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 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.
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 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.
Objective To investigate the safety and efficacy of mitral valve replacement combined with cryoablation Maze surgery in patients with atrial functional mitral regurgitation (AFMR). Methods From January 2014 to June 2020, patients with AFMR who underwent mitral valve replacement in our department were enrolled. They were divided into two groups, a cryoablation Maze group who received cryoablation Maze surgery during mitral valve replacement, and a non-cryoablation Maze group who did not receive cryoablation Maze surgery. The baseline data, surgical data, efficacy, and prognosis between the two groups were compared. Results Finally 85 patients were enrolled. There were 16 males and 24 females with an average age of 58.65±6.86 years in the cryoablation Maze group, and 24 males and 21 females with an average age of 61.29±8.30 years in the non-cryoablation Maze group. There was no statistical difference in baseline data between the two groups (P＞0.05). The aortic occlusion time and extracorporeal circulation time of the cryoablation Maze group were longer than those of the non-cryoablation Maze group with statistical differences (P＜0.01). There was no statistical difference in postoperative ICU retention time, ventilator assistance time, length of hospital stay, intraoperative blood loss, drainage volume on the first day or occurrence rate of complications (temporary pacemaker application, electrical cardioversion, thoracic puncture drainage, hospitalization death) between the two groups (P＞0.05). At the time of discharge, postoperative 3-month, 6-month, 12-month, and 24-month, the maintenance rates of sinus rhythm in the non-cryoablation Maze group were statistically different from those of the cryoablation Maze group (P＜0.001). Compared with the non-cryoablation Maze group, the decrease values of left atrial diameter, left ventricular end-diastolic diameter, left ventricular end-systolic diameter and pulmonary artery systolic pressure were statistically different (P＜0.05). Postoperative cardiac function grading of both groups was grade Ⅰ or Ⅱ, which was significantly improved compared with preoperative level, but there was no statistical significance between the two groups (P＞0.05). There was no statistical difference in the incidence of adverse events during follow-up (P＞0.05). ConclusionCryoablation Maze surgery combined with mitral valve replacement is safe and effective in the treatment of AFMR patients, which is conducive to the recovery and maintenance of sinus rhythm, and is beneficial to the remodeling of the left atrium and left ventricle, the reduction of pulmonary systolic blood pressure, and the improvement of life quality of the patients.
Objective To compare the mid- and long-term clinical results of mitral valve plasty (MVP) and mitral valve replacement (MVR) in the treatment of functional mitral regurgitation (FMR). MethodsPatients with FMR who underwent surgical treatment in the Department of Cardiovascular Surgery of the General Hospital of Northern Theater Command from 2012 to 2021 were collected. The patients who underwent MVP were divided into a MVP group, and those who underwent MVR into a MVR group. The clinical data and mid-term follow-up efficacy of two groups were compared. Results Finally 236 patients were included. There were 100 patients in the MVP group, including 53 males and 47 females, with an average age of (61.80±8.03) years. There were 136 patients in the MVR group, including 72 males and 64 females, with an average age of (61.29±8.97) years. There was no statistical difference in baseline data between the two groups (P＞0.05). There was no statistical difference between the two groups in the extracorporeal circulation time, aortic occlusion time, postoperative hospital and ICU stay, intraoperative blood loss, or hospitalization death (P＞0.05), but the time of mechanical ventilation in the MVP group was significantly shorter than that in the MVR group (P=0.022). The total follow-up rate was 100.0%, the longest follow-up was 10 years, and the average follow-up time was (3.60±2.55) years. There were statistical differences in the left atrial diameter, left ventricular end-diastolic diameter, left ventricular end-systolic diameter and cardiac function between the two groups compared with those before surgery (P<0.05). The postoperative left ventricular ejection fraction in the MVP group was statistically higher than that before surgery (P=0.002), but there was no statistical difference in the MVR group before and after surgery (P=0.658). The left atrial diameter in the MVP group was reduced compared with the MVR group (P=0.026). The recurrence rate of mitral regurgitation in the MVP group was higher than that in the MVR group, and the difference was statistically significant (10.0% vs. 1.5%, P=0.003). There were 14 deaths in the MVP group and 19 in the MVR group. The cumulative survival rate (P=0.605) and cardiovascular events-free survival rate (P=0.875) were not statistically significant between the two groups by Kaplan-Meier survival analysis. Conclusion The safety, and mid- and long-term clinical efficacy of MVP in the treatment of FMR patients are better than MVR, and the left atrial and left ventricular diameters are statistically reduced, and cardiac function is statistically improved. However, the surgeon needs to be well aware of the indications for the MVP procedure to reduce the rate of mitral regurgitation recurrence.