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.

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.

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.

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.

Left Ventricle Failure and Blood Flow Estimation for Centrifugal Blood Pumps

This paper shows the blood flow control （FwC） performance to adjust rotational speed of an ICBP （implantable centrifugal blood pump） in order to provide an adequate flow to left ventricle in different patient conditions. ICBP is a totally implantable LVAD （left ventricular assist device） with ceramic bearings developed for long term circulatory assistance. FwC uses PI （proportional-integral） control to adjust rotational speed in order to provide blood flow. FwC does not use sensor for feedback, as there is an estimation system to provide blood flow measurement. Control strategy has being studied in a HCS （hybrid cardiovascular simulator） as a tool that allows the physical connection of ICBP during evaluation. In addition, HCS allows changes of some cardiovascular parameters in order to simulate specific heart disease： ejection fraction （10-25%） and heart rate （50-110 bpm）. FwC was able to adjust blood flow with steady error less than 2%. Results demonstrated that FwC is adequate to LVAD control irL different left ventricle failure conditions.

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

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.

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.

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.

Diagnostic Accuracy of Strain Imaging of the Left Ventricle in Detection of Obstructive Coronary Artery Disease

Background: Speckle tracking echocardiography using average global strain and strain rate (SR) parameters for early detection of high risk patients with coronary artery disease (CAD) has gained a substantial clinical interest. Objective: Assessment of the diagnostic accuracy of strain imaging of the left ventricle in detection of obstructive coronary artery disease. Methods: One hundred patients were enrolled. They were divided into 3 groups: Group I (n = 40 patients) presented with ST segment elevation myocardial infarction (STEMI), Group II (n = 40 patients) presented with non-ST segment elevation myocardial infarction (NSTEMI) or unstable angina (UA) and Group III (n = 20 patients) with normal coronary angiography served as a control group. All patients were subjected to 2D speckle tracking echocardiography (2D STE) to assess LV longitudinal strain and strain rate (SR). Sensitivity, specificity and diagnostic accuracy of 2D STE in prediction of CAD and its severity using Gensini score were assessed. Results: The mean age for Group I, II and III was 52.20 ± 11.83, 51.97 ± 14.53 and 52.75 ± 10.75 respectively. LV average global systolic strain (AGS) was significantly lower in group I and II when compared to group III. AGS and average global systolic SR showed significant direct correlation with Gensini score. The diagnostic accuracy of 2D STE in prediction of significant LAD stenosis was 92.5%, and it was 89.5% in prediction of 3 vessels CAD. Conclusion: Strain imaging using 2D STE can predict the territory and severity of CAD with high diagnostic accuracy and can be used as a simple noninvasive diagnostic tool to identify high risk CAD patients.

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.

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.

Hypertrophic cardiomyopathy and left ventricular non-compaction:Distinct diseases or variant phenotypes of a single condition?

Hypertrophic cardiomyopathy(HCM)is a genetically determined myocardial disease characterized by an increased thickness of the left ventricle(LV)wall that cannot be solely attributed to abnormal loading conditions.HCM may present with an intraventricular or LV outflow tract obstruction,diastolic dysfunction,myocardial fibrosis and/or ventricular arrhythmias.Differentiating HCM from other diseases associated with LV hypertrophy,such as hypertension,aortic stenosis,or LV non-compaction(LVNC),can at times be challenging.LVNC is defined by excessive LV trabeculation and deep recesses between trabeculae,often accompanied by increased LV myocardial mass.Previous studies indicate that the LVNC phenotype may be observed in up to 5%of the general population;however,in most cases,it is a benign finding with no impact on clinical outcomes.Nevertheless,LVNC can occasionally lead to LV systolic dysfunction,manifesting as a phenotype of dilated or non-dilated left ventricular cardiomyopathy,with an increased risk of thrombus formation and arterial embolism.In extreme cases,where LVNC is associated with a very thickened LV wall,it can even mimic HCM.There is growing evidence of an overlap between HCM and LVNC,including similar genetic mutations and clinical presentations.This raises the question of whether HCM and LVNC represent different phenotypes of the same disease or are,in fact,two distinct entities.

Automated Segmentation of Left Ventricle Using Local and Global Intensity Based Active Contour and Dynamic Programming

The aim of this work is to develop an improved region based active contour and dynamic programming based method for accurate segmentation of left ventricle （LV） from multi-slice cine short axis cardiac magnetic resonance （MR） images. Intensity inhomogeneity and weak object boundaries present in MR images hinder the segmentation accuracy. The proposed active contour model driven by a local Gaussian distribution fitting （LGDF） energy and an auxiliary global intensity fitting energy improves the accuracy of endocardial boundary detection. The weightage of the global energy fitting term is dynamically adjusted using a spatially varying weight function. Dynamic programming scheme proposed for the segmentation of epicardium considers the myocardium probability map and a distance weighted edge map in the cost matrix. Radial distance weighted technique and conical geometry are employed for segmenting the basal slices with left ventricle outflow tract （LVOT） and most apical slices. The proposed method is validated on a public dataset comprising 45 subjects from medical image computing and computer assisted interventions （MICCAI） 2009 segmentation challenge. The average percentage of good endocardial and epicardial contours detected is about 99%, average perpendicular distance of the detected good contours from the manual reference contours is 1.95 mm, and the dice similarity coefficient between the detected contours and the reference contours is 0.91. Correlation coefficient and the coefficient of determination between the ejection fraction measurements from manual segmentation and the automated method are respectively 0.9781 and 0.9567, for LV mass these values are 0.9249 and 0.8554. Statistical analysis of the results reveals a good agreement between the clinical parameters determined manually and those estimated using the automated method.

Seg-CapNet:A Capsule-Based Neural Network for the Segmentation of Left Ventricle from Cardiac Magnetic Resonance Imaging

Deep neural networks(DNNs)have been extensively studied in medical image segmentation.However,existing DNNs often need to train shape models for each object to be segmented,which may yield results that violate cardiac anatomical structure when segmenting cardiac magnetic resonance imaging(MRI).In this paper,we propose a capsulebased neural network,named Seg-CapNet,to model multiple regions simultaneously within a single training process.The Seg-CapNet model consists of the encoder and the decoder.The encoder transforms the input image into feature vectors that represent objects to be segmented by convolutional layers,capsule layers,and fully-connected layers.And the decoder transforms the feature vectors into segmentation masks by up-sampling.Feature maps of each down-sampling layer in the encoder are connected to the corresponding up-sampling layers,which are conducive to the backpropagation of the model.The output vectors of Seg-CapNet contain low-level image features such as grayscale and texture,as well as semantic features including the position and size of the objects,which is beneficial for improving the segmentation accuracy.The proposed model is validated on the open dataset of the Automated Cardiac Diagnosis Challenge 2017(ACDC 2017)and the Sunnybrook Cardiac Magnetic Resonance Imaging(MRI)segmentation challenge.Experimental results show that the mean Dice coefficient of Seg-CapNet is increased by 4.7%and the average Hausdorff distance is reduced by 22%.The proposed model also reduces the model parameters and improves the training speed while obtaining the accurate segmentation of multiple regions.

Fluid-structure interaction simulation of pathological mitral valve dynamics in a coupled mitral valve-left ventricle model

Background Understanding the interaction between the mitral valve(MV)and the left ventricle(LV)is very important in assessing cardiac pump function,especially when the MV is dysfunctional.Such dysfunction is a major medical problem owing to the essential role of the MV in cardiac pump function.Computational modelling can provide new approaches to gain insight into the functions of the MV and LV.Methods In this study,a previously developed LV-MV model was used to study cardiac dynamics of MV leaflets under normal and pathological conditions,including hypertrophic cardiomyopathy(HOCM)and calcification of the valve.The coupled LV-MV model was implemented using a hybrid immersed boundary/finite element method to enable assessment of MV haemodynamic performance.Constitutive parameters of the HOCM and calcified valves were inversely determined from published experimental data.The LV compensation mechanism was further studied in the case of the calcified MV.Results Our results showed that MV dynamics and LV pump function could be greatly affected by MV pathology.For example,the HOCM case showed bulged MV leaflets at the systole owing to low stiffness,and the calcified MV was associated with impaired diastolic filling and much-reduced stroke volume.We further demonstrated that either increasing the LV filling pressure or increasing myocardial contractility could enable a calcified valve to achieve near-normal pump function.Conclusion The modelling approach developed in this study may deepen our understanding of the interactions between the MV and the LV and help in risk stratification of heart valve disease and in silico treatment planning by exploring intrinsic compensation mechanisms.

Prenatal Diagnosis of an Apically Located Congenital Left Ventricular Aneurysm: A Rare Case

Congenital ventricular aneurysm is a very rare cardiac anomaly.A diagnosis can be made during the prenatal period using fetal echocardiography.This study presents a very rare apically located left ventricular aneurysm case,and the relevant literature was reviewed and discussed.In this case,a 35-year-old,gravida 2,parity 1 preg-nant woman at 24 weeks of gestation,displayed a wide aneurysmal image in the left ventricular apical wall on fetal echocardiography.There was a 1.79 mm muscular ventricular septal defect at the apical region of the interven-tricular septum.In the course of the color Doppler ultrasonography examination,an aberrantfibrous band within the left ventricle and consequent turbulentflow during systole were observed.The baby,born via cesarean section at 37 weeks of gestation,is now in its postnatal seventh month.However,during echocardiographic follow-ups,changes have been observed,including mild to moderate mitral insufficiency and a decrease in systolic function.Despite thesefindings,the clinical condition remains asymptomatic.It is of great importance to use a multidis-ciplinary approach in managing these rare cases that could lead to potential adverse outcomes during the antena-tal or postnatal periods.

Left Ventricular Systolic Intraventricular Flow Field Assessment in Hyperthyroidism Patients Using Vector Flow Mapping

Summary： Intraventricular hydrodynamics is considered an important component of cardiac function assessment. Vector flow mapping （VFM） is a novel flow visualization method to describe cardiac pathophysiological condition. This study examined use of new VFM and flow field for assessment of left ventricular （LV） systolic hemodynamics in patients with simple hyperthyroidism （HT）. Thirty-seven simple HT patients were enrolled as HT group, and 38 gender- and age-matched healthy volunteers as control group. VFM model was used to analyze LV flow field at LV apical long-axis view. The follow- ing flow parameters were measured, including peak systolic velocity （Vs）, peak systolic flow （Fs）, total systolic negative flow （SQ） in LV basal, middle and apical level, velocity gradient from the apex to the aortic valve （AV）, and velocity according to half distance （V1/2）. The velocity vector in the LV cavity, stream line and vortex distribution in the two groups were observed. The results showed that there were no significant differences in the conventional parameters such as left ventricular ejection fraction （LVEF）, left ventricular end-diastolic diameter （LVEDD） and left atrium diameter （LAD） between HT group and control group （P〉0.05）. Compared with the control group, a brighter flow and more vortexes were detected in HT group. Non-uniform distribution occurred in the LV flow field, and the stream lines were discontinuous in HT group. The values of Vs and Fs in three levels, SQ in middle and basal levels, AV and V1/2 were higher in HT group than in control group （P〈0.01）. AV was positively correlated with serum free thyroxin （FT4） （r=0.48, P〈0.01）. Stepwise multiple regression analysis showed that LVEDD, FT4, and body surface area （BSA） were the influence factors of △V. The unstable left ventricular sys- tolic hydrodynamics increased in a compensatory manner in simple PIT patients. The present study in- dicated that VFM may be used for early detection of abnormal ventricle contraction in clinical settings.

Evaluation of Left Ventricular Function by Three-Dimensional Speckle-Tracking Echocardiography in Patients with Chronic Kidney Failure

Objective:To establish a quantitative evaluation of the left ventricle's systolic function in patients with chronic kidney failure(CKF)by three-dimensional speckle-tracking echocardiography.Methods:Two-dimensional and three-dimensional transthoracic echocardiography was performed on 30 patients with CKF.The ejection fraction,mass and global peak longitudinal strain,global circumferential strain,global area strain,and global radial strain of the left ventricle were calculated.Results:The ejection fraction,mass and global peak longitudinal strain(GLS),global circumferential strain(GCS),global area strain(GAS),and global radial strain(GRS)in the CKF group were significantly lower than those in the control group.Simultaneously,the GLS,GCS,GAS and GRS were well correlated with the ejection fraction.For patients with normal ejection fraction in the CKF group,the GLS,GCS,GAS and GRS were lower than those in the control group,while the left ventricular mass was significantly higher in CKF patients than in the control group.For patients with hypertension in the CKF group,ejection fraction,GLS,GCS,GAS and GRS calculated using three-dimensional echocardiography were significantly lower than those in patients with normal blood pressure;however,the myocardial mass was higher.Conclusions:The parameters(GLS,GCS,GAS and GRS)calculated using three-dimensional speckle-tracking software were lower in the CKF group.Simultaneously,the left ventricular mass was higher in CFK patients than in the control group,thus showing that the myocardial contraction function was impaired and that myocardial remodeling had occurred.