Three-dimensional Heart Model Research Articles

Delayed coronary artery stenosis: a rare complication of the left atrial clipping device.

A clipping device may impinge on the coronary artery following left atrial appendage occlusion during cardiac surgery, causing rare cardiac ischaemia perioperatively. This report highlights a case of delayed severe coronary artery stenosis resulting in ventricular fibrillation 2 months after cardiac surgery with the implantation of a left atrial clipping device. Following a percutaneous coronary intervention, the patient underwent clip removal surgery. Postoperative three-dimensional heart model verification revealed that the base of the left atrial appendage was more dorsal than usual, thereby increasing the potential risk of the clip impinging on the coronary artery. We should remember that this rare complication can occur after left atrial clipping, either in the early postoperative period or later.

Prespecialist perceptions of three-dimensional heart models in anatomical education.

This article aims to discuss the use of three-dimensional (3D) printed models of vascular variation cases as an educational tool for undergraduate and postgraduate anatomy students. This advanced study involved ten anatomy assistants who were provided with five distinct cases of congenital cardiovascular variations, each accompanied by a computed tomography angiography (CT-A) and 1:1 solid model format. The residents were asked to generate perceptions for both formats and then compare these perceptions based on identifying the variation, defining the structural features, and evaluating relevant educational perspectives. The vascular origin measurement values compared to the statistically evaluated real values of the related cases showed that models were 1:1 identical copies. Qualitative assessment feedback from five stations supported the usefulness of 3D models as educational tools for organ anatomy, simulation of variational structures, and overall medical education and anatomy training. Models showcasing different anatomical variations such as aortic arch with Type 2 pattern, a right-sided aortic arch with Type 2 pattern, an aberrant right subclavian artery, arteria lusoria in thorax, and a left coronary artery originating from pulmonary trunk in an Alcapa type pattern allow for better analysis due to their complex anatomies, thus optimizing the study of variation-specific anatomy. The perception level in the 3D model contained higher points in all of the nine parameters, namely identification of cardiovascular variations, defining the vessel with anomaly, aortic arch branch count and appearance order, feasibility of using it in peers and student education. 3D models received a score 9.1 points, while CT-A images were rated at 4.8 out of 10. 3D printed anatomical models of variational cardiovascular anatomy serve as essential components of anatomy training and postgraduate clinical perception by granting demonstrative feedback and a superior comprehension of the visuospatial relationship between the anatomical structures.

Utility of three-dimensional virtual and printed models for veterinary student education in congenital heart disease

Introduction: Congenital heart disease (CHD) is a common heart defect that can be present in small and large animals at birth. Student understanding of normal and abnormal cardiac anatomy is imperative for proper diagnosis and management of CHD. Objectives were to create and use three-dimensional (3D) heart models during a workshop to understand veterinary student perception of 3D models for CHD education. We hypothesized that 3D models would enhance student understanding of CHD, and students would prefer 3D models during cardiac education. Materials and Methods: Computed tomography angiography datasets from canine patent ductus arteriosus were used to create 3D models. Segmentation and computer-aided design were performed. Virtual overlays of 3D models were displayed onto two-dimensional (2D) thoracic radiographs. Stereolithography files were fabricated by a 3D printer. Students participated in a CHD workshop consisting of 2D and 3D teaching stations. Self-assessment surveys before and after the workshop were completed. Results: Twenty-two veterinary students attended the workshop. The 3D-printed models were found to be the most helpful teaching modality based on students’ perception. The 3D-printed model (P < 0.0001) and the 3D digital model (P < 0.0001) were perceived to be significantly more helpful than the 2D radiograph station. All students strongly agreed (15/22) or agreed (7/22) that virtual models overlayed onto 2D radiographs enhanced their spatial recognition of anatomic structures. All students strongly agreed (17/22) and agreed (5/22) that the CHD workshop was a valuable learning opportunity. Conclusion: Creation of virtual and fabricated 3D heart models is feasible. Three-dimensional models may be helpful when understanding spatial recognition of cardiovascular anatomy on thoracic radiographs. We advocate using 3D heart models during CHD education.

Virtual reality visualization of the right and left heart chambers anatomical position

Objective(s). To create a normal heart virtual model and visualize the anatomical position of the right and left chambers.&#x0D; Methods. The material for the investigation was cardiac CT scan results of a young healthy man. From these data, a three-dimensional heart model was created and anatomical position of the right and left chambers investigated.&#x0D; Results. Three-dimensional model of a normally formed, normally located heart was created. Segmentation, rotation of the virtual model, virtual horizontal dissection at the level of the middle of the interventricular septum were carried out, the created model was rotated in virtual reality. It was found that in the anatomically correct position the right chambers of the heart are located in front, and the left chambers are located behind.&#x0D; Conclusion. Virtual heart reconstruction reproduces digital data taken from a living person, so virtual reality shows the functioning structure of the heart and its chambers. In the anatomical position of the heart, the right atrium and ventricle are located ventrally, and the left atrium and ventricle are located dorsally. It is advisable for morphologists, cardiologists, and surgeons to take into account the identified discrepancies between the terms and the actual location of the heart chambers.

Influence of left atrial expansion and decreased interventricular septal wall motion following a weakened atrial kick on brain natriuretic peptide secretion in early-stage heart failure

Abstract Background The secretion of brain natriuretic peptide (BNP) by left ventricular (LV) myocytes increases even in patients with normal LV function. Currently, the cause of BNP increase in patients with stages A and B chronic heart failure remains unknown. Purpose To investigate the increase of BNP in early-stage, asymptomatic heart failure. Methods Consecutive patients (N=188; mean age: 68±11 years; body mass index: 23.0±3.9 kg/m2, female/male: 88/100) with heart failure (stages A and B), including non-valvular atrial fibrillation (NVAF), and LV ejection fraction &amp;gt;50% with estimated glomerular filtration rate &amp;gt;30% were recruited in this study. The echocardiographic parameters of LV systolic function (e.g., LV endo-diastolic/endo-systolic volume and ejection fraction) or diastolic markers (e.g., E/A ratio calculated from the trans mitral flow velocity and E/e' ratio), in addition to the data obtained from tissue Doppler images, were evaluated. LA volume was obtained from a three-dimensional heart model. Moreover, LV and left atrial (LA) global longitudinal strains were evaluated. The BNP levels measured within 1 month from echocardiographic examination were compared with the echocardiographic markers, in addition to an estimated glomerular filtration rate. Results BNP was elevated in patients with NVAF (NVAF, median: 63.0 pg/ml [quartile: 33.2–74.7 pg/ml]; non-NVAF, median: 25.6 pg/ml [quartile: 13.5–50.8 pg/ml]; p=0.0015) and patients with stage B heart failure (stage B, median: 41.7 pg/ml [quartile: 21.5–67.5 pg/ml]; stage A, median: 23.4 pg/ml [quartile: 11.7–39.0 pg/ml]; p=2.99E-05). The presence of hypertension and the sex of patients did not lead to significant differences in this population. The LA volume corrected by the body surface area was well correlated with the BNP value (r=0.55; 95% confidence interval [CI]: 0.44–0.64; p=4.42E-16) and age (r=0.51; 95% CI: 0.40–0.61; p=4.64E-14). LA global longitudinal strain (r=−0.42; 95% CI: −0.53 to −0.29; p=3.05E-09) and the velocity of interventricular septum during atrial contraction (r=−0.40; 95% CI: −0.51 to −0.27; p=1.84E-08) were also correlated with BNP elevation. However, the markers of diastolic and systolic function of LV were not correlated with BNP increase in patients with subclinical heart failure. Multivariate analysis revealed that LA volume (β: 0.991; 95% CI: 0.682–1.299; p=1.85E-09), stage B heart failure (β: 0.116; 95% CI: 0.016–0.216; p=0.023), age (β: 0.013; 95% CI: 0.008–0.018; p=6.414E-07), body mass index (β: −0.020; 95% CI: −0.033 to 0.007; p=0.002), and a decrease in the velocity of interventricular septum during atrial contraction (β: −0.048; 95% CI: −0.070 to −0.026; p=2.683E-05) contributed to the increase in BNP. Conclusion LA enlargement with no relation to diastolic function, age, and diminishment of interventricular motion caused by atrial contraction may be sensitive markers of BNP secretion in patients with subclinical stage, asymptomatic heart failure. Funding Acknowledgement Type of funding sources: None.

Left ventricle assessment by three-dimensional HeartModel software in different types of mitral valve prolapse (Barlow's disease and fibroelastic deficiency) with severe mitral regurgitation.

Mitral valve prolapse (MVP) is the most common cause of isolated mitral regurgitation (MR) requiring surgical repair. Therapeutic interventions should be considered before irreversible left ventricular (LV) dysfunction in asymptomatic patients. Measurement of LV volume and function is very important. Because of two-dimensional (2D) echocardiography limitations, three-dimensional (3D) measurement is preferred on the strength of its speed, accuracy, and reproducibility, which are comparable with those of magnetic resonance imaging (MRI). This study was conducted between April 2018 and February 2019 on 50 patients with different MVP types and severe MR scheduled for valve surgery at Rajaie Cardiovascular Research Center, Tehran, Iran, with the aid of the HeartModelAnatomical intelligence (A.I.) (EPIQ 7: new 3D software) for measurement of LV volume indices and function. Patients with the Barlow syndrome had a greater drop in LV ejection fraction (LVEF) than those with fibroelastic deficiency (FED) (57.05% ± 6.00% vs. 65.00% ± 4.08%; P = 0.001). LV volume was larger in patients with flail mitral valve (MV) than in those with non-flail MV (165 cc vs. 118 cc; P = 0.001). LVEF declined more in patients with the involvement of both leaflets than in those with the involvement of the anterior leaflet alone (56.00% ± 7.10% vs. 57.70% ± 4.30%; P = 0.021). The LVEF drop was more remarkable in patients with the Barlow syndrome (both flail and non-flail MV) than in those with FED. It is, therefore, advisable that such patients be monitored more meticulously via the 3D HeartModelA.I. method in terms of LVEF and LV size to prevent irreversible effects on LV function and to reduce mortality.

Quantified growth of the human embryonic heart.

ABSTRACTThe size and growth patterns of the components of the human embryonic heart have remained largely undefined. To provide these data, three-dimensional heart models were generated from immunohistochemically stained sections of ten human embryonic hearts ranging from Carnegie stage 10 to 23. Fifty-eight key structures were annotated and volumetrically assessed. Sizes of the septal foramina and atrioventricular canal opening were also measured. The heart grows exponentially throughout embryonic development. There was consistently less left than right atrial myocardium, and less right than left ventricular myocardium. We observed a later onset of trabeculation in the left atrium compared to the right. Morphometry showed that the rightward expansion of the atrioventricular canal starts in week 5. The septal foramina are less than 0.1 mm2 and are, therefore, much smaller than postnatal septal defects. This chronological, graphical atlas of the growth patterns of cardiac components in the human embryo provides quantified references for normal heart development. Thereby, this atlas may support early detection of cardiac malformations in the foetus.This article has an associated First Person interview with the first author of the paper.

A APPLICATION OF 3D HEART MODELS CREATED ON DICOM DATA IN MEDICAL PRACTICE

Three-dimensional printing (3D printing, additive manufacturing, rapid prototyping) is a technology of a physical object creation from digital model by layered addition of material. Additive technologies differ from mass production by personalization, customization and relative simplicity of 3D-models creation. 3D models ability to demonstrate heart anatomy is of use in cardiac surgery, primarily during the educational process and preoperative planning and, less common, for implantable devices testing and hemodynamic modeling. Although the role of 3D models in clinical practice is not currently defined, 3D printing mass application can provide important advantages to solve a number of diagnostic and therapeutic issues. The article presents the revue of scientific publications describing the use of physical three-dimensional heart models in cardiac surgery.

Percutaneous mitral valve repair in adults with congenital heart disease: Report of the first case-series.

Systemic atrioventricular valve regurgitation (AVVR) is frequently encountered in adults with congenital heart disease (CHD). Surgical intervention is the mainstay of therapy, but in a specific high-risk subset, percutaneous valve repair might offer a lower-risk alternative. Three patients with complex CHD and severe symptomatic AVVR underwent percutaneous mitral valve repair at a single center. All were deemed to be high-risk for surgery by a multidisciplinary CHD team and provided informed consent for the compassionate use of the MitraClip (Abbott, Santa Clara, CA). Three-dimensional heart models were generated for the procedure, which was performed by an adult CHD cardiologist (who provided imaging support) and an interventional cardiologist with expertise in CHD and percutaneous mitral valve repair. The first case was a 39 year-old-woman with [S,L,D] dextrocardia, double outlet right ventricle, mild tricuspid hypoplasia, and a secundum atrial septal defect, who was palliated at age 35 with a right bidirectional Glenn and later developed severe, symptomatic mitral regurgitation, and underwent placement of one MitraClip XTR device. Two patients with L-loop transposition of the great arteries each successfully underwent placement of two MitraClip XTR devices; one patient had a single-leaflet detachment of one of the clips with no change in regurgitation or clip position on follow-up. All patients had significant reduction of AVVR and improvement in NYHA functional class. Percutaneous atrioventricular valve repair in adults with CHD is feasible with the MitraClip but requires significant preprocedural planning and a multidisciplinary team that combines CHD and interventional therapeutic expertise.

Three-Dimensional Printing, Virtual Reality and Mixed Reality for Pulmonary Atresia: Early Surgical Outcomes Evaluation

Single-stage unifocalisation for pulmonary atresia (PA) with ventricular septal defect (VSD) and major aortopulmonary collateral arteries (MAPCA) requires a high degree of three-dimensional (3D) anatomical imagination. A previous study has reported the application of a 3D-printed heart model with virtual reality (VR) or mixed reality (MR). However, few studies have evaluated the surgical outcomes of the 3D model with VR or MR in PA/VSD patients. Three-dimensional (3D) heart models of five selected PA/VSD patients were derived from traditional imageology of their hearts. Using VR glasses, the 3D models were also visualised in the operating room. Both the 3D-printed heart models and preoperative evaluation by VR were used in the five selected patients for surgical simulation and better anatomical understanding. Mixed reality holograms were used as perioperative assistive tools. Surgical outcomes were assessed, including in-hospital and early follow-up clinical data. The use of these three new technologies had favourable feedback from the surgeons on intraoperative judgment. There were no in-hospital or early deaths. No reintervention was required until the last follow-up. Three (3) patients developed postoperative complications: one had right bundle branch block and ST-segment change, one had chest drainage >7 days (>40 mL/day) and one had pneumonia. The preoperative application of a 3D-printed heart model with VR or MR helped in aligning the surgical field. These technologies improved the understanding of complicated cardiac anatomy and achieved acceptable surgical outcomes as guiding surgical planning.

Speckle tracking echocardiography in hypokinetic non-dilated cardiomyopathy: comparison with dilated cardiomyopathy.

AimsHypokinetic non‐dilated cardiomyopathy (HNDC), which is determined by impaired left ventricular (LV) systolic function despite normal LV size, has been categorized as a subgroup of dilated cardiomyopathy (DCM) spectrum. Lack of data regarding advanced echocardiographic data in this population motivated us to design the present study in order to assess LV myocardial deformation properties of HNDC patients against the ones with dilated left ventricle.Methods and resultsThirty‐one HNDC patients and 23 DCM patients were enrolled in the study consecutively. Myocardial deformation parameters including global longitudinal strain, global circumferential strain, LV basal and apical rotation, LV twist, and LV mechanical dispersion were obtained with the use of two‐dimensional speckle tracking‐based methods in all patients. Left cardiac chamber volume was also measured using three‐dimensional HeartModel application. Patients with enlarged left ventricle tend to have lower LV ejection fraction. Comparing with HNDC group, DCM patients showed worse global circumferential strain (coefficient ± standard error 3.59 ± 0.94, P < 0.001) and LV mechanical dispersion (coefficient ± standard error 16.46 ± 7.09, P = 0.02) after regression analysis, while neither the global longitudinal strain nor the LV twist was not significantly different between two study population.ConclusionsLeft ventricular enlargement has a substantial effect on the circumferential strain and mechanical dispersion more than other deformation parameters that may play a role in the assumed poor prognosis of heart failure patients with dilated left ventricle.

Personalized Perioperative Multi-scale, Multi-physics Heart Simulation of Double Outlet Right Ventricle.

For treatment of complex congenital heart disease, computer simulation using a three-dimensional heart model may help to improve outcomes by enabling detailed preoperative evaluations. However, no highly integrated model that accurately reproduces a patient's pathophysiology, which is required for this simulation has been reported. We modelled a case of complex congenital heart disease, double outlet right ventricle with ventricular septal defect and atrial septal defect. From preoperative computed tomography images, finite element meshes of the heart and torso were created, and cell model of cardiac electrophysiology and sarcomere dynamics was implemented. The parameter values of the heart model were adjusted to reproduce the patient's electrocardiogram and haemodynamics recorded preoperatively. Two options of in silico surgery were performed using this heart model, and the resulting changes in performance were examined. Preoperative and postoperative simulations showed good agreement with clinical records including haemodynamics and measured oxyhaemoglobin saturations. The use of a detailed sarcomere model also enabled comparison of energetic efficiency between the two surgical options. A novel in silico model of congenital heart disease that integrates molecular models of cardiac function successfully reproduces the observed pathophysiology. The simulation of postoperative state by in silico surgeries can help guide clinical decision-making.

Research progress of 3D printing technology in congenital heart disease

3D printing technology has achieved good results in the diagnosis and guidance of congenital heart disease(CHD). Computed tomography (CT) and magnetic resonance imaging (MRI) are used as data sources to establish a three-dimensional model of the heart, which has been used clinically.The use of non-invasive techniques such as three-dimensional ultrasound to obtain data sources for 3D printing models can bring about changes in the diagnosis and treatment of CHD.This paper reviews the research progress of 3D printing technology in CHD with CT, MRI and 3D ultrasound. Key words: Congenital heart disease; 3D printing technology; Cardiac stereoscopic model; Three-dimensional ultrasound

Quantification of Biventricular Strains in Heart Failure With Preserved Ejection Fraction Patient Using Hyperelastic Warping Method.

Heart failure (HF) imposes a major global health care burden on society and suffering on the individual. About 50% of HF patients have preserved ejection fraction (HFpEF). More intricate and comprehensive measurement-focused imaging of multiple strain components may aid in the diagnosis and elucidation of this disease. Here, we describe the development of a semi-automated hyperelastic warping method for rapid comprehensive assessment of biventricular circumferential, longitudinal, and radial strains that is physiological meaningful and reproducible. We recruited and performed cardiac magnetic resonance (CMR) imaging on 30 subjects [10 HFpEF, 10 HF with reduced ejection fraction patients (HFrEF) and 10 healthy controls]. In each subject, a three-dimensional heart model including left ventricle (LV), right ventricle (RV), and septum was reconstructed from CMR images. The hyperelastic warping method was used to reference the segmented model with the target images and biventricular circumferential, longitudinal, and radial strain–time curves were obtained. The peak systolic strains are then measured and analyzed in this study. Intra- and inter-observer reproducibility of the biventricular peak systolic strains was excellent with all ICCs > 0.92. LV peak systolic circumferential, longitudinal, and radial strain, respectively, exhibited a progressive decrease in magnitude from healthy control→HFpEF→HFrEF: control (-15.5 ± 1.90, -15.6 ± 2.06, 41.4 ± 12.2%); HFpEF (-9.37 ± 3.23, -11.3 ± 1.76, 22.8 ± 13.1%); HFrEF (-4.75 ± 2.74, -7.55 ± 1.75, 10.8 ± 4.61%). A similar progressive decrease in magnitude was observed for RV peak systolic circumferential, longitudinal and radial strain: control (-9.91 ± 2.25, -14.5 ± 2.63, 26.8 ± 7.16%); HFpEF (-7.38 ± 3.17, -12.0 ± 2.45, 21.5 ± 10.0%); HFrEF (-5.92 ± 3.13, -8.63 ± 2.79, 15.2 ± 6.33%). Furthermore, septum peak systolic circumferential, longitudinal, and radial strain magnitude decreased gradually from healthy control to HFrEF: control (-7.11 ± 1.81, 16.3 ± 3.23, 18.5 ± 8.64%); HFpEF (-6.11 ± 3.98, -13.4 ± 3.02, 12.5 ± 6.38%); HFrEF (-1.42 ± 1.36, -8.99 ± 2.96, 3.35 ± 2.95%). The ROC analysis indicated LV peak systolic circumferential strain to be the most sensitive marker for differentiating HFpEF from healthy controls. Our results suggest that the hyperelastic warping method with the CMR-derived strains may reveal subtle impairment in HF biventricular mechanics, in particular despite a “normal” ventricular ejection fraction in HFpEF.

A new approach of three-dimensional guidance in paediatric cath lab: segmented and tessellated heart models for cardiovascular interventions in CHD.

Optimal imaging is essential for catheter-based interventions in CHD. The three-dimensional models in volume-rendering technique currently in use are not standardised. This paper investigates the feasibility and impact of novel three-dimensional guidance with segmented and tessellated three-dimensional heart models in catheterisation of CHD. In addition, a nearly radiation-free two- to three-dimensional registration and a biplane overlay were used.Methods and resultsWe analysed 60 consecutive cases in which segmented tessellated three-dimensional heart models were merged with live fluoroscopy images and aligned using the tracheal bifurcation as a fiducial mark. The models were generated from previous MRI or CT by dedicated medical software. We chose the stereo-lithography format, as this promises advantage over volume-rendering-technique models regarding visualisation. Prospects, potential benefits, and accuracy of the two- to three-dimensional registration were rated separately by two paediatric interventionalists on a five-point Likert scale. Fluoroscopy time, radiation dose, and contrast dye consumption were evaluated. Over a 10-month study period, two- to three-dimensional image fusion was applied to 60 out of 354 cases. Of the 60 catheterisations, 73.3% were performed in the context of interventions. The accuracy of two- to three-dimensional registration was sufficient in all cases. Three-dimensional guidance was rated superior to conventional biplane imaging in all 60 cases. We registered significantly smaller amounts of used contrast dye (p<0.01), lower levels of radiation dose (p<0.02), and less fluoroscopy time (p<0.01) during interventions concerning the aortic arch compared with a control group. Two- to three-dimensional image fusion can be applied successfully in most catheter-based interventions of CHD. Meshes in stereo-lithography format are accurate and base for standardised and reproducible three-dimensional models.

Percutaneous Transcatheter Mitral Valve Replacement: Patient-specific Three-dimensional Computer-based Heart Model and Prototyping

Mitral regurgitation is the most prevalent valvular heart disease worldwide. Despite the widespread availability of curative surgical intervention, a considerable proportion of patients with severe mitral regurgitation are not referred for treatment, largely due to the presence of left ventricular dysfunction, advanced age, and comorbid illnesses. Transcatheter mitral valve replacement is a promising therapeutic alternative to traditional surgical valve replacement. The complex anatomical and pathophysiological nature of the mitral valvular complex, however, presents significant challenges to the successful design and implementation of novel transcatheter mitral replacement devices. Patient-specific 3-dimensional computer-based models enable accurate assessment of the mitral valve anatomy and preprocedural simulations for transcatheter therapies. Such information may help refine the design features of novel transcatheter mitral devices and enhance procedural planning. Herein, we describe a novel medical image-based processing tool that facilitates accurate, noninvasive assessment of the mitral valvular complex, by creating precise three-dimensional heart models. The 3-dimensional computer reconstructions are then converted to a physical model using 3-dimensional printing technology, thereby enabling patient-specific assessment of the interaction between device and patient. It may provide new opportunities for a better understanding of the mitral anatomy-pathophysiology-device interaction, which is of critical importance for the advancement of transcatheter mitral valve replacement.

Sustitución percutánea transcatéter de la válvula mitral: modelo cardiaco y diseño tridimensional mediante ordenador de prototipo específico para cada paciente

Mitral regurgitation is the most prevalent valvular heart disease worldwide. Despite the widespread availability of curative surgical intervention, a considerable proportion of patients with severe mitral regurgitation are not referred for treatment, largely due to the presence of left ventricular dysfunction, advanced age, and comorbid illnesses. Transcatheter mitral valve replacement is a promising therapeutic alternative to traditional surgical valve replacement. The complex anatomical and pathophysiological nature of the mitral valvular complex, however, presents significant challenges to the successful design and implementation of novel transcatheter mitral replacement devices. Patient-specific 3-dimensional computer-based models enable accurate assessment of the mitral valve anatomy and preprocedural simulations for transcatheter therapies. Such information may help refine the design features of novel transcatheter mitral devices and enhance procedural planning. Herein, we describe a novel medical image-based processing tool that facilitates accurate, noninvasive assessment of the mitral valvular complex, by creating precise three-dimensional heart models. The 3-dimensional computer reconstructions are then converted to a physical model using 3-dimensional printing technology, thereby enabling patient-specific assessment of the interaction between device and patient. It may provide new opportunities for a better understanding of the mitral anatomy-pathophysiology-device interaction, which is of critical importance for the advancement of transcatheter mitral valve replacement.Full English text available from:www.revespcardiol.org/en

局所多点電極アレイを用いた心外膜広域電気生理マッピング手法の提案

Arrhythmia surgery is performed to treat serious arrhythmia such as atrial fibrillation and ventricular tachycardia unable to be treated by catheter ablation. Mapping devices are needed to find electrical abnormal regions. Open heart surgery is invasive for patient's body. Recently, endoscopic arrhythmia surgery is reported as minimally invasive surgery. Existing mapping device can be used only in open heart surgery. There is no mapping device available under endoscopic surgery. We developed a local multi-electrode array to measure epicardial electrophysiological data under endoscopic surgery. However, it can obtain the propagation only in the local area not in the global area. We recorded single beat electrical activities at different time and different location and mapped them onto a three-dimensional heart model. The phase shifts in local potentials were synchronized in reference to the ECG. Location errors due to heart beat and deformation were corrected by a propagation registration method assuming the continuous propagation in the heart. Both registration errors and the distribution of propagation decreased in simulation data. Continuous propagation was obtained in experimental data. Global propagation of excitation can be obtained from local isopotential maps.

Investigation of spatial action potential distributions in myocardium using three-dimensional biventricular heart model

Computer simulation of cardiac electrical activity is conducted using a three-dimensional biventricular heart model incorporating action potential formulations. A heterogeneous continuous spatial distribution of action potentials based on different dependences of maximal slow delayed rectifier current conductance is proposed and implemented to study electrocardiographic T-waves. It is demonstrated that the proposed distribution is reasonable and reproduces realistic electrocardiographic waveforms.

Modeling and Representation of Human Hearts for Volumetric Measurement

This paper investigates automatic construction of a three-dimensional heart model from a set of medical images, represents it in a deformable shape, and uses it to perform volumetric measurements. This not only significantly improves its reliability and accuracy but also makes it possible to derive valuable novel information, like various assessment and dynamic volumetric measurements. The method is based on a flexible model trained from hundreds of patient image sets by a genetic algorithm, which takes advantage of complete segmentation of the heart shape to form a geometrical heart model. For an image set of a new patient, an interpretation scheme is used to obtain its shape and evaluate some important parameters. Apart from automatic evaluation of traditional heart functions, some new information of cardiovascular diseases may be recognized from the volumetric analysis.