| Part one. The establishment of the pressure overload in rats induced reduction of left ventricular diastolic function model.Objective:Research and establish the methods of animal model which concerned with the reduction of left ventricular diastolic function.Methods:The researchers used eighty8-week-old Wistar rats and randomly divided them into control and experimental group. Each group got40rats. The experimental group made an anesthesia by giving intraperitoneal injection of10%chloral hydrate (3ml/100mg). Then exposing and freeing the abdominal aorta through the left upper abdominal incision into the abdominal cavity. After determining the branch of the left renal artery, fastening the abdominal aorta together with the8Gauge needled (diameter0.8mm) by a silk thread. Reaching the abdominal aortic lumen constricted lumen after the needle was picked out. The control group made the anesthesia and then just implemented the free abdominal aorta without constricted part. After the operation, the researcher observed the animal’s diet, activity, their ability of responding to the outside world, etc. Recording their significant declined time in activity, cough, and difficult breathing. In keeping the2nd week, the4th week, the6th and the8th week, giving the animal hemodynamic among the same number of rats which were randomly selected from the control group and experimental group. With the right common carotid artery, the researchers connected the BL-410biological and functional experimental system (Chengdu Tai Meng Technology Co. Ltd.) through the poly plastic tube.Then the researchers gave the mean arterial blood pressure test (MAP), left ventricular systolic pressure (LVSP), left ventricular end diastolic pressure (LVEDP), left ventricular pressure increase rate (+dp/dtmax), left ventricular pressure decline rate (-dp/dtmax). After test, the rats sacrificed, and then their left ventricular tissue were picked, weighted and calculated the left ventricular mass index (LVMI). The cardiac tissue were kept in a-80℃refrigerator. In the endpoint, unified by RT-PCR method to detect the ventricular SERCA and PLB mRNA, and compared the control group at each time point and experimental group which had differences in expression levels. The remaining10%of myocardial tissue was fixed in formalin. Then embedded in a unified endpoint and sliced. HE myocardial morphological changes were observed, and the number of myocardial cells per high power field in the cross-section of left ventricular papillary muscles was counted. The researchers consolidated the result of the hemodynamic and myocardial morphology as an evaluation criterion of a successful model. Statistical Package for all data handled by SPSS13.0. Measurement data as mean±standard deviation, using t test; statistics to P<0.05as significantly different, P<0.01as significant statistical difference.Results:General observation:after one week, each group appeared apathetic, reduced activity, feeding and water intake reduction. Those situations were improved after a week. In the2nd and4th week, there is no significant difference between the experimental group and control group in the activities of eating situations. At the6th week, animals in the experimental group turned to be less active, less diet, and less weight than the control group (298.11±50.85vs.334.29±46.09)(P<0.05). After the6th week, animals in experimental group gradually got the symptoms about cough, breathing speed up and activity decreased significantly. At the endpoint of the8th week, animals in the experimental group reflected slowly to the outside world, had no interest in eating. Some animal died (20%), and their weight is less than the control group (289.58±45.23vs.349.56±38.24)(P<0.05). After the operation, the rats in experimental group died four, and the survival rate was90%. Among them, two died within1day after surgery and two died of breathing difficulties after8weeks. There is no death in the control group. According to the hemodynamic monitoring results, at each time point the experimental group had a higher sustainment on the MAP and LVSP. And the diastolic function parameters in this group appeared progressive change. What’s more, the systolic function parameters declined at the6th week. At the2nd week, comparing with the control group, the experimental group’s-dp/dtmax decreased (4.32±0.27vs.5.13±0.21)(P<0.05), and there is no other difference; at the4th week, the experimental group’s-dp/dtmax decreased dramatically (3.64±0.30vs.5.33±0.28)(P<0.01), the LVEDP increased significantly (15.45±2.56vs.5.90±2.46)(P<0.01), and there is no other difference; at the6th week, the experimental group’s-dp/dtmax decreased obviously (3.42±0.32vs.5.29±0.34)(P <0.01), while the LVEDP increased significantly (19.89±3.28vs.5.67±2.58)(P <0.01), and the+dp/dtmax decreased (5.98±0.31vs.6.34±0.38)(P<0.05); at the8th week, in the experimental group the-dp/dtmax decreased dramatically (2.04±0.31vs.5.41±0.39)(P<0.01), and the LVEDP increased significantly (24.34±4.08vs.5.67±2.58)(P<0.01), and the+dp/dtmax decreased obviously (4.50+0.21vs.6.21±0.31)(P<0.01). The LVMI conditions:compared with the control group, the experimental group had no difference in2weeks; in the4th week it increased (2.69±0.18vs.2.33±0.20); in the6th week it increased significantly (2.65±0.21vs.2.42±0.16); in the8th week, it increased dramatically (2.96±2.39±0.19)(P<0.01). The Pathological examination revealed progressive myocardial damage:in the control group and the experimental group within2weeks, the myocardial cell was integrity and arranged in order; in the4-week-experimental group, the cardiac hypertrophy occurred and the gap widened slightly, what’s more, the occasionally spotty necrosis and interstitial edema happened; in the6-week-experimental group, there was obviously cardiac hypertrophy, and the nuclei was so big that got infection, what’s more the cross-sectional area increased and there was scattered punctate myocardial necrosis, then the myocardial cell in the high power field was less than the control group(19.78±3.36vs.25.34±5.04)(P<0.05); in the8-week-experimental group, showing myocardial cells significantly increased and the arrangement was disordered, then the gap widened and the showing sheet myocardial necrosis occurred, what’s more, the myocardial cell in the high power field was less than the control group(18.16±3.24vs.28.35±3.25)(P<0.05). There were large amount of inflammatory cells. PLB expression showed that there was no significant difference in control and experimental groups. According to the SERCA2a expression, in the2nd week the experimental group and control group had no significant difference; in the4th week, the experimental group was less than the control group (CT value of28.15±0.84vs.26.14±0.51)(P<0.05); in the6th week, the experimental group was less than the control group (CT value of29.02±1.27vs26.50±0.89)(P<0.05); in the8th week, the experimental group was less than the control group (CT value of32.09±1.38vs.27.25±1.24)(P<0.01) Conclusion:8-week-old Wistar rats’left ventricular diastolic function declined within2-8weeks after having the upper kidney abdominal aortic coartation. The2nd showed impaired LV active relaxation; the4th week was the stage that the filling pressure was increased; in the6th week was the stage that the restrictive filling barriers; In the8th week, the heart failure performed. The main factor of effecting the myocardial calcium cycling-SERCA2a expression may be mainly the inhibition of left ventricular diastolic dysfunction in the late term.Part Two. The correlation between hemodynamic with Ultrasound or Markers of heart failure during evaluat left ventricular diastolic function in the modelObjective:To discuss the evaluation of ultrasonic grading in left ventricular diastolic function of the feasibility of reduction; discuss the serum NT-proBNP levels and diastolic function of the decreased correlation; to establish non-hemodynamic methods to evaluate the left ventricular diastolic function of the reduction model of.Methods:Using upper renal abdominal aortic coarctation method to establish the left ventricular diastolic dysfunction in a30-rat-model, and establish the control group in other30ones. After2weeks,4weeks and6weeks of reduction in abdominal aortic rings, the researchers used the application of Philips iE33color Doppler to select S12-4high-frequency probe and then made the echocardiography to the rats in the experimental group and control group. The researchers used2-D ultrasound, M-mode ultrasound recording of left ventricular posterior wall thickness (LVPWD), interventricular septum thickness (IVSD), left ventricular end diastolic diameter (LVEDD), left ventricular end systolic diameter (LVESD), left a trial end systolic diameter (LADs), Left ventricular ejection fraction (LVEF), left ventricular fractional shortening (FS) and cardiac output (CO); and calculated the left ventricular mass(LVmass) according to the formula; then the researchers used the mitral diastolic flow Doppler spectrum Early peak flow velocity (E); Doppler tissue imaging (DTI) at the mitral annulus peak systolic myocardial tissue velocity (Sm), peak early diastolic velocity (Em), late diastolic peak velocity (Am); calculation of Em/Am and E/Em. After the ultrasound examination, the researchers immediately made the hemodynamic monitoring with the method that the first part mentioned. The Detection indicators included mean arterial pressure (MAP), left ventricular systolic pressure (LVSP), left ventricular end diastolic pressure (LVEDP), left ventricular pressure increase rate (+dp/dtmax), left ventricular pressure decline rate (-dp/dtmax). The researchers drew lml blood before the hemodynamic via the right common carotid artery, and then got the supernatant after centrifugation. Keeping it in a-80℃refrigerator to store and in the end point, the researchers unified to ELISA, detect serum NT-pro BNP levels. Statistical Package for all data handled by SPSS13.0. Measurement data as mean±standard deviation, using t test; statistics to P<0.05as significantly different, P<0.01as significant statistical difference.Results:Hemodynamic results suggested that the establishment of model is successful. The2-dimensional and M-mode ultrasound examination showed that the experimental group got the gradually thickened ventricular and the left atria diameter increased. Specifically speaking, in the2nd week, there is no difference in the experimental group and control group between the various sets of data; in the4th week compared with the control group, the experimental group’s LVPWD thickened (2.50±0.31vs.2.15±0.27) mm,(P<0.05); LADs broadened (3.25±0.32vs.2.84±0.14) mm,(P<0.05); in the6th week, the experimental group’s LVPWD became significantly thicker (2.82±0.40vs.2.30±0.26) mm,(P<0.01); LVEDD turned larger (6.57±0.37vs.5.82±0.39) mm,(P<0.05); IVSD thickened (2.39±0.28vs.2.06±0.13) mm,(P<0.05); LADs was obviously enlarged (3.43±0.32vs.2.79±0.41) mm,(P<0.01). The detection of left ventricular diastolic function indicators could appear on behalf of progressive reduction of left ventricular diastolic changes. Specifically speaking, in the2nd week, compared with the control group, the experimental group’s Em slow (8.12±0.58vs.9.65±0.65),(P<0.05). In the4th week, the experimental group’s E increased faster (114.7±5.8vs.91.9±6.7) cm/s,(P<0.05), Em slowed (7.51±3.78vs.10.54±3.89) cm/s,(P<0.05); Am slowed (5.83±2.34vs.6.86±2.88) cm/s,(P<0.05); Em/Am decreased (1.29±0.11vs.1.53±0.12),(P<0.05); E/Em increased (11.08±1.12vs14.20±0.87)(P<0.05); in the6th week, the experimental group’s E increased faster (118.6±6.9vs.89.5±7.2) (P<0.05); Em was significantly slower (6.23±1.43vs.9.64±2.36) cm/s,(P<0.01); Am slow (5.25±2.13vs.6.23±2.02) cm/s,(P<0.05); Em/Am was significantly reduced Small (1.18±0.14vs.1.54±0.24),(P<0.01); E/Em was significantly increased (15.06±2.10vs10.84±1.20)(P<0.01). The detection of left ventricular systolic function indexes declined at the6th week. Specifically speaking, in the6th week, compared with the control group, the experimental group’s LVEF decreased (88.65±8.02vs.93.98±6.92)%,(P<0.05); FS decreased (57.23±5.02vs.61.35±6.31)%,(P<0.05); Sm lower (7.45±2.87vs.8.46±2.98) cm/s,(P<0.05). The echocardiography which represented the diastolic function and hemodynamic indexes correlated well. E and LVEDP was positively correlated (r=0.873, P<0.000), Em was a negative correlation with LVEDP (r=-0.676, P<0.001), E/Em was positively correlated with LVEDP (r=0.703, P<0.001), E and-dp/dtmax negative correlation (r=-0.690, P<0.001), Em and-dp/dtmax was positively correlated (r=0.762, P <0.001), E/Em and-dp/dtmax negative correlation (r=-0.839, P<0.000). There was a positive correlation between the LVmass and the actual measured LVM (r=0.923, P <0.000).The Serum NT-proBNP levels in the2nd and4th week increased significantly and elevated in the6th week; NT-pro BNP was positively correlated with LVEDP (r=0.590, P<0.000); NT-pro BNP was negatively correlated with-dp/dtmax (r=-0.601, P<0.000).Results:The correlation between the Echocardiography and hemodynamic was good, so it could be an accurate assessment of left ventricular diastolic function; through analyzing echocardiography, the left ventricular filling could be determined in the different states; the correlation between the serum NT-pro BNP levels and left ventricular diastolic function decreased degree could be used for assessing the degree of ventricular diastolic function.Part three. The research of diastolic dysfunction during perioperative of thoracic surgeryObjective:Combined echocardiography and6-minute walking test (6MWT), to evauate left ventricular diastolic function of thoracic surgery patients; Discuss the different effect in patients of thoracic surgery on different degree of left ventricular diastolic dysfunction; Discuss the relationship between postoperative complications with degrees of left ventricular diastolic dysfunction in thoracic surgery patients; Preliminary discuss the correlation between serum NT-proBNP levels and left ventricular diastolic dysfunction degree, the change during perioperative impact threshold value of the diagnosis.Methods:From March2010to March2011, the patients in the our department who would be done thoracic surgery operation, with one or more risk factors for diastolic dysfunction, be evaluated by ultrasound to screened which with left ventricular diastolic dysfunction. On selected cases(165), the researchers grouped them according to echocardiography:group A75cases (impaired relaxation of the filling abnormalities,E/A<1), grade B58cases (pseudo-normalization,1≤E/A<1.5and E/Em>15or Em<7cm/s), group C32cases (restrictive filling abnormalities, E/A≥2, or1.5≤E/A<2and E/Em>15or Em<7cm/s).(Those risk factors included:①age≥60;②patients with hypertension;③diabetes;④hyperlipidemia,⑤combined with mild pulmonary dysfunction;⑥has Ⅰ, Ⅱ grade (NYHA) heart failure symptoms. If the following conditions appeared, the case would be excluded:①Ⅲ, Ⅳ-level cardiac function;②combined in ischemic cardiomyopathy patients with unstable angina in January near or myocardial infarction;③myasthenia gravis, cerebrovascular disease, Lower extremity vascular and motor system diseases;④arrhythmia;⑦serious insufficiency of liver and kidney function.). Patients in each group had6-minute walking test (6MWT) in one week before surgery and the researchers analyzed the differences among the groups in6-minute walk distance (6MWD) and got the diastolic function indices and some correlation. Giving the ultrasound before and immediately after the exercise, the researchers compared the cardiac function differences before and after the test and tested the amplitude index (△1) classification by pair wise differences between groups. In the3rd and8th day after the operation, the researchers went the ultrasound respectively and made the difference analysis between these results and the results of preoperative ultrasonography, then tested the difference between the indicators before and after the change range (△2). Madding the correlation analysis of△1and△2. The ultrasound parameters included:mitral valve blood Early diastolic peak flow velocity (E), atrial systolic mitral valve blood flow peak velocity (A), E/A value, peak early diastolic mitral annulus velocity (Em) peak late diastolic mitral annulus velocity (Am), peak systolic velocity of mitral annular Sm and E/Em, left ventricular ejection fraction (LVEF),the left ventricular wall thickness (LVWD,=LVPWD+IVSD), left ventricular end diastolic diameter before and after (LVEDD), left atrial end-systolic diameter before and after (LADs). Going on the ultrasound examination to the patients in each group on the same day in the morning, taking fasting blood2ml and the supernatant after centrifugation at room temperature, setting to-80℃refrigerator storage. The researchers tested the serum levels of NT-pro BNP with the uniform application in the study endpoint by the ELISA and made the correlation analysis, then compared all patients’ serum NT-proNP level differences with the3rd day and the8th day after the surgery; postoperative continuous monitoring of patient vital signs; monitor the arterial oxygen tension (Pa02), arterial lactate concentration and urine volume, record the time and postoperative care the amount of furosemide, compared the differences between the groups at all levels. Then the researchers calculated heart failure (HF), respiratory failure, kidney failure, the incidence of arrhythmia in each group after the surgery and made the comparative analysis for all levels between the groups. Statistical Package for all data handled by SPSS13.0. Measurement data as mean±standard deviation, using t test; statistics to P<0.05as significantly different, P<0.01as significant statistical difference.Results:After6MWT, ultrasound examination showed left ventricular diastolic function decreased in group B, significantly decreased in group C:E are faster,(P<0.05); E/A increased in group C (1.91±0.22vsl.72±0.21)(P<0.05); Em faster in group A (5.16±1.74vs.4.23±1.79)(P<0.05); E/Em values in group B (19.29±2.34vs.17.31±2.17)(P<0.05) and group C (25.34±2.37vs.23.23±3.01)(P<0.01) were increased; LVEF and Sm in all groups were significantly higher (P<0.05);△1Em there are differences in various groups (0.93±0.23vs0.41±0.12vs.0.14±0.04)(P<0.05),△1iE/Em there are differences in various groups (0.53±0.22vs.1.98±0.29vs.2.11±0.27)(P<0.05); Ultrasound examination showed that after3days compared with preoperative left ventricular diastolic function were decreased, systolic function in group B group and C decreased:E in all groups were faster (P<0.05); E/A in group B and C were higher (P<0.05); Em in group B and group C were lower (P<0.05); E/Em were significantly increased in all groups (P<0.05); LVEF decline in group C(56.6±13.4vs.62.2±10.3)(P<0.05); Sm in group B (6.05±1.77vs.7.15±1.43)(P<0.05) and group C (5.47±1.3vs.26.92±1.02)(P<0.05) are declining;△2LVEF,△2E/A,△2E/Em were differences among the groups (P<0.05).△1E/Em and△2E/Em the best correlation (r=0.893, P<0.000);△1E/A and△2E/A positive correlation (r=0.731, P<0.001);△1Em and△2Em was positively correlated (r=0.785, P<0.001); Serum NT-pro BNP levels and preoperative E/Em was a positive correlation, the best correlation (r=0.782, P<0.000); Serum NT-pro BNP preoperative differences between groups, with the rise of higher grade (79.32±25.43vs.89.54±18.16vs.96.35±16.22)(P<0.05). Heart failure incidence of grade group C more than group A (28.4%vs.13.3%)(P<0.05) and group B (28.2%vs.15.5%); the incidence of respiratory failure group C more than group A (21.9%vs.13.3%)(P<0.01) and group B (21.9%vs.13.8%)(P<0.01); arrhythmias group B more than group A (24.1%vs.17.3)(P<0.05), group C more than group A (21.8%vs.17.3)(P<0.01).Conclusion:The patients with left ventricular diastolic heart failure after the surgery were further aggravated in the left ventricular diastolic dysfunction, and it increased level of preoperative functional class was significantly improved and more;6MWT joint Doppler ultrasound could predict the increscent of the degree of diastolic dysfunction after surgery, and played the role of high-risk patients can be expected to further risk of heart failure; the elevated levels of serum NT-proBNP with left ventricular diastolic dysfunction grade increased, and the monitoring of serum NT-pro BNP could contributed to the diagnostic classification of diastolic function; the Serum NT-pro BNP levels increased preoperative, and the functional class improved, when give the diagnosis of CHF, the diagnostic threshold should be improved; patients with diastolic dysfunction in the chest surgery period got a high risk of heart failure and respiratory failure. |
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