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Identifying the detailed anatomies of the coronary microvasculature remains an area of research; one needs to develop methods for non-destructive, high-resolution, three-dimensional imaging of these vessels for computational modeling. Currently employed Micro-Computed Tomography (Micro-CT) protocols for vasa vasorum analyses require organ dissection and, in most cases, non-clearable contrast agents. Here, we describe a method developed for a non-destructive, economical means to achieve high-resolution images of the human coronary microvasculature without organ dissection. Formalin-fixed human hearts were cannulated using venogram balloon catheters, which were then fixed into the specimen's aortic root. The canulated hearts, protected by a polyethylene bag, were placed in radiolucent containers filled with insulating polyurethane foam to reduce movement. For vasculature staining, iodine potassium iodide (IKI, Lugol's solution; 6.3% Potassium Iodide, 4.1% Iodide) was injected. Contrast distributions were monitored using a North Star Imaging X3000 micro-CT scanner with low-radiation settings, followed by high-radiation scanning (3600 rad, 60 kV, 900 mA) for the final high-resolution imaging. We successfully imaged four intact human hearts presenting with chronic total coronary occlusions of the right coronary artery. This imaging enabled detailed analyses of the vasa vasorum surrounding stenosed and occluded segments. After imaging, the hearts were cleared of iodine and excess polyurethane foam and returned to their initial formalin-fixed state for indefinite storage. Conclusions: the described methodologies allow for the non-destructive, high-resolution micro-CT imaging of coronary microvasculature in intact human hearts, paving the way for detailed computational 3D microvascular reconstructions with a macrovascular context.
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BACKGROUND: Assessment of origin of ventricular tachycardias (VTs) arising from epicardial vs endocardial sites are largely challenged by the available criteria and etiology of cardiomyopathy. Current electrocardiographic (ECG) criteria based on 12-lead ECG have varying sensitivity and specificity based on site of origin and etiology of cardiomyopathy. OBJECTIVES: This study sought to test the hypothesis that epicardial VT has a slower initial rate of depolarization than endocardial VT. METHODS: We developed a method that takes advantage of the fact that electrical conduction is faster through the cardiac conduction system than the myocardium, and that the conduction system is primarily an endocardial structure. The technique calculated the rate of change in the initial VT depolarization from a signal-averaged 12-lead ECG. We hypothesized that the rate of change of depolarization in endocardial VT would be faster than epicardial. We assessed by applying this technique among 26 patients with VT in nonischemic cardiomyopathy patients. RESULTS: When comparing patients with VTs ablated using epicardial and endocardial approaches, the rate of change of depolarization was found to be significantly slower in epicardial (6.3 ± 3.1 mV/s vs 11.4 ± 3.7 mV/s; P < 0.05). Statistical significance was found when averaging all 12 ECG leads and the limb leads, but not the precordial leads. Follow up analysis by calculation of a receiver-operating characteristic curve demonstrated that this analysis provides a strong prediction if a VT is epicardial in origin (AUC range 0.72-0.88). Slower rate of change of depolarization had high sensitivity and specificity for prediction of epicardial VT. CONCLUSIONS: This study demonstrates that depolarization rate analysis is a potential technique to predict if a VT is epicardial in nature.
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Eletrocardiografia , Endocárdio , Pericárdio , Taquicardia Ventricular , Humanos , Taquicardia Ventricular/fisiopatologia , Taquicardia Ventricular/diagnóstico , Masculino , Feminino , Pessoa de Meia-Idade , Endocárdio/fisiopatologia , Pericárdio/fisiopatologia , Idoso , Sistema de Condução Cardíaco/fisiopatologia , Cardiomiopatias/fisiopatologia , Adulto , Ablação por Cateter , Sensibilidade e EspecificidadeRESUMO
OBJECTIVE: Long-term assessments of lower leg muscle forces in ambulant patients with distal myopathies. METHODS AND MATERIALS: Over a five-year period, we measured involuntary, nerve-stimulated, isometric torques of the ankle dorsiflexors in a group of ambulant patients with myopathies and compared results with voluntary Manual Muscle Tests (MMT). RESULTS: From ten recruited patients, five could finish the five-year protocol. Twenty-seven force measurements sessions (one per year; 1,5 hours duration each) were performed. These patients exhibited low, stable torques or increased minimally (0.2 Newtonmeter, versus 0.1 Nm, ns; 0.7 vs. 1.0, ns; 3.4 vs. 3.5, ns; 0.2 vs. 0.1, ns; 0.8 vs. 1.5, P 0.0004 initial values vs. 5-year values, [norm: 3.9-5.7 Nm]). A 6th patient, eliciting low torque values (0.1 Nm) early passed away. Contraction times inversely correlated with MMT. MMT provided similar overall force abilities. CONCLUSIONS: Long-term monitoring of lower leg muscle forces in ambulant patients is limited by the patient's health status. In a small group of patients, stimulated lower leg forces did not worsen over many years relative to their diagnosed myopathies. Tracking involuntary forces, could be a useful monitoring providing phenotypic information, in addition to MMT. Future devices should be small and be simply self-applying, designed for subjects' domestic use and web-based data transfer. CLINICALTRIALS: gov NCT00735384.
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Músculo Esquelético , Torque , Humanos , Masculino , Músculo Esquelético/fisiologia , Músculo Esquelético/fisiopatologia , Pessoa de Meia-Idade , Feminino , Adulto , Doenças Musculares/fisiopatologia , Seguimentos , Perna (Membro)/fisiopatologia , Perna (Membro)/fisiologia , Contração Isométrica/fisiologia , Força Muscular/fisiologia , Idoso , Contração Muscular/fisiologiaRESUMO
Epicardial interventions have forged new frontiers in cardiac ablation and device therapies. Healthy human hearts typically present with significant adipose tissue layers superficial to the ventricular myocardium and may hinder success or increase the complexities of epicardial interventions. We quantitatively evaluated the distribution of epicardial adipose tissue on the surface of human hearts and provided high-fidelity 3-dimensional reconstructions of these epicardial adipose tissue layers. The regional thickness of adipose tissues was analyzed at 51 anatomical reference points surrounding both ventricles and compared to specific patient demographics. Adipose deposits on the human hearts displayed characteristic patterns, with the thickest accumulations along the interventricular septa (anterior, 9.01 ± 0.50 mm; posterior, 6.78 ± 0.50 mm) and the right ventricular margin (7.44 ± 0.57 mm). We provide one of the most complete characterizations of human epicardial adipose location and relative layer thickness. These results are considered fundamental for an underlying anatomic understanding when performing procedures within the pericardial space.
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Tecido Adiposo , Ventrículos do Coração , Imageamento Tridimensional , Pericárdio , Humanos , Pericárdio/anatomia & histologia , Tecido Adiposo/diagnóstico por imagem , Masculino , Feminino , Pessoa de Meia-Idade , Ventrículos do Coração/diagnóstico por imagem , Idoso , Adiposidade , Adulto , Valor Preditivo dos TestesRESUMO
Electroporation is used in medicine for drug and gene delivery, and as a nonthermal ablation method in tumor treatment and cardiac ablation. Electroporation involves delivering high-voltage electric pulses to target tissue; however, this can cause effects beyond the intended target tissue like nerve stimulation, muscle contractions and pain, requiring use of sedatives or anesthetics. It was previously shown that adjusting pulse parameters may mitigate some of these effects, but not how these adjustments would affect electroporation's efficacy. We investigated the effect of varying pulse parameters such as interphase and interpulse delay while keeping the duration and number of pulses constant on nerve stimulation, muscle contraction and assessing pain and electroporation efficacy, conducting experiments on human volunteers, tissue samples and cell lines in vitro. Our results show that using specific pulse parameters, particularly short high-frequency biphasic pulses with short interphase and long interpulse delays, reduces muscle contractions and pain sensations in healthy individuals. Higher stimulation thresholds were also observed in experiments on isolated swine phrenic nerves and human esophagus tissues. However, changes in the interphase and interpulse delays did not affect the cell permeability and survival, suggesting that modifying the pulse parameters could minimize adverse effects while preserving therapeutic goals in electroporation.
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Background and Aims: Modern health care faces a plethora of challenges including the delivery of quality and cost-efficient care. Physicians are first-hand observers of clinical problems but may lack the requisite training and education to develop innovations that improve patient care. Few medical education programs address innovation, leadership, and transdisciplinary collaboration despite being highlighted by national medical and education organizations including the American Medical Association. The University of Minnesota has implemented the Augustine program over the last 10-years to produce physicians that are leaders in medical innovation. Methods: As a novel joint engineering-medical school curriculum to educate medical students, residents, and fellows, the Augustine program incorporates engineering coursework, biomedical research, and a multidisciplinary design and business development experience to produce physicians capable of designing and marketing "disruptive technologies." The Augustine program takes 1-year to complete in addition to the 4-year medical education and provides a Master of Biomedical Engineering upon completion. Results: Augustine program graduates (n = 6) have reported significant contributions related to the joint engineering-medical education including peer-reviewed publications (Median: 13), deployable assets (Median: 2), and intellectual property (Median: 1). Most surveyed graduates (n = 5, 83%) continue to be active contributors to medical innovation and all (n = 6, 100%) utilize their transdisciplinary education to improve patient care. Conclusion: Augustine program graduates impact the entire spectrum of innovation and continue to improve patient care. The program will seek to emphasize the inclusion of physician residents and fellows with position expansion. The addition of a multi-week medical innovation clerkship will provide a more focused experience for students unable to dedicate an entire year to a transdisciplinary experience.
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Artificial intelligence, computational simulations, and extended reality, among other 21st century computational technologies, are changing the health care system. To collectively highlight the most recent advances and benefits of artificial intelligence, computational simulations, and extended reality in cardiovascular therapies, we coined the abbreviation AISER. The review particularly focuses on the following applications of AISER: 1) preprocedural planning and clinical decision making; 2) virtual clinical trials, and cardiovascular device research, development, and regulatory approval; and 3) education and training of interventional health care professionals and medical technology innovators. We also discuss the obstacles and constraints associated with the application of AISER technologies, as well as the proposed solutions. Interventional health care professionals, computer scientists, biomedical engineers, experts in bioinformatics and visualization, the device industry, ethics committees, and regulatory agencies are expected to streamline the use of AISER technologies in cardiovascular interventions and medicine in general.
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Inteligência Artificial , Humanos , Resultado do TratamentoRESUMO
Developing an accurate and detailed 3-dimensional (3D) mental model of cardiac anatomy is critical for electrophysiology (EP) trainees. Due to its immersive nature, virtual reality (VR) may provide a better learning environment than traditional teaching methods for assimilating 3D cardiac anatomy. The purpose of this pilot study was to evaluate the technical feasibility of an interactive, remote VR-based method for teaching cardiac anatomy to novice EP trainees. We created a shared, remote VR environment that allows the shared viewing of high-resolution 3D cardiac models. Eighteen trainees accepted for pediatric and adult EP fellowships were recruited. We performed a cohort study comparing the traditional teaching methods with the VR learning environment. Participants completed a demographic questionnaire and a satisfaction survey. The adult EP trainees were given a multiple-choice pre- and post-test exam to assess their anatomical knowledge. Both the adult and pediatric EP trainee cohorts rated the VR experience positively and preferred the VR environment to the more traditional teaching method. All the participants expressed interest in incorporating the VR learning environment into the EP fellowship curriculum. The usability of the system was relatively low, with approximately one-third of participants rating the system as hard to use. The impact of the VR session on exam performance was mixed among the adult cohort. We demonstrated the feasibility of gathering geographically dispersed EP fellows in training with a shared VR-based environment to teach cardiac anatomy. Although we were not able to demonstrate a learning benefit over the traditional lecture format in the adult cohort, the training environment was favorably received by all the participants.
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Introduction: Pulsed field ablation is an emerging modality for catheter-based cardiac ablation. The main mechanism of action is irreversible electroporation (IRE), a threshold-based phenomenon in which cells die after exposure to intense pulsed electric fields. Lethal electric field threshold for IRE is a tissue property that determines treatment feasibility and enables the development of new devices and therapeutic applications, but it is greatly dependent on the number of pulses and their duration. Methods: In the study, lesions were generated by applying IRE in porcine and human left ventricles using a pair of parallel needle electrodes at different voltages (500-1500 V) and two different pulse waveforms: a proprietary biphasic waveform (Medtronic) and monophasic 48 × 100 µs pulses. The lethal electric field threshold, anisotropy ratio, and conductivity increase by electroporation were determined by numerical modeling, comparing the model outputs with segmented lesion images. Results: The median threshold was 535 V/cm in porcine ((N = 51 lesions in n = 6 hearts) and 416 V/cm in the human donor hearts ((N = 21 lesions in n = 3 hearts) for the biphasic waveform. The median threshold value was 368 V/cm in porcine hearts ((N = 35 lesions in n = 9 hearts) cm for 48 × 100 µs pulses. Discussion: The values obtained are compared with an extensive literature review of published lethal electric field thresholds in other tissues and were found to be lower than most other tissues, except for skeletal muscle. These findings, albeit preliminary, from a limited number of hearts suggest that treatments in humans with parameters optimized in pigs should result in equal or greater lesions.
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INTRODUCTION: Echocardiography is essential for diagnosing and assessing the severity of perioperative structural and functional heart disease. Yet, educational opportunities to better understand echocardiography-based cardiac anatomy remain limited by the two-dimensional display, lack of anatomic details, variability of heart models, and costs and global access of training. METHODS: We performed micro computed tomography of human heart specimens not suitable for orthotopic transplantation. We created high-resolution computational 3D models of different human hearts, sliced them in the different recommended American Society of Echocardiography views, and 3D printed them using different materials. RESULTS: We scanned, 3D modeled, and 3D printed a variety of human hearts both healthy and diseased. We have made the models available in the cardiac operating rooms and routinely use them for teaching anesthesia residents and cardiothoracic anesthesia fellows about basic and advanced echocardiographic views, cardiopulmonary bypass cannulation strategies, and valvular pathology and planned interventions. CONCLUSION: We have generated a library of 3D printed hearts to display the recommended echocardiographic views as a unique educational tool designed to safely accelerate the understanding of absolute and relative human cardiac anatomy and pathology, especially related to gaining advanced appreciation of clinically employed perioperative echocardiography.
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Cardiopatias , Coração , Humanos , Microtomografia por Raio-X , Coração/diagnóstico por imagem , Ecocardiografia , Modelos AnatômicosRESUMO
While mitral valve (MV) repair remains the preferred clinical option for mitral regurgitation (MR) treatment, long-term outcomes remain suboptimal and difficult to predict. Furthermore, pre-operative optimization is complicated by the heterogeneity of MR presentations and the multiplicity of potential repair configurations. In the present work, we established a patient-specific MV computational pipeline based strictly on standard-of-care pre-operative imaging data to quantitatively predict the post-repair MV functional state. First, we established human mitral valve chordae tendinae (MVCT) geometric characteristics obtained from five CT-imaged excised human hearts. From these data, we developed a finite-element model of the full patient-specific MV apparatus that included MVCT papillary muscle origins obtained from both the in vitro study and the pre-operative three-dimensional echocardiography images. To functionally tune the patient-specific MV mechanical behavior, we simulated pre-operative MV closure and iteratively updated the leaflet and MVCT prestrains to minimize the mismatch between the simulated and target end-systolic geometries. Using the resultant fully calibrated MV model, we simulated undersized ring annuloplasty (URA) by defining the annular geometry directly from the ring geometry. In three human cases, the postoperative geometries were predicted to 1 mm of the target, and the MV leaflet strain fields demonstrated close agreement with noninvasive strain estimation technique targets. Interestingly, our model predicted increased posterior leaflet tethering after URA in two recurrent patients, which is the likely driver of long-term MV repair failure. In summary, the present pipeline was able to predict postoperative outcomes from pre-operative clinical data alone. This approach can thus lay the foundation for optimal tailored surgical planning for more durable repair, as well as development of mitral valve digital twins.
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Doenças das Valvas Cardíacas , Insuficiência da Valva Mitral , Humanos , Valva Mitral/diagnóstico por imagem , Valva Mitral/cirurgia , Insuficiência da Valva Mitral/diagnóstico por imagem , Insuficiência da Valva Mitral/cirurgia , Músculos Papilares , Cordas TendinosasRESUMO
BACKGROUND: In patients with complex coronary bifurcation lesions undergoing percutaneous coronary intervention (PCI), various 2-stent techniques might be utilised. The Visible Heart Laboratories (VHL) offer an experimental environment where PCI results can be assessed by multimodality imaging. AIMS: We aimed to assess the post-PCI stent configuration achieved by 2-stent techniques in the VHL and to evaluate the procedural factors associated with suboptimal results. METHODS: Bifurcation PCI with 2-stent techniques, performed by expert operators in the VHL on explanted beating swine hearts, was studied. The adopted bifurcation PCI strategy and the specific procedural steps applied in each procedure were classified according to Main, Across, Distal, Side (MADS)-2 and to their adherence to the European Bifurcation Club (EBC) recommendations. Microcomputed tomography (micro-CT) was used to assess the post-PCI stent configuration. The primary endpoint was "suboptimal stent implantation", defined as a composite of stent underexpansion (<90%), side branch ostial area stenosis >50% and the gap between stents. RESULTS: A total of 82 PCI with bifurcation stenting were assessed, comprised of 29 crush, 25 culotte, 28 T/T and small protrusion (TAP) techniques. Suboptimal stent implantation was observed in as many as 53.7% of the cases, regardless of baseline anatomy or the stenting strategy. However, less frequent use of the proximal optimisation technique (POT; p=0.015) and kissing balloon inflations (KBI; p=0.027) and no adherence to EBC recommendations (p=0.004, p multivariate=0.006) were significantly associated with the primary endpoint. CONCLUSIONS: Commonly practised bifurcation 2-stent techniques may result in imperfect stent configurations. More frequent use of POT/KBI and adherence to expert recommendations might reduce the occurrence of post-PCI suboptimal stent configurations.
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Doença da Artéria Coronariana , Intervenção Coronária Percutânea , Animais , Suínos , Intervenção Coronária Percutânea/métodos , Microtomografia por Raio-X , Resultado do Tratamento , Stents , Constrição Patológica , Angiografia Coronária/métodos , Doença da Artéria Coronariana/cirurgiaRESUMO
OBJECTIVE: The goal of our study was to determine the importance of electric field orientation in an anisotropic muscle tissue for the extent of irreversible electroporation damage by means of an experimentally validated mathematical model. METHODS: Electrical pulses were delivered to porcine skeletal muscle in vivo by inserting needle electrodes so that the electric field was applied in direction either parallel or perpendicular to the direction of the muscle fibres. Triphenyl tetrazolium chloride staining was used to determine the shape of the lesions. Next, we used a single cell model to determine the cell-level conductivity during electroporation, and then generalised the calculated conductivity changes to the bulk tissue. Finally, we compared the experimental lesions with the calculated field strength distributions using the Sørensen-Dice similarity coefficient to find the contours of the electric field strength threshold beyond which irreversible damage is thought to occur. RESULTS: Lesions in the parallel group were consistently smaller and narrower than lesions in the perpendicular group. The determined irreversible threshold of electroporation for the selected pulse protocol was 193.4 V/cm with a standard deviation of 42.1 V/cm, and was not dependent on field orientation. CONCLUSION: Muscle anisotropy is of significant importance when considering electric field distribution in electroporation applications. SIGNIFICANCE: The paper presents an important advancement in building up from the current understanding of single cell electroporation to an in silico multiscale model of bulk muscle tissue. The model accounts for anisotropic electrical conductivity and has been validated through experiments in vivo.
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Eletroporação , Músculo Esquelético , Animais , Suínos , Eletroporação/métodos , Terapia com Eletroporação , Eletricidade , Simulação por Computador , Condutividade ElétricaRESUMO
BACKGROUND: Percutaneous coronary interventions (PCIs) within left main coronary arteries are high-risk procedures that require optimization of interactions between stent(s) and diseased vessels. Optical Coherence Tomography (OCT) is a widely accepted tool that enhances physicians' ability to assess proper stent appositions during clinical procedures. The primary aim of this study was to develop complementary post-procedure imaging methodologies to better assess and interpret outcomes of left main PCI procedures, utilizing both reanimated and perfusion-fixed human hearts. METHODS: PCIs were performed while obtaining OCT scans within the left main anatomies of six human hearts. Subsequently, each heart was scanned with a micro-CT scanner with optimized parameters to achieve resolutions up to 20 µm. Scans were reconstructed and imported into a DICOM segmentation software to generate computational models of implanted stents and associated coronary vessels. 2D images from OCT that were obtained during PCIs were compared to the 3D models generated from micro-CT reconstructions. In addition, the 3D models were utilized to create virtual reality scenes and enlarged 3D prints for development of "mixed reality" tools relative to bifurcation stenting within human left main coronary arteries. RESULTS: We developed reproducible methodologies for post-implant analyses of coronary artery stenting procedures. In addition, we generated high-resolution 3D computational models, with ~ 20-micron resolutions, of PCIs performed within reanimated and perfusion-fixed heart specimens. CONCLUSIONS: Generated computational models of left main PCIs performed in isolated human hearts can be used to obtain detailed measurements that provide further clinical insights on procedural outcomes. The 3D models from these procedures are useful for generating virtual reality scenes and 3D prints for physician training and education.
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Doença da Artéria Coronariana , Intervenção Coronária Percutânea , Humanos , Vasos Coronários/diagnóstico por imagem , Vasos Coronários/cirurgia , Intervenção Coronária Percutânea/métodos , Angiografia Coronária/métodos , Microtomografia por Raio-X , Resultado do Tratamento , Stents , Perfusão , Tomografia de Coerência Óptica/métodosRESUMO
Preclinical research remains the essential platform in the development and optimization of medical therapies and advancements in translational medicines. However, specifically to animal research, federal laws, and institutional policies require investigators to apply the principles of the 3R's (replacement, reduction, and refinement). The concept of benchtop models utilizing isolated organs, in which multiple variables can be controlled to recreate human function, has been innovative advancements in preclinical research models that adhere to these principles. More specifically, isolated perfused kidney (IPK) models have been invaluable preclinical tools that have led to numerous advancements over the decades, including understanding renal physiology, pharmacologic therapies, and improvements in renal transplantation. However, pre-existing IPK models are not without their own limitations, leaving areas for improvement. An isolated perfused kidney apparatus was designed to best recreate human use conditions as a preclinical tool. Porcine renal blocks were chosen over the more commonly used rodent models, due to their greater similarities to human anatomies. Sixteen porcine kidney pairs obtained en bloc were extracted and placed onto an apparatus where aortic flows, pressures, and overall systemic temperatures were controlled. Organ viability was assessed in 10 renal blocks (n = 8 fresh and n = 2 previously frozen specimens) via both urinary flows and compositions at timepoints up to 180 min. Multimodality imaging, which included fluoroscopy, ultrasound, optical coherence tomography (OCT), and video scopes, was also employed to capture internal and external images to determine renal artery orientations and dimensions. Anatomical measurements and viability assessments of porcine renal blocks were successfully achieved in our perfusion model. Renal main artery diameters averaged smaller in our sample size than in human anatomy while also having more superior takeoff angles. Yet, the average lengths of each main segment were comparable to human anatomy: 32.09 ± 7.97 mm and 42.23 ± 7.33 mm in the left and right renal main artery, respectively. Urine production and urine composition of the fresh renal blocks, when compared to the frozen blocks and baseline perfusate, showed kidney viabilities of up to 3 h via excretion and retention of various metabolites. In this paper, we described a protocol for an isolated perfused kidney apparatus using large mammalian renal blocks. We believe this protocol to be an improvement from similar pre-existing models in better representing human physiologic function while allowing for multimodal imaging. The resulting Visible Kidney™ preclinical model, which has shown viability after isolation and reperfusion, can be a fast and reliable tool for the development of medical devices while also reducing the unnecessary use of animals for research.
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Líquidos Corporais , Transplante de Rim , Humanos , Suínos , Animais , Rim , Diurese , Aorta , MamíferosRESUMO
Percutaneous coronary intervention can be a high-risk procedure that would benefit from optimizing device-tissue interactions between stents and coronary vessels. Using a perfusion-fixed human heart with coronary artery disease, we performed a percutaneous coronary intervention of the left main coronary artery bifurcation. This heart was perfused and multimodal imaging was utilized to view the procedure with direct visualization, fluoroscopy, and optical coherence tomography (OCT). We followed the European Bifurcation Club's guidelines to perform a single-stent bifurcation before transitioning to a two-stent Culotte technique. After each procedural step, the heart was removed from the perfusion apparatus and transferred to a micro-CT scanner to obtain unique scans. We conducted apposition analyses of the computational 3D models from micro-CT DICOM datasets, and compared them to the results from direct visualization and commercial OCT's Apposition Indicator software. Additional measurements of resulting coronary anatomic expansions were taken to determine the potential roles of each step in improving procedural outcomes. Micro-CT images show stent deformation during a percutaneous coronary intervention (provisional to Culotte bifurcation procedure) in an isolated diseased human heart.
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Doença da Artéria Coronariana , Intervenção Coronária Percutânea , Humanos , Vasos Coronários/diagnóstico por imagem , Vasos Coronários/cirurgia , Microtomografia por Raio-X , Resultado do Tratamento , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/cirurgia , Stents , Intervenção Coronária Percutânea/efeitos adversos , Perfusão , Imagem Multimodal , Angiografia Coronária/métodosRESUMO
BACKGROUND: Stepwise provisional stenting is the gold standard for percutaneous coronary intervention (PCI) on bifurcation lesions, but the optimal ballooning technique for eventual side branch treatment is not established. The objective of the present study was to compare the stent configuration obtained by 2 different side branch optimization techniques performed after main vessel (MV) stent implantation: proximal optimization technique+kissing balloon inflation+final proximal optimization technique (POT/KBI/POT [PKP]) versus proximal optimization technique+isolated side branch dilation+final proximal optimization technique (POT-side-POT [PSP]). METHODS: We realized a 1:1 prospective randomized trial comparing bifurcation PCI conducted (under angiographic and angioscopic visualization) with either PKP or PSP in reanimated swine hearts using commercially available drug-eluting stents. After PCI, the obtained stent configuration (expansion, eccentricity, apposition) was assessed by optical coherence tomography and micro-computed tomography dividing the stent in 4 segments. Primary study end point was minimum stent expansion at the distal MV segment. RESULTS: A total of 30 PCIs were successfully performed according to randomization obtaining overall good results (average minimum stent expansion >90% at optical coherence tomography and micro-computed tomography) with PSP or PKP. Minimum stent expansion at the distal MV segment was significantly higher with PKP as compared with PSP at optical coherence tomography (97.9±4.2% versus 91.0±7.7%; P=0.002) and micro-computed tomography (98.1±4.1% versus 91.3±7.9%; P=0.006). Other significant findings included higher stent eccentricity index at proximal MV with PSP, higher side branch scaffolding length and lower malapposition (at bifurcation core and distal MV) with PKP. CONCLUSIONS: This first prospective randomized trial in a unique non-atherosclerotic preclinical environment showed that bifurcation PCI conducted with PSP and PKP achieves different stent configurations. These findings might be useful in bifurcation PCI practice and call for further evaluations in clinical ground.
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Doença da Artéria Coronariana , Intervenção Coronária Percutânea , Animais , Angiografia Coronária/métodos , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/terapia , Intervenção Coronária Percutânea/efeitos adversos , Intervenção Coronária Percutânea/métodos , Estudos Prospectivos , Stents , Suínos , Resultado do Tratamento , Microtomografia por Raio-XRESUMO
The aim of this work was to analyze the influence of sex hormones and anatomical details (trabeculations and false tendons) on the electrophysiology of healthy human hearts. Additionally, sex- and anatomy-dependent effects of ventricular tachycardia (VT) inducibility are presented. To this end, four anatomically normal, human, biventricular geometries (two male, two female), with identifiable trabeculations, were obtained from high-resolution, ex-vivo MRI and represented by detailed and smoothed geometrical models (with and without the trabeculations). Additionally one model was augmented by a scar. The electrophysiology finite element model (FEM) simulations were carried out, using O'Hara-Rudy human myocyte model with sex phenotypes of Yang and Clancy. A systematic comparison between detailed vs smooth anatomies, male vs female normal hearts was carried out. The heart with a myocardial infarction was subjected to a programmed stimulus protocol to identify the effects of sex and anatomical detail on ventricular tachycardia inducibility. All female hearts presented QT-interval prolongation however the prolongation interval in comparison to the male phenotypes was anatomy-dependent and was not correlated to the size of the heart. Detailed geometries showed QRS fractionation and increased T-wave magnitude in comparison to the corresponding smoothed geometries. A variety of sustained VTs were obtained in the detailed and smoothed male geometries at different pacing locations, which provide evidence of the geometry-dependent differences regarding the prediction of the locations of reentry channels. In the female phenotype, sustained VTs were induced in both detailed and smooth geometries with RV apex pacing, however no consistent reentry channels were identified. Anatomical and physiological cardiac features play an important role defining risk in cardiac disease. These are often excluded from cardiac electrophysiology simulations. The assumption that the cardiac endocardium is smooth may produce inaccurate predictions towards the location of reentry channels in in-silico tachycardia inducibility studies.
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Caracteres Sexuais , Taquicardia Ventricular , Feminino , Masculino , Humanos , Ventrículos do Coração , Coração , Arritmias Cardíacas , Simulação por Computador , Estimulação Cardíaca Artificial , EletrocardiografiaRESUMO
Aortic valve fenestrations are defined as a loss of aortic valve leaflet tissue. They are a common but overlooked finding with unclear significance. The aim of this study was to investigate the varied functional anatomies of aortic valve fenestrations. A total of 400 formalin-fixed autopsied human hearts were macroscopically assessed and the function of the aortic valve of 16 reanimated human hearts were imaged using Visible Heart® methodologies. Aortic valve leaflet fenestrations were present in 43.0% of autopsied hearts (in one leaflet in 24.0%, in two leaflets 16.0%, in all leaflets 3.0%). Fenestrations were mostly present in left (25.5%) followed by right (23.3%) and noncoronary leaflet (16.3%). In 93.8% of cases, the fenestrations form clusters and were mainly located at the free edge of the leaflet in the commissural area (95.4%). Hearts with aortic valve fenestrations had significantly larger aortic valve diameters and aortic valve areas (p < 0.001). The average surface area sizes of fenestrations were 23.8 ± 16.6 mm2 , and the areas were largest for left followed by right and noncoronary leaflet fenestrations (p < 0.001). The fenestration areas positively correlated with donor age (r = 0.31; p = 0.02). Significant hypermobility and subjective weakening of the leaflet adhesion levels of the fenestrated regions were observed. In conclusion, fenestrations of the aortic leaflets are frequent, and their sizes may be significant. They occur in all age groups, yet their size increase with aging. Fragments of leaflets with fenestrations show different behaviors during the cardiac cycle versus unchanged areas.