PurposeIntraventricular blood flow dynamics are associated with cardiac function. Accurate, noninvasive, and easy assessments of hemodynamic quantities (such as velocity, vortex, and pressure)... Show morePurposeIntraventricular blood flow dynamics are associated with cardiac function. Accurate, noninvasive, and easy assessments of hemodynamic quantities (such as velocity, vortex, and pressure) could be an important addition to the clinical diagnosis and treatment of heart diseases. However, the complex time-varying flow brings many challenges to the existing noninvasive image-based hemodynamic assessments. The development of reliable techniques and analysis tools is essential for the application of hemodynamic biomarkers in clinical practice.MethodsIn this study, a time-resolved particle tracking method, Shake-the-Box, was applied to reconstruct the flow in a realistic left ventricle (LV) silicone model with biological valves. Based on the obtained velocity, 4D pressure field was calculated using a Poisson equation-based pressure solver. Furthermore, flow analysis by proper orthogonal decomposition (POD) of the 4D velocity field has been performed.ResultsAs a result of the Shake-the-Box algorithm, we have extracted: (i) particle positions, (ii) particle tracks, and finally, (iii) 4D velocity fields. From the latter, the temporal evolution of the 3D pressure field during the full cardiac cycle was obtained. The obtained maximal pressure difference extracted along the base-to-apex was about 2.7 mmHg, which is in good agreement with those reported in vivo. The POD analysis results showed a clear picture of different scale of vortices in the pulsatile LV flow, together with their time-varying information and corresponding kinetic energy content. To reconstruct 95% of the kinetic energy of the LV flow, only the first six POD modes would be required, leading to significant data reduction.ConclusionsThis work demonstrated Shake-the-Box is a promising technique to accurately reconstruct the left ventricle flow field in vitro. The good spatial and temporal resolutions of the velocity measurements enabled a 4D reconstruction of the pressure field in the left ventricle. The application of POD analysis showed its potential in reducing the complexity of the high-resolution left ventricle flow measurements. For future work, image analysis, multi-modality flow assessments, and the development of new flow-derived biomarkers can benefit from fast and data-reducing POD analysis. Show less
This thesis is the result of several studies into the clinical and echocardiographic outcome of both open and hybrid surgical ventricular reconstruction for the treatment of ischemic cardiomyopathy... Show moreThis thesis is the result of several studies into the clinical and echocardiographic outcome of both open and hybrid surgical ventricular reconstruction for the treatment of ischemic cardiomyopathy. Additionally, predictors for a favorable outcome and important associated issues such as management and late outcome of functional mitral regurgitation and the use of LV ejection fraction as a selection criterium for indication for a implantable cardioverter defibrillator for the primary prevention ofventricular arrhythmias after surgical ventricular reconstruction were studied. In chapter 2 the early and late outcome of different types of open left ventricular reconstruction surgery by means of a meta-analysis are presented. Chapter 3 describesthe use of echocardiographic wall motion score index to predict mortality and functional results after surgical ventricular reconstruction for advanced ischemic heart failure. In chapter 4 the management of functional mitral regurgitation during left ventricular reconstruction is presented followed by a landmark analysis into the 10-year outcome of functional mitral regurgitation after left ventricular reconstruction. Chapter 5 discusses the use of the improved LV ejection fraction after SVR as an indication for a implantable cardioverter defibrillator for the primary prevention of ventricular arrhythmias after surgical ventricular reconstruction in heart failure patients. Chapter 6 discusses the early experience with a minimal-invasive hybrid transcatheter surgical ventricular reconstruction technique. First the technique of hybrid transcatheter left ventricular reconstruction is described. Followed by the preliminary results of this technique from 2 cardiac centres in the Netherland. Finally, the multicenter European results of hybrid less invasive reconstruction on clinical, functional and echocardiographic outcome are presented. Show less
The objectives of this thesis were to elucidate the pathogenesis of metabolic heart disease, evaluate the associated changes in myocardial structure and contractile function, and determine the long... Show moreThe objectives of this thesis were to elucidate the pathogenesis of metabolic heart disease, evaluate the associated changes in myocardial structure and contractile function, and determine the long-term prognostic implications of subclinical myocardial dysfunction on all-cause mortality. Show less
Fortuni, F.; Butcher, S.C.; Kley, F. van der; Lustosa, R.P.; Karalis, I.; Weger, A. de; ... ; Marsan, N.A. 2021
Background: Left ventricular myocardial work (LVMW) is a novel method to assess left ventricular (LV) function using pressure-strain loops that takes into consideration LV afterload. The estimation... Show moreBackground: Left ventricular myocardial work (LVMW) is a novel method to assess left ventricular (LV) function using pressure-strain loops that takes into consideration LV afterload. The estimation of LV afterload in patients with severe aortic stenosis (AS) may be challenging, and no study so far has investigated LVMW in this setting. The aim of this study was to develop a method to calculate LVMW in patients with severe AS and to analyze its relationship with heart failure symptoms.Methods: Indices of LVMW were calculated in 120 patients with severe AS who underwent transcatheter aortic valve replacement and invasive LV and aortic pressure measurements. LV systolic pressure was also derived by adding the mean aortic valve gradient to the aortic systolic pressure. LV global longitudinal strain and echocardiography-derived LV systolic pressure were then incorporated to construct pressure-strain loops of the left ventricle.Results: An excellent correlation was observed between LVMW indices calculated using the invasive and echocardiography-derived LV systolic pressure. Patients in New York Heart Association functional class III or IV (n = 97 [73%]) had lower LV global longitudinal strain, LV global work index, LV global constructive work, and right ventricular free wall strain compared with those in New York Heart Association functional class I or II. In contrast to LV global longitudinal strain, LV global work index (odds ratio per 100 mm Hg% increase, 0.91; 95% CI, 0.85-0.98; P = .012) and LV global constructive work showed independent associations with New York Heart Association functional class III or IV heart failure symptoms.Conclusions: The calculation of echocardiography-based LVMW indices is feasible in patients with severe AS. In particular, LV global work index and global constructive work showed independent associations with heart failure symptoms and may provide additional information on myocardial remodeling and function in patients with severe AS. Show less
BackgroundIn the workup of a pediatric patient with pericarditis we found evidence of a pseudo-aneurysm of the left ventricle, which is a rare complication of purulent pericarditis.Case... Show moreBackgroundIn the workup of a pediatric patient with pericarditis we found evidence of a pseudo-aneurysm of the left ventricle, which is a rare complication of purulent pericarditis.Case presentationWe present a case of a six-year-old girl who was diagnosed with pericarditis and a fistula between the pericardial and the intra-luminal space of the left ventricle of the heart. She was successfully treated with antibiotics and cardio-thoracic surgery. We found 23 published cases (21 with follow-up) of infectious pseudo-aneurysm of the heart, of which 19 underwent surgery, 5 had fatal outcome, and 2 who refused surgery survived. The majority of cases were associated with Staphylococcus aureus. The exact mechanisms of this rare complication remain unknown.ConclusionsA pseudo-aneurysm of the left ventricle is a rare and not well understood complication of a purulent pericarditis most commonly caused by Staphylococcus aureus infection. Because of risk of rupture, surgical intervention is advised. Show less
T.B. le; Elbaz, M.S.M.; Geest, R.J. van der; Sotiropoulos, F. 2019
Mitral valve (MV) leaflets affect the formation, growth, and decay of vortices in the left ventricle (LV) during diastolic filling. The shape and motion of MV leaflets are simplified in most... Show moreMitral valve (MV) leaflets affect the formation, growth, and decay of vortices in the left ventricle (LV) during diastolic filling. The shape and motion of MV leaflets are simplified in most studies due to computational restrictions. In this study, we present a newly developed mathematical method to model the dynamic movement of valve leaflets and annulus, which is based on in vivo data obtained with magnetic resonance imaging (MRI). In the present method, we solve a boundary value problem where the MV surface is initially unknown. The resultant MV shapes are included in a dynamic motion model of the LV to assess the change of intraventricular flow patterns. To estimate the effects of the MV on left intraventricular flow, a LV model without MV leaflets was also simulated for comparison. Our study showed that the presence of the MV and the shape of its leaflets significantly altered the formation and evolution of vortex structures in the LV. The various MV leaflet shapes accelerate the transvalvular flow distinctly, leading to different formation and development of vortex structures. Show less
In this thesis we aim at automating the analysis of 3D echocardiography, mainly targeting the functional analysis of the left ventricle. Manual analysis of these data is cumbersome, time-consuming... Show moreIn this thesis we aim at automating the analysis of 3D echocardiography, mainly targeting the functional analysis of the left ventricle. Manual analysis of these data is cumbersome, time-consuming and is associated with inter-observer and inter-institutional variability. Methods for reconstruction of 3D echocardiographic images from fast rotating ultrasound transducers is presented and methods for analysis of 3D echocardiography in general, using tracking, detection and model-based segmentation techniques to ultimately fully automatically segment the left ventricle for functional analysis. We show that reliable quantification of left ventricular volume and mitral valve displacement can be achieved using the presented techniques. Show less
We have developed several methods for automated analysis of echocardiographic images. This thesis describes these methods and their evaluation and use. It is shown that semiautomatic detection... Show moreWe have developed several methods for automated analysis of echocardiographic images. This thesis describes these methods and their evaluation and use. It is shown that semiautomatic detection based on Dynamic Programming and Pattern Matching provides a useful and reliable way of analyzing 2D echocardiographic sequences of different cross sections. Main conclusion is that the new detection tools based on statistical models (Active Appearance Models) provide superior possibilities for automated analysis of echocardiographic images, since they are capable of realistically modeling both the typical problems and artifacts of cardiac ultrasound and the variability between patients. Also, these tools can be extended towards multi-view and multi-stage applications (e.g. stress echo), higher dimensions (3D echo), and simultaneous detection of multiple structures (LV, RV, atria, epicardium, valves). They also offer possibilities for computer-aided diagnosis, such as wall motion abnormality classification (stress echo and Cardiac Resynchronization Therapy). Further development and integration with other border detection and tracking approaches is certainly feasible and will offer a range of new research opportunities. The difficulties have not yet been completely overcome, but we are confident that fully automated, reliable analysis of echocardiographic images will eventually become a definite reality. Show less
