Post-Discharge eLearning Platform for Cardiac Patients: Developing the Format of the Educational Units and Recording the Contents

Myocardial infarction patients face an increased risk of cardiovascular problems. This risk can be reduced by adjusting one’s lifestyle. However, once discharged from the hospital and faced with self-care at home the patient faces a loss of adequate information and diminishing motivation with time after infarction the event. There is a gap of two weeks between being released from the hospital and the patient having any chance of joining organised cardiac rehabilitation programmes, if these are organised by the health system at all. Unfortunately, by that time the highest motivation for lifestyle change has already been lost. An eLearning platform has been put forward to bridge this period, however, the content needs to be carefully prepared to educate and motivate the patient and their family. By analysing how health information is acquired over the Internet today, and by applying social-cognitive learning and storytelling into educational videos we developed a format of an effective educational unit. In order to develop an essential set of educational units seven interviews were recorded with members of medical teams and five with patients who had coronary disease, of which two were with their partners who were their informal caregivers. The format of the educational unit was designed as such that it can be viewed in 4-8 minutes and was composed of three videos featuring peer-patients and medical team members. The videos were accompanied by a short text of up to 50 words, illustrations or quiz questions. From the recorded video material 60 educational videos were edited and used to compose 20 educational units for patients with coronary disease. Legal issues regarding Rights of Publishing and General Data Protection Regulation issues were solved and backend data analytics was developed. Thus, the platform was prepared for next step which will be a large random clinical study

Three-dimensional mapping of mechanical activation patterns, contractile dyssynchrony and dyscoordination by two-dimensional strain echocardiography: Rationale and design of a novel software toolbox

<p>Abstract</p> <p>Background</p> <p>Dyssynchrony of myocardial deformation is usually described in terms of variability only (e.g. standard deviations SD's). A description in terms of the spatio-temporal distribution pattern (vector-analysis) of dyssynchrony or by indices estimating its impact by expressing dyscoordination of shortening in relation to the global ventricular shortening may be preferential. Strain echocardiography by speckle tracking is a new non-invasive, albeit 2-D imaging modality to study myocardial deformation.</p> <p>Methods</p> <p>A post-processing toolbox was designed to incorporate local, speckle tracking-derived deformation data into a 36 segment 3-D model of the left ventricle. Global left ventricular shortening, standard deviations and vectors of timing of shortening were calculated. The impact of dyssynchrony was estimated by comparing the end-systolic values with either early peak values only (early shortening reserve ESR) or with all peak values (virtual shortening reserve VSR), and by the internal strain fraction (ISF) expressing dyscoordination as the fraction of deformation lost internally due to simultaneous shortening and stretching. These dyssynchrony parameters were compared in 8 volunteers (NL), 8 patients with Wolff-Parkinson-White syndrome (WPW), and 7 patients before (LBBB) and after cardiac resynchronization therapy (CRT).</p> <p>Results</p> <p>Dyssynchrony indices merely based on variability failed to detect differences between WPW and NL and failed to demonstrate the effect of CRT. Only the 3-D vector of onset of shortening could distinguish WPW from NL, while at peak shortening and by VSR, ESR and ISF no differences were found. All tested dyssynchrony parameters yielded higher values in LBBB compared to both NL and WPW. CRT reduced the spatial divergence of shortening (both vector magnitude and direction), and improved global ventricular shortening along with reductions in ESR and dyscoordination of shortening expressed by ISF.</p> <p>Conclusion</p> <p>Incorporation of local 2-D echocardiographic deformation data into a 3-D model by dedicated software allows a comprehensive analysis of spatio-temporal distribution patterns of myocardial dyssynchrony, of the global left ventricular deformation and of newer indices that may better reflect myocardial dyscoordination and/or impaired ventricular contractile efficiency. The potential value of such an analysis is highlighted in two dyssynchronous pathologies that impose particular challenges to deformation imaging.</p

Three-Wall Segment (TriSeg) Model Describing Mechanics and Hemodynamics of Ventricular Interaction

A mathematical model (TriSeg model) of ventricular mechanics incorporating mechanical interaction of the left and right ventricular free walls and the interventricular septum is presented. Global left and right ventricular pump mechanics were related to representative myofiber mechanics in the three ventricular walls, satisfying the principle of conservation of energy. The walls were mechanically coupled satisfying tensile force equilibrium in the junction. Wall sizes and masses were rendered by adaptation to normalize mechanical myofiber load to physiological standard levels. The TriSeg model was implemented in the previously published lumped closed-loop CircAdapt model of heart and circulation. Simulation results of cardiac mechanics and hemodynamics during normal ventricular loading, acute pulmonary hypertension, and chronic pulmonary hypertension (including load adaptation) agreed with clinical data as obtained in healthy volunteers and pulmonary hypertension patients. In chronic pulmonary hypertension, the model predicted right ventricular free wall hypertrophy, increased systolic pulmonary flow acceleration, and increased right ventricular isovolumic contraction and relaxation times. Furthermore, septal curvature decreased linearly with its transmural pressure difference. In conclusion, the TriSeg model enables realistic simulation of ventricular mechanics including interaction between left and right ventricular pump mechanics, dynamics of septal geometry, and myofiber mechanics in the three ventricular walls

Visualization of Myocardial Strain Pattern Uniqueness with Respect to Activation Time and Contractility: A Computational Study

Speckle tracking echography is used to measure myocardial strain patterns in order to assess the state of myocardial tissue. Because electro-mechanical coupling in myocardial tissue is complex and nonlinear, and because of the measurement errors the uniqueness of strain patterns is questionable. In this study, the uniqueness of strain patterns was visualized in order to revel characteristics that may improve their interpretation. A computational model of sarcomere mechanics was used to generate a database of 1681 strain patterns, each simulated with a different set of sarcomere parameters: time of activation (TA) and contractility (Con). TA and Con ranged from &minus;100 ms to 100 ms and 2% to 202% in 41 steps respectively, thus forming a two-dimensional 41 &times; 41 parameter space. Uniqueness of the strain pattern was assessed by using a cohort of similar strain patterns defined by a measurement error. The cohort members were then visualized in the parameter space. Each cohort formed one connected component (or blob) in the parameter space; however, large differences in the shape, size, and eccentricity of the blobs were found for different regions in the parameter space. The blobs were elongated along the TA direction (&plusmn;50 ms) when contractility was low, and along the Con direction (&plusmn;50%) when contractility was high. The uniqueness of the strain patterns can be assessed and visualized in the parameter space. The strain patterns in the studied database are not degenerated because a cohort of similar strain patterns forms only one connected blob in the parameter space. However, the elongation of the blobs means that estimations of TA when contractility is low and of Con when contractility is high have high uncertainty

Visualization of myocardial strain pattern uniqueness with respect to activation time and contractility

Speckle tracking echography is used to measure myocardial strain patterns in order to assess the state of myocardial tissue. Because electro-mechanical coupling in myocardial tissue is complex and nonlinear, and because of the measurement errors the uniqueness of strain patterns is questionable. In this study, the uniqueness of strain patterns was visualized in order to revel characteristics that may improve their interpretation. A computational model of sarcomere mechanics was used to generate a database of 1681 strain patterns, each simulated with a different set of sarcomere parameters: time of activation (TA) and contractility (Con). TA and Con ranged from -100 ms to 100 ms and 2% to 202% in 41 steps respectively, thus forming a two-dimensional 41 x 41 parameter space. Uniqueness of the strain pattern was assessed by using a cohort of similar strain patterns defined by a measurement error. The cohort members were then visualized in the parameter space. Each cohort formed one connected component (or blob) in the parameter spacehowever, large differences in the shape, size, and eccentricity of the blobs were found for different regions in the parameter space. The blobs were elongated along the TA direction (±50 ms) when contractility was low, and along the Con direction (±50%) when contractility was high. The uniqueness of the strain patterns can be assessed and visualized in the parameter space. The strain patterns in the studied database are not degenerated because a cohort of similar strain patterns forms only one connected blob in the parameter space. However, the elongation of the blobs means that estimations of TA when contractility is low and of Con when contractility is high have high uncertainty

Uniqueness of local myocardial strain patterns with respect to activation time and contractility of the failing heart: a computational study

Abstract Background Myocardial deformation measured by strain is used to detect electro-mechanical abnormalities in cardiac tissue. Estimation of myocardial properties from regional strain patterns when multiple pathologies are present is therefore a promising application of computer modelling. However, if different tissue properties lead to indistinguishable strain patterns (‘degeneracy’), the applicability of any such method will be limited. We investigated whether estimation of local activation time (AT) and contractility from myocardial strain patterns is theoretically possible. Methods For four different global cardiac pathologies local myocardial strain patterns for 1025 combinations of AT and contractility were simulated with a computational model (CircAdapt). For each strain pattern, a cohort of similar patterns was found within estimated measurement error using the sum of least-squared differences. Cohort members came from (1) the same pathology only, and (2) all four pathologies. Uncertainty was calculated as accuracy and precision of cohort members in parameter space. Connectedness within the cohorts was also studied. Results We found that cohorts drawn from one pathology had parameters with adjacent values although their distribution was neither constant nor symmetrical. In comparison cohorts drawn from four pathologies had disconnected components with drastically different parameter values and accuracy and precision values up to three times higher. Conclusions Global pathology must be known when extracting AT and contractility from strain patterns, otherwise degeneracy occurs causing unacceptable uncertainty in derived parameters

Detection of physiological control inputs preload and afterload from intrinsic pump parameters in total artificial heart

Background: In the total artificial heart (TAH), the inputs to the physiological control unit, preload, and afterload, are detected from intrinsic pump parameters (e.g., motor current). Within this study, their detection techniques are developed, and their reliability in pre- and afterload prediction is mapped for a broad range of cardiovascular system states. Methods: We used ReinHeart TAH which is a fully implantable TAH with a plunger coil drive that is alternately emptying the left and right chambers. From the coil currents we first derived a force generated by the piston with respect to its position and then analyzed its pattern to detect (1) preload—chamber filling, found as piston position at begin ejection and (2) afterload—mean outflow pressures, determined as linearly calibrated average piston force during ejection. TAH is then integrated into a mock loop circulation (MLC) which is set to 135 different steady operating points varying in chamber filling (0%–100%, five steps), mean outflow pressures (system circulation: 60–90–120 mm Hg, pulmonary circulation: 15–30-45 mm Hg), and heart cycle duration (171–600 ms in seven non-equidistant steps). The detected preload and afterload are compared to MLC set values, and the errors are mapped. Results: Respectively for the left and right chambers, the preload was detectable in 134 and 118 operating points and the mean error was ±3% and ±2%. The afterload was detectable in 135 and 87 operating points and the mean error was 37% and 30% respectively for left and right circulation. The operational points that are further away from homeostatic equilibrium values generally yielded larger errors. The largest errors were observed for right circulation at long cycle duration, low afterload, and low filling. Conclusions: The study yields reliable preload estimation in a broad range of physiological states, particularly for left circulation. Detection of afterload needs further improvements. The study revealed a need for piston movement optimization within the ReinHeart TAH during the early phase of systole

Uporaba podatkov o gospodarski javni infrastrukturi na področju prostorskega načrtovanja za občinsko raven : The Use Of The Cadastre Of Public Infrastructure Data In The Field Of Spatial Planning At Community Level

SI: Prispevek prikazuje različne vidike uporabe podatkov o gospodarski javni infrastrukturi (GJI) na področju prostorskega načrtovanja za občinsko raven z zornega kota prostorskega načrtovalca. Predstavljena je vlogo in osnovne zahteve glede podatkov o GJI pri pripravi posameznih vrst prostorske dokumentacije. Uporaba podatkov o GJI je prikazana z vidika podrobnejših namenov uporabe, (ne)pomembnosti njihovih posameznih lastnosti in problematike pri njihovi uporabi. Podani so tudi predlogi za izboljšanje uporabe podatkov o GJI na zadevnem področju. EN: The paper describes different ways of using public infrastructure (PI) data in the field of spatial planning at the community level from the point of view of a spatial planner. The authors describe the role and basic demands related to PI data when preparing different sorts of spatial documentation. The use of PI data is described from the following aspects: detailed purposes of data use, (un)importance of specific characteristics of data and problems of data use. The paper also brings some suggestions how to improve the use of PI data in a given field of interest