NONLINEAR DYNAMICS MODFLING OF MECHANICAL PERIODICITY OF END DIASTOLIC VOLUME OF LEFT VENTRICLE

The cardiovascular system with a lumped parameter model is treated, in which the Starling model is used to simulate left ventricle and the four-element Burattini & Gnudi model is used in the description of arterial system. Moreover, the feedback action of arterial pressure on cardiac cycle is taken into account. The phenomenon of mechanical periodicity (MP) of end diastolic volume (EDV) of left ventricle is successfully simulated by solving a series of one-dimensional discrete nonlinear dynamical equations. The effects of cardiovascular parameters on MP is also discussed.

Effect of rheumatic mitral stenosis on end-diastolic volume of left ventricle

Objective To investigate the relations between the pathological contraction of the valve and sub-valvular apparatus in rheumatic mitral stenosis and end-diastolic volume of left ventricle. Method From 1990-2004, 90 patients with only moderate or severe rheumatic mitral stenosis （mitral group）, and 24 patients with combined moderate or severe rheumatic mitral stenosis and significant aortic regurgitation （ combined valves group）, diagnostically confirmed by surgery and pathology, were measured using echocardiaogram the end-diastolic volume and diameter, stroke volume and ejection fraction of left ventricle. Result Compared with mitral group combined valves group showed slight increases of end-diastolic volume and diameter （116.49 ± 37.93 ml and 136.72±70.67 ml, respectively; 49.34 ± 6.71 mm and 51.08 ± 8.32 mm, respectively; both P 〈 0.05）, and slight decreases of ejection fraction, but significant increases of stroke volume （71.37 ± 25.01 ml and 91.06 ± 36.67 ml, respectively; P〈0.05） of left ventricle. Conclusion The pathological shortening of mitral valve and sub-valvular apparatus caused by long-term rheumatic disease is the main cause of decreased left ventricular volume in mitral stenosis.

Double-chambered left ventricle with a thrombus in an asymptomatic patient:A case report

BACKGROUND Double-chambered left ventricle(DCLV)is an extremely rare congenital disease in which the left ventricle(LV)is divided by abnormal muscle tissue.Due to its rarity,there is a lack of data on the disease,including its diagnosis,treatment,and prognosis.Accordingly,we report a case in which DCLV was diagnosed and followed up.CASE SUMMARY A 45-year-old man presented to our hospital due to abnormal findings on an electrocardiogram recorded during a health check.He had no specific cardiac symptoms,comorbidities or relevant past medical history.Echocardiography revealed that the LV was divided into two by muscle fibers.There were no findings of ischemia on coronary angiography and coronary computed tomography angiography performed to exclude differential diagnoses.After comprehensive analysis of the images,DCLV was diagnosed.As it seemed to be asymptomatic DCLV,we decided the patient was to be observed without administering any medication.However,follow-up echocardiography revealed a thrombus in the accessory chamber(AC).Anticoagulant medication was initiated,the thrombus resolved,and the patient is currently undergoing follow-up without any specific symptoms.CONCLUSION Asymptomatic,uncomplicated DCLV was diagnosed through multimodal imaging;however,a thrombus in the AC occurred during the follow-up.The findings highlight that multimodal imaging is essential in diagnosing DCLV,and that anticoagulation is important in its management.

An Interpretable CNN for the Segmentation of the Left Ventricle in Cardiac MRI by Real-Time Visualization

The interpretability of deep learning models has emerged as a compelling area in artificial intelligence research.The safety criteria for medical imaging are highly stringent,and models are required for an explanation.However,existing convolutional neural network solutions for left ventricular segmentation are viewed in terms of inputs and outputs.Thus,the interpretability of CNNs has come into the spotlight.Since medical imaging data are limited,many methods to fine-tune medical imaging models that are popular in transfer models have been built using massive public Image Net datasets by the transfer learning method.Unfortunately,this generates many unreliable parameters and makes it difficult to generate plausible explanations from these models.In this study,we trained from scratch rather than relying on transfer learning,creating a novel interpretable approach for autonomously segmenting the left ventricle with a cardiac MRI.Our enhanced GPU training system implemented interpretable global average pooling for graphics using deep learning.The deep learning tasks were simplified.Simplification included data management,neural network architecture,and training.Our system monitored and analyzed the gradient changes of different layers with dynamic visualizations in real-time and selected the optimal deployment model.Our results demonstrated that the proposed method was feasible and efficient:the Dice coefficient reached 94.48%,and the accuracy reached 99.7%.It was found that no current transfer learning models could perform comparably to the ImageNet transfer learning architectures.This model is lightweight and more convenient to deploy on mobile devices than transfer learning models.

Value of clinical applications of differential pressure and relative pressure imaging in the left ventricle

Regional pressure differences between sites within the left ventricular cavity have long been identified,and the potential clinical value of diastolic and systolic intraventricular pressure differences(IVPDs)is of increasing interest.This study concluded that the IVPD plays an important role in ventricular filling and emptying and is a reliable indicator of ventricular relaxation,elastic recoil,diastolic pumping,and effective left ventricular filling.Relative pressure imaging,as a novel and potentially clinically applicable measure of left IVPDs,enables early and more comprehensive identification of the temporal and spatial characteristics of IVPD.In the future,as research related to relative pressure imaging continues,this measurement method has the possibility to become more refined and serve as an additional clinical aid that can replace the gold standard cardiac catheterization technique for the diagnosis of diastolic dysfunction.

Inadvertent Lead Malposition in the Left Ventricle during Permanent Ventricular Pacing about One Case

Inadvertent Lead Malposition in Left Ventricle is a rare and underdiagnosed incident, which may occur during implantation of cardiac electronic devices and may remain asymptomatic. We reported the case of a 71-year-old man who was implanted with a ventricular single-chamber pacemaker for a slow atrial fibrillation with syncope and whose routine transthoracic echocardiography 23 months after implantation displayed a malposition of the pacemaker lead into the Left Ventricle through a patent foramen oval. The patient was asymptomatic. The electrocardiogram showed right bundle branch block QRS-paced morphology with a positive QRS pattern in V1, a median paced QRS axis on the frontal plane at -120°, a Precordial transition on V5. At the lateral Chest X-ray the lead curved backwards to the spine. Given the age of this old patient who already received oral anticoagulant for Atrial Fibrillation and the Lead malposition discovered 23 months after pacemaker’s implantation, we decided to maintain the lead in LV and continue anticoagulation.

Three-dimensional echocardiographic assessment of left ventricular volume in different heart diseases using a fully automated quantification software

BACKGROUND HeartModel(HM)is a fully automated adaptive quantification software that can quickly quantify left heart volume and left ventricular function.This study used HM to quantify the left ventricular end-diastolic(LVEDV)and end-systolic volumes(LVESV)of patients with dilated cardiomyopathy(DCM),coronary artery heart disease with segmental wall motion abnormality,and hypertrophic cardiomyopathy(HCM)to determine whether there were differences in the feasibility,accuracy,and repeatability of measuring the LVEDV,LVESV,LV ejection fraction(LVEF)and left atrial end-systolic volume(LAESV)and to compare these measurements with those obtained with traditional twodimensional(2D)and three-dimensional(3D)methods.AIM To evaluate the application value of HM in quantifying left heart chamber volume and LVEF in clinical patients.METHODS A total of 150 subjects who underwent 2D and 3D echocardiography were divided into 4 groups:(1)42 patients with normal heart shape and function(control group,Group A);(2)35 patients with DCM(Group B);(3)41 patients with LV remodeling after acute myocardial infarction(Group C);and(4)32 patients with HCM(Group D).The LVEDV,LVESV,LVEF and LAESV obtained by HM with(HM-RE)and without regional endocardial border editing(HM-NE)were compared with those measured by traditional 2D/3D echocardiographic methods to assess the correlation,consistency,and repeatability of all methods.RESULTS(1)The parameters measured by HM were significantly different among the groups(P<0.05 for all).Compared with Groups A,C,and D,Group B had higher LVEDV and LVESV(P<0.05 for all)and lower LVEF(P<0.05 for all);(2)HM-NE overestimated LVEDV,LVESV,and LAESV with wide biases and underestimated LVEF with a small bias;contour adjustment reduced the biases and limits of agreement(bias:LVEDV,28.17 mL,LVESV,14.92 mL,LAESV,8.18 mL,LVEF,-0.04%).The correlations between HM-RE and advanced cardiac 3D quantification(3DQA)(r_(s)=0.91-0.95,P<0.05 for all)were higher than those between HM-NE(r_(s)=0.85-0.93,P<0.05 for all)and the traditional 2D methods.The correlations between HM-RE and 3DQA were good for Groups A,B,and C but remained weak for Group D(LVEDV and LVESV,r_(s)=0.48-0.54,P<0.05 for all);and(3)The intraobserver and interobserver variability for the HM-RE measurements were low.CONCLUSION HM can be used to quantify the LV volume and LVEF in patients with common heart diseases and sufficient image quality.HM with contour editing is highly reproducible and accurate and may be recommended for clinical practice.

Assessment of Left Atrial Function in Diabetes Mellitus by Left Atrial Volume Tracking Method

The value of the left atrial volume tracking (LAVT) method in the evaluation of left atrial (LA) function in patients with diabetes mellitus (DM) was examined in this study.Fifty-eight DM patients as DM group and 40 healthy people as normal control group were enrolled in this study.EUB-6500 echocardiographic imaging system with LAVT was applied to display and analyze the LA volume curve imaging on LV apical two and four chamber views.The maximal LA volume at end-systole (LAV max),LA volume at the onset of ECG-P wave (LAV p),the minimal LA volume at end-diastole (LAV min) from the LA volume curve were acquired and recorded.All values above were standardized by body surface area (BSA).Then the passive,active and total LA volume (LAVIpass,LAVIact,LAVItotal) and empting rate (%LAVIpass,%LAVIact,%LAVItotal),effective passive and active empting rate (%eLAVIpass,%eLAVIact),and the proportionality of passive empting volume and active empting volume were calculated.The LAVIp,LAVIact,LAVItotal,%LAVIact,%LAVItotal and %eLAVIact were significantly higher in the DM group than those in the control group,whereas the LAVIpass,%LAVIpass,%eLAVIpass and LAVIpass/act were lower (all P【0.05).For the LA volume change in DM,the active empting volume was enhanced at end-diastole.It was concluded that LAVT is a potentially useful tool to evaluate the function of LA.

A NUMERICAL MODEL OF LEFT VENTRICLE AND AORTIC VALVE FUNCTION OF ITS AFTERLOAD(Ⅰ)

Due to the study of the function of heart and aoritic valve, we set up a physicalmodel of left ventricle, aortic valve and afterload and derive theoretical equation of each part from the model. Then we calculate the hasic equations within phystology and impair parameters. Bwsed on this, we will discus fully in the next paper the effectofleyt ventricular afterloadon valve opining, ejection and valve Jumction .etc

Left Atrial Volume Index in Patients with Dilated Cardiomyopathy—Correlation with Left Ventricular Function

Background: The aim of this study was to determine the relation of left atrial (LA) volume and LA volume index with left ventricular function and to determine the association of duration of symptoms and left atrial volume index in patients with dilated cardiomyopathy. Materials and Methods: This was an observational, single centre study conducted in India. A total of 50 patients who were admitted to department of cardiology from July, 2008 to February, 2009 with diagnosis of dilated cardiomyopathy and an ejection fraction of <40% were included. Results: Of the 50 patients, 34 (68%) were males. 27 (54%) patients were in NYHA class II and 23 (46%) patients were in NYHA class III. LA volume was found to be ≥40 ml in all patients. LV function and LA volume were found to be correlated (r = -0.789, p < 0.01). Similarly, there was a correlation between LV function and LA volume index (r = -0.826, p < 0.01). There was no correlation between LA volume index and duration of symptoms (r = 0.04). Conclusion: It can be concluded that there is a strong inverse correlation between LA volume and left ventricular function and also between LA volume index and left ventricular function. The patients with NYHA class III were having larger left atrial volume than those with NYHA class II. Moreover, the duration of symptoms has no correlation with left atrial volume index.

Preliminary Clinical Study of Real-time Three-dimensional Echo-cardiographic Volume-time Curve in Evaluating Left Ventricular Diastolic Function

The volume-time curve change in patients with normal left ventricular （LV） diastolic function and diastolic dysfunction was evaluated by real-time three-dimensional echocardiography （RT3DE）. LV diastolic dysfunction was defined by E＇〈A＇ in pulse-wave tissue Doppler for inter-ventricular septal （IVS） of mitral annulus. In 24 patients with LV diastolic dysfunction, including 12 patients with delayed relaxation （delayed relaxation group） and 12 patients with pseudo-normal function （pseudo-normal group） and 24 normal volunteers （control group）, data of full-volume image were acquired by real-time three-dimensional echocardiography and subjected to volume-time curve analysis. EDV （end-diastolic volume）, ESV （end-systolic volume）, LVEF （left ventricular ejection fraction）, PER （peak ejection rate）, PFR （peak filling rate） from RT3DE were examined in the three groups. Compared to the control group, PFR （diastolic filling index of RT3DE） was significantly reduced in the delayed relaxation group and pseudo-normal group （P〈0.05）. There were no significant differences in EDV, ESV, LVEE PER （P〉0.05）. It is concluded that PFR, as a diastolic filling index of RT3DE, can reflect the early diastolic function and serve as a new non-invasive, quick and accurate tool for clinical assessment of LV diastolic function.

Systematic Evaluation of Current Possibilities to Determine Left Ventricular Volumes by Echocardiography in Patients after Myocardial Infarction

Purpose: The aim of the present study was to evaluate the diagnostic accuracy for quantification of left ventricular (LV) volumes and LV ejection fraction (LVEF) with current echocardiographic methods of planimetry for analysis of LV remodeling after myocardial infarction in daily clinical routine. Methods: 26 patients were investigated directly after interventional therapy at hospital pre-discharge and at 6 month follow-up. Standardized 2D transthoracic native and contrast echocardiography were performed in all patients. Due to methodological aspects the results of LV volumes and LVEF using native echocardiography were compared to the results of LV opacification (LVO) imaging for analysis in mono-, bi- and triplane data sets using the Simpson’s rule. In addition corresponding multidimensional data sets were analyzed. Results: The assessment of LV volumes and LVEF is more accurate with contrast echocardiography. The comparison of LV volumes and LVEF shows significant increases using contrast echocardiography (p < 0.001). Larger left ventricular end-diastolic volumes (LVEDV) are measured at follow up (p < 0.05). Significant differences (p < 0.001) are found for the determination of LVEDV and LVEF relating to apical mono-, bi-, tri- and multiplane data sets. Standard deviations of the triplane approach, however, are significantly lower than using other modalities. Conclusion: Depending on the localization of the myocardial infarction LV volumes and LVEF are less reliably evaluated using the mono- or biplane approach. According to standardization and simultaneous acquisition of all LV wall segments the triplane approach is currently the best approach to determine LV systolic function. In addition, contrast echocardiography is indicated to improve endocardial border delineation in patients using the triplane or multiplane approach. To our knowledge the present study is the first systematic evaluation of all current possibilities for determination of LV volumes and LVEF by native and contrast echocardiography.

Liver cirrhosis and left ventricle diastolic dysfunction: Systematic review

BACKGROUND Liver cirrhosis is a chronic hepatic disease which is associated with cardiovascular abnormalities.Hyperdynamic circulation in liver cirrhosis causes functional and structural cardiac alterations.The prevalence of left ventricle diastolic dysfunction(LVDD)in cirrhotic patients ranges from 25.7%to as high as 81.4%as reported in different studies.In several studies the severity of diastolic dysfunction(DD)correlated with a degree of liver failure and the rate of dysfunction was higher in patients with decompensated cirrhosis compared with compensated.Future directions of comprehensive assessment of cardiac function in cirrhotic patients might provide a better prognosis for these patients.AIM To clarify the correlation between the severity of liver cirrhosis and left ventricle diastolic dysfunction in the existing literature.METHODS Through January and February of 2019 at Vilnius University we conducted a systematic review of the global existing literature on the prevalence of left ventricle diastolic dysfunction in patients with liver cirrhosis.We searched for articles in PubMed,Medline and Web of science databases.Articles were selected by using adequate inclusion and exclusion criteria.Our interest was the outcome of likely correlation between the severity of cirrhosis[evaluated by Child-Pugh classes,Model For End-Stage Liver Disease(MELD)scores]and left ventricle diastolic dysfunction[classified according to American Society of Echocardiography(ASE)guidelines(2009,2016)],as well as relative risk of dysfunction in cirrhotic patients.Subgroup analyses were performed to evaluate the ratio and grades of left ventricle diastolic dysfunction with respect to cirrhosis severity.RESULTS A total of 1149 articles and abstracts met the initial search criteria.Sixteen articles which met the predefined eligibility criteria were included in the final analysis.Overall,1067 patients(out of them 723 men)with liver cirrhosis were evaluated for left ventricle diastolic dysfunction.In our systemic analysis we have found that 51.2%of cirrhotic patients had left ventricle diastolic dysfunction diagnosed and the grade 1 was the most prevalent(59.2%,P<0.001)among them,the grade 3 had been rarely diagnosed-only 5.1%.The data about the prevalence of diastolic dysfunction in cirrhotic patients depending on Child-Pugh Classes was available from 5 studies(365 patients overall)and only in 1 research diastolic dysfunction was found being associated with severity of liver cirrhosis(P<0.005).We established that diastolic dysfunction was diagnosed in 44.6%of Child-Pugh A class patients,in 62%of Child B class and in 63.3%of Child C patients(P=0.028).The proportion of patients with higher diastolic dysfunction grades increases in more severe cirrhosis presentation(P<0.001).There was no difference between mean MELD scores in patients with and without diastolic dysfunction and in different diastolic dysfunction groups.In all studies diastolic dysfunction was more frequent in patients with ascites.CONCLUSION This systemic analysis suggests that left ventricle diastolic dysfunction is an attribute of liver cirrhosis which has not received sufficient attention from clinicians so far.Future suggestions of a comprehensive assessment of cardiac function in cirrhotic patients might provide a better prognosis for these patients and give hint for better understanding of the left ventricle diastolic dysfunction pathogenesis in liver cirrhosis.

Left to Right Extracardial Shunt to Control Hemorrhage of Ascending Aorta and Left Ventricle: A Report of 3 Cases

Presented in this paper are 3 cases of hemorrhage of ascending aorta and left ventricle after open heart surgery treated by extracardial bypass in our hospital from Oct. 1994 to Dec. 1995. Remained aneurysmal wall enclosing conduit graft was used as a sac bypassed to right atrium to form a extracardial left-toright shunt in order to control bleeding and the results turned out to be satisfactory. The bypass and hemodynamically ignorable shunt can close spontaneously without complications with recovery of coagulation system. The technique may find wide application in clinical practice.

Assessment of Left Atrial Function by Full Volume Real-time Three-dimensional Echocardiography and Left Atrial Tracking in Essential Hypertension Patients with Different Patterns of Left Ventricular Geometric Models

Objective To evaluate left atrial function in essential hypertension patients with different patterns of left ventricular geometric models by real-time three-dimensional echocardiography （RT-3DE） and left atrial tracking （EAT）.

Patient-Specific Echo-Based Fluid-Structure Interaction Modeling Study of Blood Flow in the Left Ventricle with Infarction and Hypertension

Understanding cardiac blood flow behaviors is of importance for cardiovascular research and clinical assessment of ventricle functions.Patient-specific Echo-based left ventricle(LV)fluid-structure interaction(FSI)models were introduced to perform ventricle mechanical analysis,investigate flow behaviors,and evaluate the impact of myocardial infarction(MI)and hypertension on blood flow in the LV.Echo image data were acquired from 3 patients with consent obtained:one healthy volunteer(P1),one hypertension patient(P2),and one patient who had an inferior and posterior myocardial infarction(P3).The nonlinear Mooney-Rivlin model was used for ventricle tissue with material parameter values chosen to match echo-measure LV volume data.Using the healthy case as baseline,LV with MI had lower peak flow velocity(30%lower at beginejection)and hypertension LV had higher peak flow velocity(16%higher at begin-filling).The vortex area(defined as the area with vorticity>0)for P3 was 19%smaller than that of P1.The vortex area for P2 was 12%smaller than that of P1.At peak of filling,the maximum flow shear stress(FSS)for P2 and P3 were 390%higher and 63%lower than that of P1,respectively.Meanwhile,LV stress and strain of P2 were 41%and 15%higher than those of P1,respectively.LV stress and strain of P3 were 36%and 42%lower than those of P1,respectively.In conclusion,FSI models could provide both flow and structural stress/strain information which would serve as the base for further cardiovascular investigations related to disease initiation,progression,and treatment strategy selections.Large-scale studies are needed to validate our findings.

Clinical Study on Preventing and Treating Left Ventricle Remodeling after Acute Myocardial Infarction with Integrative Chinese and Western Medicine

Objective: To explore the clinical efficacy of Xuefu Zhuyu (血府逐瘀, XFZY) oral liquid combined with western medicine (WM) in reversing left ventricle remodeling (LVR) after acute myocardial infarction (AMI) in patients and its therapeutic mechanism. Methods: Sixty patients conforming to criteria were divided into the treated group and WM control group with randomly stratified method. Thirty cases were assigned to each group, they were given XFZY + WM + general treatment and WM + general treatment respectively. Color Doppler ultrasonography was used to study the changes of LVR before and after treatment. Results: In both groups, before and after treatment the P value of such parameters as the changes of their left diastolic volume (LDV), left systolic volume (LSV), left ventricle ejection fraction (EF) was <0.05, suggesting that the difference of various parameters was significantly different; but when compared with the results of the 12th week after medications, the change of LDV, LSV, EF showed that the LDV, LSV of the treated group were lower than that of the control group, the EF of the treated group was higher than that of the control group, and the P value of various groups was all <0.05, suggesting that the different data of various groups showed significant difference. Conclusion: Conventional WM treatment and XFZY combined with WM could both, in treating AMI, effectively reverse the patients' LVR; yet the use of integrative Chinese and western medicine on reversing patients LVR showed even better results than that of simple WM treatment.

Effect of gestational protein restriction on left ventricle hypertrophy and heart angiotensin II signaling pathway in adult offspring rats

Maternal protein restriction may be a risk factor for cardiovascular disorders in adulthood. The RAS (renin-angiotensin-system) plays a pivotal role in cardiac remodeling. Components of the RAS, including angiotensin II (AngII) and its receptors type 1 (AT1R) and 2 (AT2R) are expressed in the heart. This study investigates whether gestational protein restriction alters the expression and localization of AT1R and AT2R and RAS signaling pathway proteins in parallel with left ventricle hypertrophy and systemic hypertension in male offspring. Dams were kept on normal (NP, 17% protein) or low (LP, 6% protein) protein diet during pregnancy. Systolic blood pressure (SBP) of male offspring was measured from the 8th to 16th week and left ventricles of 16-wk-old rats were processed for histology, morphometric, immunoblotting and immunohistochemistry. LP offspring showed a significant reduction in birth body weight and SBP increased significantly from the 8th week. Left ventricle mass and cardiomyocytes area were also significantly higher in LP animals. Widespread perivascular fibrosis was not detected in the heart tissue. Analysis by immunoblotting and immunohistochemistry demonstrated a significant enhance in cardiomyocyte expression of AT1R and ERK1 in LP offspring. Expression of PI3K in LP was significantly reduced in cardiomyocytes and in the intramural coronary wall, while AT2R expression was unchanged in the NP group. We also found reduced LP expression of JAK2 and STAT3. In conclusion, our data also suggest that changes in the RAS may play a role in the ventricular growth through upregulation of the AT1-mediated ERK1/2 response, despite unchanged AT2R expression.