P=0.003), and AC deletion 3 months after surgery (P=0.037) were predictive factors for AF recurrence in the middle and advanced stages (>3 months) after Maze surgery. At the same time, longer preoperative AF duration and larger preoperative LAD were also negative predictors of middle and late recovery of LAC and bilateral AC (All P<0.05). Receiver operating characteristic curve analysis showed that the best critical value of preoperative AF time and preoperative LAD for prediction of AC recovery was 37 months (sensitivity 99.6%, specificity 76.3%) and 60.5 mm (sensitivity 98.5%, specificity 78.9%), respectively.ConclusionThe recovery of AC after Maze procedure is a dynamic improvement process. Early recovery of AC is beneficial to the stable maintenance of SR in the future. Prolonged duration of AF and enlarged LAD have adverse effects on the outcome of Maze Ⅳ procedure.
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 investigate the restoration of left atrial function and its relationship with atrial fibrosis of patients after mitral valve replacement (MVR)and concomitant radiofrequency ablation (RFA)for atrial fibrillation (AF). MethodsClinical data of 32 patients with mitral valve disease and chronic AF who underwent surgical treatment in General Hospital of Shenyang Military Area Command from January to August 2010 were retrospectively analyzed in this cohort study. There were 11 male and 21 female patients with their age of 49.8±8.7 years. There were 14 patients with rheumatic mitral stenosis (MS), 8 patients with rheumatic MS and mitral regurgitation, and 10 patients with mitral valve prolapse. Preoperative AF duration was 3.6±4.6 years. All the patients received MVR and concomitant RFA for AF. According to the cutting off extent of left atrial fibrosis (10.9%), all the 32 patients were divided into 2 groups. There were 19 patients with more severe left atrial fibrosis ( > 10.9%)in group A and 13 patients with milder left atrial fibrosis ( < 10.9%)in group B. Immunohistochemistry was performed to examined left atrial fibrosis, and echocardiography was performed to examined the structure and function of left atrium. ResultsThere was no perioperative death. Cardiopulmonary bypass time was 84.6±22.6 minutes, aortic cross-clamping time was 47.6±15.6 minutes, and ICU stay was 3.2±1.5 days. All the 32 patients were followed up for longer than 6 months (1.3±0.6 years). The extent of left atrial fibrosis of the 32 patients was 4.8%-18.3% (10.7%±4.2%). There was no statistical difference in left atrial diameter (LAD), left atrial fractional area change (LAFAC)or mitral annular motion between group A and group B preoperatively and 3 months after surgery respectively (P > 0.05). At 6 month after surgery, LAD of group B was significantly smaller than that of group A (P < 0.05), late diastolic mitral annular velocity (Am)of group B was significantly higher than that of group A (P < 0.05), and there was also some improvement in LAFAC of group B compared with group A (P=0.067). Among the 32 patients, 28 patients (87.5%)restored sinus rhythm (SR)3 months after surgery, and 21 patients (65.6%)maintained SR longer than 6 months after surgery. Patients in group B were more likely to maintain SR than patients in group A (P=0.010). ConclusionImprovement of left atrial function can be observed 6 month after MVR and concomitant RFA for AF, which is related to the extent of left atrial fibrosis.
Objective Explore the effect of remote ischemic preconditioning (RIPC) on preoperative heart rate variability in patients with heart valves. Methods From January 2022 to July 2022, screening was conducted among 118 patients based on inclusion/exclusion criteria. Fifty-eight patients were excluded, and 60 patients participated in this trial with informed consent and were randomly divided into a RIPC group (n=30) and a control group (n=30). Due to the cancellation of surgery, HRV data was missing. 7 patients in the control group were excluded, and 5 patients in the RIPC group were excluded, 23 patients in the final control group and 25 patients in the RIPC group were included in the analysis. Comparison of relevant indicators of heart rate variability (standard deviation of NN interval (SDNN), standard deviation of mean value of NN interval in every five minutes (SDANN), mean square root of difference between consecutive NN intervals (RMSSD), percentage of adjacent RR interval>50 ms (PNN50), low frequency component (LF), high frequency component (HF) and LF/HF) at 8 hours in the morning on the surgical day between two groups of patients. Results There was no statistical difference in baseline characteristics between the two groups, and there was no significant difference in heart rate variability 24 hours before intervention (P>0.05). After the intervention measures were taken, the comparison of the results of heart rate variability at 8 hours on the day of operation showed that SDNN and SDANN of patients in the RIPC group were higher than those in the control group, with statistical differences (P<0.05). Conclusion RIPC can stabilize the preoperative heart rate variability of patients undergoing cardiac valve surgery.
Objective To evaluate the effect of left atrial enlargement on atrial myocardial fibrosis degree and levels of the angiotensinⅡ (AngⅡ)/Rac GTPase activating protein 1 (Rac1)/signal transducersand activators of transcription 3 (STAT3) signaling pathways expressing in patients with persistent atrial fibrillation and rheumatic heart disease (RHD). Methods From March to December 2011, 30 patients with RHD who underwent prosthetic valve replacement in our hospital were enrolled, including 16 males and 14 females, aged 42-70 (56.9±6.8) years. Twenty RHD patients with persistent atrial fibrillation as a research group and ten RHD patients with sinus rhythm as a control group (group A) underwent transthoracic echocardiography and right atrial appendage (RAA) tissue samples were obtained from these patients during mitral/aortic valve replacement operation. The research group according to left atrial diameter (LAD) was divided into two groups, ten patients in each group: a group B with LAD of 50–65 mm and a group C with LAD of LAD>65 mm. For each sample, histological examination was performed by hematoxylin-eosin and Masson’s trichrome staining. Light-microscopic pictures of atrial tissues samples were stained and tissue fibrosis degree in each group was analyzed. AngⅡ concentration was measured by enzyme linked immunosorbent assay. Rac1 and STAT3 were measured by western blotting. Results LAD was significantly greater in AF patients with RHD than in the control group. Hematoxylin-eosin staining demonstrated highly organized arrangement of atrial muscles in the control group and significant derangement in both group B and group C with reduced cell density and increased cell size. Moreover, Masson’s trichrome staining showed that atrial myocytes were surrounded by large trunks of collagen fibers in both group B and group C, but not in the group A. There was a positive correlation between atrial tissue fibrosis and LAD. AngⅡ content was positively correlated with LAD. Similarly, Rac1 and STAT3 protein levels were found considerably higher in the group C and group B than in the group A with excellent correlation to LAD. Conclusion In patients with RHD complicated with persistent atrial fibrillation, the degree of atrial fibrosis and the expression level of AngⅡ/Rac1/STAT3 signaling pathways significantly increase with the left atrialenlargement.
ObjectiveTo analyze factors affecting the recovery of postoperative left ventricular function in patients with valvular disease combined with heart failure with reduced ejection fraction [HFrEF, left ventricular ejection fraction (LVEF)<40%].MethodsThe clinical data of 98 patients with valvular disease combined with HFrEF who underwent surgeries in our hospital from January 2011 to June 2018 were retrospectively analyzed, including 75 males and 23 females aged 9-78 (55.3±11.9) years.ResultsA total of 15 patients were dead after the operation, including 4 deaths within 3 months and 11 mid-long-term deaths after the operation. Ninety-one patients were followed up for more than 6 months (10 months to 8.6 years). The postoperative cardiac function (NYHA) of 91 patients was classⅠ-Ⅱ, the LVEF of 18 (19.8%) patients increased more than 10%, that of 47 (51.6%) patients maintained at the preoperative level, and that of 26 (28.6%) patients decreased. Postoperative LVEF was more prone to recover in HFrEF patients with sinus rhythm before operation (P=0.038), valvular disease mainly in aortic valve (P=0.026), obvious reduction of left ventricular end diastolic diameter in early postoperative period (P=0.017), and higher systolic pulmonary artery pressure (SPAP) before operation (P=0.018). The risk factors for postoperative LVEF deterioration included large left atrium before operation (P=0.014), smaller left ventricle end systolic diameter before operation (P=0.003), and fast heart rate after operation (P=0.019). ConclusionMitral valve prolapse patients with obviously increased left ventricular diameter should receive operation as soon as possible. HFrEF patients with aortic valve disease should receive operation positively. The operation efficacy is satisfactory in the HFrEF patients with high SPAP.