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Objective To investigate the relationships between the structure ,function of left atrial as well as cardiac biomarkers and left atrial spontaneous echo contrast ( SEC ) in patients with non‐valvular atrial fibrillation ( NVAF ) ,and evaluate its predictive value for left atrial SEC . Methods T hirty‐four control subjects and 80 patients with NVAF were included ,patients with NVAF were divided into positive group ( 30 cases) and negative group ( 50 cases) according to w hether SEC was presented on transesophageal echocardiography ( T EE ) . Clinical and laboratory data were collected ,including medical history ,cardiac troponin I ( cT nI) ,and pro‐brain natriuretic peptide ( pro‐BNP ) ,etc . T hen CHA2 DS2‐VASc scores were calculated .The left atrial appendage width ( W LAA ) ,left atrial appendage depth ( DLAA ) ,left atrial appendage blood flow velocity ( V LAA ) ,left atrial volume index ( LAVI) and other parameters were measured by T EE and transthoracic echocardiography ( T T E) ,and left atrial ejection fraction ( LAEF ) was calculated . T he clinical and T EE parameters were compared between the positive and negative group ,T T E parameters and cardiac biomarkers levels were compared among the three groups ,and ROC curve was used to evaluate the diagnostic efficiency . Results ①Compared with those in control group ,the value of LAVI and pro‐BNP were significantly increased and LAEF was significantly decreased in negative group ( all P ＜ 0 .01 ) . ②Compared with those in negative group ,CHA 2 DS2‐VASc scores ,WLAA ,DLAA ,LAVI and pro‐BNP levels in positive group showed a significant increase ( all P ＜0 .01) ,LAEF and VLAA showed a significant reduction ( all P ＜0 .01) . ③cT nI between negative group and control group did not show statisticant difference ( P＞0 .05) ,but presented a significant increase in positive group compared with those in control group and negative group (all P ＜0 .01).T he AUC ,sensitivity and specificity of CHA 2 DS2‐VASc scores for SEC were 0 .71 (95% CI :0 .60 ～ 0 .82 ) ,73 .3% and 62 .0%,respectively .When left atrial structural and functional parameters (LAVI and LAEF ) combined with cardiac biomarkers (cT nI and pro‐BNP ) ,the AUC , sensitivity and specificity for SEC were 0 .90 (95% CI :0 .84 ～ 0 .97 ) ,74 .0% and 100%,respectively ,both enhanced w hen compared with CHA 2 DS2‐VASc scores alone ( P ＜ 0 .01 ).Conclusions Left atrial enlargement ,decreased function and elevated levels of cardiac biomarkers are associated with left atrial SEC in patients with NVAF .CHA2 DS2‐VASc scores can be used for perdicting left atrial SEC ,left atrial structural and functional parameters (LAVI and LAEF) combined with cardiac biomarkers (cT nI and pro‐BNP) provide significant increments in prediction of left atrial SEC .
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Objective To study the iodine nutritional status of pregnant women in Foshan City,Guangdong Province,and to provide basis for iodine supplementation scientifically for them.Methods In 2017,five districts Chancheng,Nanhai,Shunde,Sanshui and Gaoming in Foshan were selected.Each monitoring site was divided into five sections according to stratified random sampling in five directions:east,west,south,north and middle.One township (street) was taken in each section,and 20 pregnant women were taken from each township (street) to detected their family salt iodine and urinary iodine levels.Results A total of 500 edible salt samples were collected from the families of pregnant women,the median of salt iodine was 24.8 mg/kg,the qualified iodized salt consumption rate was 95.8％ (479/500),and the iodized salt coverage rate was 99.0％ (495/500).There was a statistically significant difference in the iodine content of edible salt of pregnant women in diffierent districts (H =26.9,P ＜ 0.05).A total of 500 urine samples were collected from pregnant women,the median of urinary iodine was 138.9 μg/L.There was a statistically significant difference in the levels of urinary iodine content of pregnant women in different districts (H =14.5,P ＜ 0.05).There was no statistically significant difference in urinary iodine of pregnant women during different stages of pregnancy (H =2.6,P ＞ 0.05).Conclusions The iodine intake for pregnant women is in a state of deficiency (＜ 150 μg/L) in Foshan of Guangdong Province.It is necessary to further strengthen the health education of key populations,and improve the iodine nutritional status of pregnant women.
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Objective:To explore the effect of endothelin-1 on atrial ifbrosis in patients with atrial ifbrillation (AF). Methods: A total of 72 patients with thoracotomy were studied, the patients were divided into 2 groups:AF group, n=39 and Sinus rhythm (SR) group, n=33. The mRNA and protein expressions of endothelin-1 (ET-1), platelet derived growth factor-B (PDGF-B) and collagen I (COL1) in right atrial appendage (RAA) tissue were measured by RT-PCR and Western blot analysis;meanwhile, the impact of ET-1 stimulation and non-selective ET-1 receptor antagonist (sulfafurazole SIZ) on PDGF-B mRNA and protein expressions in H9c2 cells were measured. Results: ①The RAA tissue mRNA and protein expressions in AF group were higher than those in SR group, as for ET-1 (2.830 ± 2.276) vs (1.220 ± 0.887) and (0.835 ± 0.241) vs (0.286 ± 0.083), both P Conclusion: ET-1 plays an important role in AF occurrence which might be related to PDGF-B regulation.
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Objective To investigate the effect of microRNA-101 (miRNA-101) on atrial fibrosis in human chronic atrial fibrillation (AF). Methods Right atrial appendages were obtained from 59 patients (30 with AF) undergoing cardiac surgery, including 47 patients with valve heart disease and 12 patients with congenital heart disease. The expression of miRNA-101 was determined by quantitative real-time PCR in the right atrial appendages of patients with and without AF. The cell-specific localization of miRNA-101 was detected by in situ hybridization assay. The mRNA and protein expression levels of transforming growth factor β typeⅠreceptor (TGFβRⅠ) and collagen type I (COL1) were determined by quantitative real-time PCR and Western-blot assay, respectively. Collagen in the right atrial appendages was observed by Masson staining assay. Results The expression of miRNA-101 was found to be significantly down-regulated in AF patients compared with patients with sinus rhythm (SR) (P 0.05). But the protein expression of TGFβRI in patients with AF was significantly higher than that of patients with SR (P < 0.05). The mRNA and protein expressionsl of COL1 were significantly higher in patients with AF than thoset of patients with SR (P < 0.05). The collagen was significantly increased in patients with AF than that of patients with SR (P < 0.05). Conclusions Downregulation of miRNA-101 may contribute to atrial fibrosis in human atrial fibrillation by targeting TGFβRⅠ.
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Objective To study the correlation between the cytochrome P450 3A5 gene polymorphism and essential hypertension (EH) in Chinese population .Methods The real-time PCR genotyping at CYP3A5*3(6986A>G) position was established using Taqman minor groove binding (MGB) probes .Total 170 EH patients and 193 matched controls of Chinese Han population were genotyped at CYP3A5*3(6986A>G) position using this method .Results The GG ,GA ,AA genotyped frequencies were 51 .2% , 42 .4% and 6 .5% for the EH patients and 39 .9% ,50 .8% and 9 .3% for the control group respectively .The risk of EH for person carrying GG genotype was 1 .579 fold of the persons carrying at least one A allele(95% CI:1 .041-2 .395) .Conclusion CYP3A5*3(6986A>G) polymorphism may be associated with EH in Chinese population .The risk of EH is decreased in the persons carrying allele A ,slightly lower levels of systolic blood pressure exists .
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AIM: To investigate the effects of heptanol preconditioning on the changes of structure, function and connexin 43 (Cx43) content in mitochondria in a rabbit model of myocardial isehemia-reperfusion (IR) injury. METHODS: In anesthetized open-chest rabbits, the left anterior descending artery (LAD) was occluded for 30 min and reperfused for 4 h. Sixty-four rabbits were randomly divided into 4 groups (n=16 in each group): sham operation group (sham group), ischemia-reperfusion group (IR group), ischemic preconditioning group (IP group) and heptanol preconditioning group (HT group). All rabbits in the 4 groups were killed 4 h after reperfusion. Myocardial infarct size was determined at the end of the experiment. Mitochondria was isolated by centrifugations. The ultrastructural changes of the mitochondria were observed under electronic microscope. The mitochondrial membrane potential, Ca~(2+) concentration, MDA content and SOD activity of myocardial mitochondria were also examined. The content of mitochondria Cx43 was detected by Western blotting. RESULTS: Compared to IR group, the myocardial infarct size was significantly reduced in IP (18.97%±2.80%) and HT (19.97%±3.80%) groups, the damage of mitoehondrial ultrastructure was milder (P<0.05), mitochondrial membrane potential was significantly higher and Ca~(2+) concentration was much lower (P<0.01) in IP group and HT group. No significant difference of MDA content and SOD activity in myocardial mitochondria between IR group and HT group was found. However, MDA content were much lower and SOD activity was significantly higher in IP group as compared to IR group (P<0.01). Compared to sham group, the mitochondria Cx43 expression was distinctly decreased compared to IR group (P<0.05) and no significant difference was found between IP group and HT group (P>0.05). CONCLUSION: Heptanol preconditioning protects myocardium from ischemia-reperfusion injury. The mechanism may be related to increasing in mitochondrial membrane potential, alleviating Ca~(2+) overload in myocardial mitochondria and attenuating the decrease in mitochondria Cx43 expression induced by isehemia-reperfusion.
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Objective To investigate the alterations of connexin 43 (Cx43) expression and its distribution at different stages of myocardial infarction (MI) in rats after transplantation of allogenic mesenchymal stem cells (MSCs).Methods Wistar rats were ligated on the left anterior descending coronary artery to make MI models.They were injected with allogenic MSCs,which were induced by 5-aza and labelled by DAPI,during the second operation after 7 days of MI.In subgroups,MSCs were detected by fluorescence microscope.Cx43 expression and GJ distribu-tion were examined by immunohistochemistry after 4,8 or 12 weeks respectively.Results MSCs differentiated into cardiac muscle cell-like cells which were capable of pulsing spontaneously,expressing cTnT and forming myofilament in vitro.Transplanted MSCs can survive in MI host and upregulate Cx43 expression and normalize Cx43 distribution at ischemic zones after 4,8 and 12w.No change of Cx43 was seen at infarcted zones.Conclusion MSCs have the plasticity of differentiating into cardiac muscle cell-like cells which can continuously upregulate Cx43 expression and normalize Cx43 distribution at ischemic zones after 4,8 and 12w.
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Objective To investigate the effects of ischemic postconditioning on apoptosis, structural and functional changes of mitochondria induced by myocardial isehemia/reperfusion (I/R) injury of rabbits and potential mechanism. Methods Eighty healthy rabbits were divided randomly into five groups: sham operation group ( Group Sham) , ischemic reperfusion group (Group IR) , ischemic preconditioning group (Group IP) , ischemic postconditioning group (Group PC) and 5-HD plus ischemic postconditioning group (Group PC +5-HD). All rabbits in the five groups were killed 4 h after reperfusion. The hearts were quickly collected for microscopy by TUNEL. We observed ultrastructural changes of myocardium under electron microscope and examined mitochondrial membrane potential and Ca~(2+) concentration, MDA content and SOD activity of myocardial mitochondria. Results Compared with group IR, the damage of mitoehondrial ultrastrueture was milder, the apoptosis rate decreased and Ca concentration and MDA content were much lower in group IP and group PC ( P < 0. 05 ). Mitochondrial membrane potential and SOD activity of myocardial mitochondria in group IP and group PC was significantly higher than that in group IR(P<0.05). The protective effect of PC against I/R injury was partially counteracted by 5-HD .Conclusion Ischemic posteonditioning can protect the heart from I/R injury, this is supported by improvement mitochondrial ultrastructure and by decreasing apoptosis, increasing mitochondrial membrane potential and SOD activity, alleviating Ca~(2+) overload and decreasing MDA content in myocardial mitochondria. The cardio protective effects may be explained by mitochondrial ATP sensitive potassium channel.
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Objective To investigate the relationship between cardiac vagus nerves and changes of connexins(Cx)and intracellular gap junction(GJ)distribution pattern in superior vena cava(SVC)myosleeve in dog with atrial fibrillation(AF).Methods Twenty four hybrid dogs were divided into sham operation group(Sham group,n=8),SVC-AO fat pad removed group(RM group,n=8)and SVC-AO fat pad reserved group(RS group,n=8).In RM group and RS group,right atrial pacing was performed at a frequency of 500～650/min for 6 weeks to establish AF model.AF was induced by programmed stimulation or burst stimulation of atrial pacing.The expression and distribution of Cx40 and Cx43 in the SVC myosleeve tissue in three groups were analyzed by immunofluorescence staining.Transmission electron microscopy was used to observe the uhrastructural organization of gap junction(GJ).Results The rate of inducing sustained AF(＞ 15 min)in RS group was significantly higher than that in RM group (P ＜ 0.01).The expression of Cx40 and Cx43 in the SVC myosleeve in sham group and RS group were significantly higher than that in RM group(P ＜ 0.05).Furthermore,the expression of Cx40 and Cx43 in RS group were obviously higher than that in sham group(P ＜0.05).The ratio of end-to-end to side-to-side in RS group was lower than that in Sham group and RM group.Comparing with RM group,the channel of GJ became shorter and wider in RS group(P ＜0.05).Sarcomere was dissolved and mitochondrion showed vacuole degeneration in RS group.Conclusion The remodeling of Cx40 and Gx43 in SVC myosleeve tissue may be mediated by vagus nerves.It is conducive to the maintenance and stability of AF.However,this effect can be weakened by removing SVC-AO fat pad of canine.
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BACKGROUND: Stem cell transplantation in repairing infarct myocardium and in improving cardiac function has been widely accepted. However, whether transplanted cells and host cells formed an effective electricity and mechanical couple, whether a relevant independent electrical system with contractile function formed or whether severe malignant ventricular arrhythmia formed, are still unclear.OBJECTIVE: To investigate electrophysiological abnormaltiy and left ventricular remodeling in rats with myocardial infarction following allogenic bone marrow mesenchymal stem cell (BMSC) transplantation.DESIGN, TIME AND SETTING: The randomized controlled animal study was performed at the Experimental Center, Guangxi Medical University from December 2005 to October 2008.MATERIALS: A total of 120 healthy Wistar rats were equally randomized into normal control, sham operation, saline control and cell transplantation groups. Healthy Wister rats aged 1 month were selected to harvest bone marrow.METHODS: At the third passage, rat BMSCs were collected and treated with 5-aza, and differentiated into cerdiomyocytes.BMSCs were labeled with DAPI at 2 hours before transplantation. In the saline control and cell transplantation groups, rat models of myocardial infarction were established by ligating the left anterior descending coronary artery. In the sham operation group, the coronary artery was not ligated, but only braid. At 7 days following ligation, BMSCs in the cell transplantation group at 2×10-1/L were infused into the edge and center of myocardial infarct region by multipoint injection. Rats in the other three groups were subjected to an equal volume of saline.MAIN OUTCOME MEASURES: Electrocardiogram and cardiac electrophysiology were performed. Ultrasonic cardiography was used to detect left ventricular function. Infarct size was determined. DAPl-labeled donor cell migration and distribution was observed with a fluorescence microscope.RESULTS: BMSCs could differentiate into cardiacmuscle cell-like cells which were capable of pulsing spontaneously, expressing cardiactoponin T and forming myofilament in vitro. Compared with the saline control group, PR interval, QRS duration and ventdcular effective refractory period shortened, ventricular fibrillation threshold increased at 4, 8 and 12 weeks (P < 0.05); left ventricular internal diameter at end-systole reduced, and left ventricular ejection fraction and shortening traction was significantly increased (P< 0.05). At 8 and 12 weeks, infarct size was significantly smaller (P < 0.05). At 4 weeks, DAPl-labeled BMSCs could be seen under the fluorescence microscope, and still could he detected at 12 weeks. However, the fluorescence became weak with prolonged time.CONCLUSION: BMSCs have the plasticity of differentiating into cardiac muscle cell-like cells, which can modulate theelectrophysiological abnormality and left ventricular remodeling following myocardial infarction.
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BACKGROUND:Cell transplantation can repair damaged myocardial tissue.However,whether transplaned cells and host cells formed an effective electricity and mechanical couple or whether reconstruction of connexin (Cx) and arrhythmia formed,are still unclear.OBJECTIVE:It is hypothesized that arrhythmia can be treated by changing Cx levels and intervening abnormal GJ channel.Moreover,to explore the effects of bone marrow mesenchyma stem cells (MSCs) on the expression of Cx43 and Cx45 in rata with myocardial infarction.DESIGN,TIME AND SETTING:The randomized controlled animal study was performed at the Experimental Center,Guangxi Medical University from January 2008 to May 2009.MATERIALS:A total of 180 Wistar rats were randomly divided into four groups:normal control,sham operation,myocardial infarction,and MSCs,with 45 animals in each group.Each group was then divided into 3 subgroups (n=15) according to 4 weeks,8 weeks and 12 weeks post-transplantation.Additional 20 healthy,Wistar rats,aged 1 month,were selected to harvest MSCs.METHODS:The third passage of MSCs was induced by 5-aza like cardiomyocytes for 4 weeks,labeled with DAPI at 2 hours before transplantation.Models of acute myocardial infarction were established in all groups except sham operation group.At day 7 after model preparation,2×10~(10) /L MSCs were infused into the edge and center of myocardial infarcted region by multipoint injection.Rats in the myocardial infarction group were subjected to an equal volume of saline as wall as those in the normal control and sham operation groups.MAIN OUTCOME MEASURES:The mRNA expressions of Cx43,Cx45 were assayed by fluorescence quantitative PCR.RESULTS:The mRNA expression of Cx43 among each groups had no difference at weeks 4,8 and 12 after intervention in the normal areas.Compared to the normal areas,Cx43 mRNA reduced significantly at ischamic zone in the myocardial infarction group and MSCs group (P＜0.01),with notably increased of Cx45 mRNA expression (P＜0.01).Compared to myocardial infarction group,Cx43 mRNA expression was statistically higher in the MSCs group at the same points (P ＜ 0.01),and the Cx45 mRNA dramatically declined (P ＜ 0.01).CONCLUSION:Acute myocardial infarction reduces the mRNA expression of Cx43 and increases the Cx45 mRNA expression.The exogenous cells transplantation can upturn the mRNA expression of Cx43 in the border-zone of the infarcted area,and down-regulate the Cx45 mRNA expression in the border-zone of the infarcted area.
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Aim To investigate the roles of Cx43 in mitochondria and mitochondrial ATP sensitive potassium channe1(mitoK_(ATP)~+)participating in the protection for heptanol preconditioning on myocardial ischemia/reperfusion injury of rabbits.Methods In anesthetized open-chest rabbits,the left anterior descending artery(LAD)was occluded for 30 min and reperfused for 4 hrs.All rabbits were randomly divided into five groups(n=16 in each group):sham operation group(Group Sham),ischemic reperfusion group(Group IR),ischemic preconditioning group(Group IP),heptanol preconditioning group(Group HT)and 5-HD plus heptanol preconditioning group(Group HT+5-HD),All rabbits in the five groups were killed 4h after reperfusion.Myocardial infarct size was determined at the end of the experiment.The heart rate and the mean arterial pressure(MAP)were recorded and plasma CK-MB and cTnI activity were measured at baseline,the end of ischemia,and after 2 hrs and 4 hrs of reperfusion respectively.Mitochondria was isolated with different centrifugations.Ultrastructural changes of mitochondria were observed under electron microscope.The content of the mitochondria Cx43 was detected with Western blot.Results The plasma CK-MB,cTnI activity and myocardial infarct size were significantly reduced in IP(18.97±2.8)% and HT(19.97±3.8)% groups as compared to IR groups (35.67±5.8)%,(P<0.01).Compared to group IR,the damage of mitochondria in group IP and group HT were milder(P<0.01).No significant difference was found between Group IP and Group HT.Compared to sham group, the mitochondria Cx43 expression was distinctly decreased in group IR and group HT+5-HD(P<0.01)and no significant difference was found between Group IP and Group HT.Conclusions Heptanol preconditioning can protect the heart from I/R injury by improving mitochondrial ultrastructure and by attenuating the decrease of mitochondria Cx43 expression induced by I/R.The mitochondrial Cx43 expression may be concerned with depending on mito K_(ATP)~+.
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Objective To establish a stable,repeatable and long-lasting rat model of myocardial infarction,and to evaluate the feasibility of monitoring electrophysiological changes and left ventricular function after myocardial infarction by electrocardiography (ECG) and ultrasonic cardiography(UCG). Methods Wistar rats were ligated on the left anterior descending coronary artery after anaesthesia with 10% chloral hydrate and machinery assisted respiration. Then they were monitored by ECG and UCG afer 4,8 and 12 weeks,and were sacrificed and pathologically examined at 12 weeks after operation. Results The rat model of myocardial infarction was established with a survival rate of 83.3% at 72 hours after the operation and 73.3% at 12 weeks after the operation. In the myocardial infarction group,the PR,QRS,QT and QTc intervals were statistically significantly longer than that in the sham operation group. UCG showed that the left ventricular internal diameter at end-diastole (LVIDd) and the left ventricular internal diameter at end-systole (LVIDs) were statiscally significantly higher in the infarction group,and the ejection fraction (EF) and fractional shortening (FS) significantly lower than those in the sham operation group. Long-lasting pathological changes can be seen in the tissues at 12 weeks after operation. Conclusions The method used in the present study is an simple,less injurious and highly successful technique,and the changes in electrophysiology and left ventricular function can be well monitored by ECG and UCG at different times during this period.
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Objective To study the effect of Tongxinluo on the plasma C-reactive protein(CRP)and endothelin-1(ET-1)in acute coronary syndrome(ACS) patients.Methods 100 patients with ACS were randomly divided into conventional therapy group and treatment group(conventional therapy+Tongxinluo gelatin capsule).The changes of CRP and ET-1 in the first day,7th and 14th day were observed.Results In the treatment group,CRP and ET-1 were significantly decreased in the 7th and 14th day(P＜0.05,P＜0.01),and there was significant decrease only in the 14th day(P＜0.05)in the conventional therapy group.CRP and ET-1 levels in the treatment group were significantly different as compared with conventional thereapy group(P＜0.01).Conclusion Tongxinluo capsule may protect blood vessel endothelium through inhibiting CRP and ET-1 to decrease the inflammatory response of endangium.
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Gap junctions(GJ) form the chemical signal channels between cardiocytes.The core proteins of these channels are the connexins(Cx).The quantity or distribution of Cx will lead to the remodeling of GJ, which contributed to arrhythmia and remodeling following the acute myocardial infarction.GJ remodeling is the key reason and pathological basis of arrhythmia following acute myocardial infarction.How to increase the number of myocardial cells and lighten or reverse the heart reconstitution have become a focal point.In the acute myocardial infarction cell transplantation treatment, stem cells are characterized by self-renewal and multi-directional differentiation have been paid great attention.This study summarized the basis and clinical research of GJ structure, function, distribution, remodeling and stem cell transplantation treatment following myocardial infarction.
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Objective To develop rats model for human dilated cardiomyopathy(DCM).Methods Male Sprague-Dawley rats were administered adriamycin intraperitoneally 2.8 mg/kg? week)for 11 weeks,and then observed for 2 weeks.Plasma levels of brain natriuretic peptide(BNP)were studied by ELISA;left ventricular end diastolic diameter(LVEDD),left ventricular end systolic diameter(LVESD)and left ventricular ejection fraction(LVEF)were measured by echocardiogram;and morphology of the hearts and pathological lesions of cardiac muscle tissues were observed.Results(1)The levels of BNP of the DCM group were higher than those of the normal group(P