Unsupervised synthesis of realistic coronary artery X-ray angiogram.

PURPOSE: Medical image analysis suffers from a sparsity of annotated data necessary in learning-based models. Cardiorespiratory simulators have been developed to counter the lack of data. However, the resulting data often lack realism. Hence, the proposed method aims to synthesize realistic and fully customizable angiograms of coronary arteries for the training of learning-based biomedical tasks, for cardiologists performing interventions, and for cardiologist trainees. METHODS: 3D models of coronary arteries are generated with a fully customizable realistic cardiorespiratory simulator. The transfer of X-ray angiography style to simulator-generated images is performed using a new vessel-specific adaptation of the CycleGAN model. The CycleGAN model is paired with a vesselness-based loss function that is designed as a vessel-specific structural integrity constraint. RESULTS: Validation is performed both on the style and on the preservation of the shape of the arteries of the images. The results show a PSNR of 14.125, an SSIM of 0.898, and an overlapping of 89.5% using the Dice coefficient. CONCLUSION: We proposed a novel fluoroscopy-based style transfer method for the enhancement of the realism of simulated coronary artery angiograms. The results show that the proposed model is capable of accurately transferring the style of X-ray angiograms to the simulations while keeping the integrity of the structures of interest (i.e., the topology of the coronary arteries).

Patient-specific Cardio-respiratory Motion Prediction in X-ray Angiography using LSTM Networks.

Objective.To develop a novel patient-specific cardio-respiratory motion prediction approach for X-ray angiography time series based on a simple long short-term memory (LSTM) model.Approach.The cardio-respiratory motion behavior in an X-ray image sequence was represented as a sequence of 2D affine transformation matrices, which provide the displacement information of contrasted moving objects (arteries and medical devices) in a sequence. The displacement information includes translation, rotation, shearing, and scaling in 2D. A many-to-many LSTM model was developed to predict 2D transformation parameters in matrix form for future frames based on previously generated images. The method was developed with 64 simulated phantom datasets (pediatric and adult patients) using a realistic cardio-respiratory motion simulator (XCAT) and was validated using 10 different patient X-ray angiography sequences.Main results.Using this method we achieved less than 1 mm prediction error for complex cardio-respiratory motion prediction. The following mean prediction error values were recorded over all the simulated sequences: 0.39 mm (for both motions), 0.33 mm (for only cardiac motion), and 0.47 mm (for only respiratory motion). The mean prediction error for the patient dataset was 0.58 mm.Significance.This study paves the road for a patient-specific cardio-respiratory motion prediction model, which might improve navigation guidance during cardiac interventions.

Navigation guidance for ventricular septal defect closure in heart phantoms.

PURPOSE: Transesophageal echocardiography (TEE) is the preferred imaging modality in a hybrid procedure used to close ventricular septal defects (VSDs). However, the limited field of view of TEE hinders the maneuvering of surgical instruments inside the beating heart. This study evaluates the accuracy of a method that aims to support navigation guidance in the hybrid procedure. METHODS: A cardiologist maneuvered a needle to puncture the patient's heart and to access a VSD, guided by information displayed in a virtual environment. The information displayed included a model of the patient's heart and a virtual needle that reproduced the position and orientation of the real needle in real time. The physical and the virtual worlds were calibrated with a landmark registration and an iterative closest point algorithms, using an electromagnetic measurement system (EMS). For experiments, we developed a setup that included heart phantoms representing the patient's heart. RESULTS: Experimental results from two pediatric cases studied suggested that the information provided for guidance was accurate enough when the landmark registration algorithm was fed with coordinates of seven points clearly identified on the surfaces of the physical and virtual hearts. Indeed, with a registration error of 2.28 mm RMS, it was possible to successfully access two VSDs (6.2 mm and 6.3 mm in diameter) in all the attempts with a needle (5 attempts) and a guidewire (7 attempts). CONCLUSION: We found that information provided in a virtual environment facilitates guidance in the hybrid procedure for VSD closure. A clear identification of anatomical details in the heart surfaces is key to the accuracy of the procedure.

Characterization of blood-mimicking fluids for echocardiography imaging of ventricular septal defects.

PURPOSE: Ventricular septal defects (VSD) are congenital heart malformations and, in severe cases, they require complex interventions under echocardiography guidance. Heart phantoms can be helpful to train and to understand the complex hemodynamics of VSD. The goal of this study was to characterize the best blood mimicking fluids in such heart phantoms for modelling the hemodynamics of VSD patients using echocardiography. METHODS: Four fluid compositions were considered. Distilled water was used as a baseline, while the other three fluids were developed based on physical properties of human blood, such as the viscosity and the refractive index. Three bi-ventricular heart phantoms of three different pediatric patients with complex VSD were designed from preoperative CT imaging. Custom molds were printed in 3-D and the anatomical structure was casted in polyvinyl alcohol cryogel. The VSD in each heart phantom were observed using echocardiography and color Doppler imaging was used for the hemodynamic study. RESULTS: Heart phantoms with blood mimicking fluids of 30% glycerol and 27% glycerol, 10% sodium iodide were found to be anatomically realistic under echocardiography imaging. Hemodynamic parameters such as the pressure gradient and the volume of the shunt were characterized using color Doppler imaging. CONCLUSION: Proper composition of blood mimicking fluids are important for improving the realism in echocardiographic heart phantoms and they contribute to better understand the complex hemodynamic of VSD under echocardiography.

The Fontan Circulation: From Ideal to Failing Hemodynamics and Drug Therapies for Optimization.

Fontan palliation results in a hemodynamically complex circulation with multisystem consequences, which in the long term adversely affect many body processes. Systemic venous hypertension, nonpulsatile low-shear pulmonary blood flow, and low cardiac output are the 3 main characteristics of a Fontan circulation, leading to unavoidable slowly progressive failure. An appreciation of how the hemodynamics of a Fontan circulation change with time and relate to the various modes of Fontan circulatory failure is important. Accurate hemodynamic assessment aid this understanding and may permit early identification of potentially treatable drivers of decline. While no evidence-based or guideline-directed pharmacologic management strategy has been established in Fontan patients, understanding the hemodynamics of Fontan circulation failure will assist in the rational selection of potentially helpful drug therapies for individual patients. In this review, we present hemodynamic concepts of the optimal Fontan physiology and Fontan circulatory failure, review practical aspects of invasive hemodynamic assessment, and discuss the role of drug therapies in increasing systemic venous blood flow return and decreasing ventricular filling pressures in Fontan circulation. Often complementary to catheter-based or surgical interventions, pharmacologic management aims at preserving patency of the circuit, adequate systolic and diastolic ventricular function, atrioventricular valve function, an unobstructed ventricular outflow tract, and pulmonary vascular integrity in order to maintain an acceptable cardiac output.

Generative learning approach for radiation dose reduction in X-ray guided cardiac interventions.

BACKGROUND: Navigation guidance in cardiac interventions is provided by X-ray angiography. Cumulative radiation exposure is a serious concern for pediatric cardiac interventions. PURPOSE: A generative learning-based approach is proposed to predict X-ray angiography frames to reduce the radiation exposure for pediatric cardiac interventions while preserving the image quality. METHODS: Frame predictions are based on a model-free motion estimation approach using a long short-term memory architecture and a content predictor using a convolutional neural network structure. The presented model thus estimates contrast-enhanced vascular structures such as the coronary arteries and their motion in X-ray sequences in an end-to-end system. This work was validated with 56 simulated and 52 patients' X-ray angiography sequences. RESULTS: Using the predicted images can reduce the number of pulses by up to three new frames without affecting the image quality. The average required acquisition can drop by 30% per second for a 15 fps acquisition. The average structural similarity index measurement was 97% for the simulated dataset and 82% for the patients' dataset. CONCLUSIONS: Frame prediction using a learning-based method is promising for minimizing radiation dose exposure. The required pulse rate is reduced while preserving the frame rate and the image quality. With proper integration in X-ray angiography systems, this method can pave the way for improved dose management.

Ventricular Arrhythmias and Sudden Death Following Percutaneous Pulmonary Valve Implantation in Pediatric Patients.

Reports have suggested a transient increase in ventricular ectopy early after percutaneous pulmonary valve implantation (PPVI). Little is known about the potential for more serious ventricular arrhythmias (VA) in children who undergo PPVI. We sought to evaluate the incidence of severe VA following PPVI in a pediatric population and to explore potential predictive factors. A retrospective cohort study was conducted of patients who underwent PPVI under 20 years of age in our institution from January 2007 to December 2019. The primary outcome of severe VA was defined as sustained and/or hemodynamically unstable ventricular tachycardia (VT), inducible sustained VT, or sudden death of presumed arrhythmic etiology. A total of 21 patients (mean age 16.2 ± 2.1 years; 66.7% male) underwent PPVI. The majority of patients (N = 15; 71.4%) had tetralogy of Fallot (TOF) or TOF-like physiology, with the most common indication being pulmonary insufficiency (N = 10; 47.6%). During a median follow-up of 29.6 months (IQR 10.9-44.0), severe VA occurred in 3 (14.3%) patients aged 15.6 (IQR 14.7-16.1) a median of 12.3 months (IQR 11.2-22.3) after PPVI. All events occurred in patients with TOF-like physiology following Melody valve implant. In conclusion, severe VA can occur long after PPVI in a pediatric population, particularly in those with TOF-like physiology. Further studies are required to elucidate underlying mechanisms and assess strategies to mitigate risks.

Balloon Atrial Septostomy: Does the Balloon Size Matter?

Background: Dextro-transposition of the great arteries is a congenital heart defect with eventually lethal life-threatening consequences of hypoxic low cardiac output. When a balloon atrial septostomy (BAS) is needed, it is performed shortly after birth to create an interatrial shunt and improve systemic blood oxygenation and haemodynamic conditions. In 2019 and 2020, the withdrawal of some balloon atrioseptostomy catheters from the market led to increased use of catheters with different materials, shapes, and sizes. The main objective of this study was to investigate whether the size of the Miller and Fogarty balloon (Edwards Lifesciences) in its 2 variations, the 4.0 cc and the 1.8 cc, had a different impact on the systemic oxygen saturation, on the atrial septal defect (ASD) size, or on the type and frequency of procedure-related complications. Methods: We conducted a retrospective study on 134 consecutive patients diagnosed with dextrotransposition of the great arteries between 2002 and 2018 who underwent BAS in a tertiary paediatric hospital in Canada. Results: BAS resulted in a significant increase in oxygen saturation of 18.91% ± 12.95% points (P < 0.0001) and a significant increase in the resulting ASD by 3.92 ± 1.58 mm (P < 0.0001). There was no significant difference in resulting oxygen saturation (P = 0.8370) or the final ASD size (P = 0.2193) based on the balloon size. Severe or life-threatening complications were rare (1%) with no subsequent patient demise. Conclusions: This is the first study to show that the small balloon is as efficient as the large balloon catheter including in premature patients. This raises the question whether different balloon sizes are necessary.

Contexte: La dextro-transposition des gros vaisseaux (dTGV) est une cardiopathie congénitale dont les conséquences peuvent être mortelles en raison du bas débit cardiaque et de l'état hypoxique. Lorsqu'une septostomie auriculaire par ballonnet est nécessaire, l'intervention est réalisée après la naissance pour créer une communication interauriculaire (CIA); cette ouverture améliore l'oxygénation de la circulation sanguine systémique ainsi que les conditions hémodynamiques. En 2019 et en 2020, le retrait du marché de certains cathéters utilisés lors des septostomies auriculaires par ballonnet a entraîné une hausse de l'usage de nouveaux cathéters offerts en différentes formes et tailles. L'objectif principal de cette étude était de déterminer si la différence de taille des ballonnets de Miller et de Fogarty (Edwards Lifesciences), respectivement de 4,0 cc et de 1,8 cc, a un effet sur la saturation en oxygène de la circulation sanguine systémique, sur la taille de la CIA ou sur le type et la fréquence des complications liées à l'intervention. Méthodologie: Nous avons mené une étude rétrospective comptant 134 patients consécutifs qui ont présenté une dTGV entre 2002 et 2018 et qui ont subi une septostomie auriculaire par ballonnet dans un hôpital pédiatrique tertiaire canadien. Résultats: Les septostomies auriculaires par ballonnet ont donné lieu à une hausse significative de 18,91 ± 12,95 points de pourcentage (p < 0,0001) de la saturation en oxygène et à une hausse significative de 3,92 ± 1,58 mm (p < 0,0001) de la CIA qui a résulté de l'intervention. La taille du ballonnet n'a pas entraîné de différence significative en ce qui concerne la saturation en oxygène qui a résulté de l'intervention (p = 0,8370) ou la taille finale de la CIA (p = 0,2193). Les complications graves ou mettant la vie du patient en danger ont été rares (1 %) et aucun patient n'est décédé suite à l'intervention. Conclusion: Il s'agit de la première étude qui démontre que le petit ballonnet est aussi efficace que le gros ballonnet, y compris chez les enfants prématurés. Cette conclusion soulève la question à savoir si différentes tailles de ballonnets sont nécessaires.

Design of heart phantoms for ultrasound imaging of ventricular septal defects.

PURPOSE: Ventricular septal defects (VSDs) are common congenital heart malformations. Echocardiography used during VSD hybrid cardiac procedures requires extensive training for image acquisition and interpretation. Cardiac surgery simulators with heart phantoms have shown usefulness for such training, but they are limited in visualization and characterization of complex VSD. This study explores a new method to build patient-specific heart phantoms with VSD, with proper tissue echogenicity for ultrasound imaging. METHODS: Heart phantoms were designed from preoperative imaging of three patients with complex VSDs. Each whole heart phantom, including atrial and ventricular septums, was obtained by manual segmentation and by surface reconstruction, then by molding and by casting in different materials. Heart phantoms in silicone and polyvinyl alcohol cryogel (PVA-C) were considered, and they were reconstructed in 3-D using 2-D freehand ultrasound imaging. RESULTS: An electromagnetic measurement system was used to measure the mean VSD diameters from the heart phantoms. Errors were evaluated below 1.0 mm for mean VSD diameters between 6.2 and 7.5 mm. CONCLUSION: Patient-specific heart phantoms promise for representing complex heart malformations such as VSDs. PVA-C showed better tissue echogenicity than silicone for VSDs visualization and characterization.

Supravalvular and Valvular Pulmonary Stenosis: Predictive Features and Responsiveness to Percutaneous Dilation.

Supravalvular pulmonary stenosis (SVPS) is considered a rare form of pulmonary stenosis (PS) and represents both a diagnostic and therapeutic challenge. There currently exist no reliable echocardiographic criteria to accurately predict the supravalvular form. The aims of the study were to describe the response to treatment of the different PS presentations and to outline the diagnostic capacity of echocardiogram to differentiate the SVPS from valvular PS (VPS). This retrospective study included 106 patients who underwent percutaneous angioplasty between 2006 and 2017. Interventional outcomes of patients with SVPS were compared to those of patients with VPS. Diagnosis of VPS vs. SVPS by echocardiogram was compared to diagnosis obtained by angiogram. Echocardiogram yielded a sensitivity of 56%, a specificity of 82.5%, a positive predictive value of 50%, and a negative predictive value of 85.7%. Patients with SVPS had a significantly smaller pulmonary artery to pulmonary valve (PA:PV) ratio. At 6-12 months of follow-up, the VPS group had a mean right ventricular to pulmonary artery (RV-PA) gradient of 21.68 ± 19.85 mmHg compared to 45.27 ± 24.58 mmHg in the SVPS group. Patients with SVPS had a higher rate of reintervention than patients with VPS (32% vs. 6.2%, p < 0.001). There was no difference in major complications between groups, whereas VPS patients had a higher proportion of pulmonary insufficiency. Percutaneous angioplasty for PS is less effective in patients with a supravalvular component. A better understanding of the underlying histopathology of different PS subtypes could lead to development of different techniques to improve outcomes, with fewer reinterventions, in this population.

Epistemic Uncertainty Modeling for Vessel Segmentation.

X-ray angiograms are currently the gold-standard in percutaneous guidance during cardiovascular interventions. However, due to lack of contrast, to overlapping artifacts and to the rapid dilution of the contrast agent, they remain difficult to analyze either by cardiologists, or automatically by computers. Providing, a general yet accurate multi-arteries segmentation method along with the uncertainty linked to those segmentations would not only ease the analysis of medical imaging by cardiologists, but also provide a required pre-processing of the data for tasks ranging from 3D reconstruction to motion tracking of arteries. The proposed method has been validated on clinical data providing an average accuracy of 94.9%. Additionally, results show good transposition of learning from one type of artery to another. Epistemic uncertainty maps provide areas where the segmentation should be validated by an expert before being used, and could provide identification of regions of interest for data augmentation purposes.

Model-free Cardiorespiratory Motion Prediction from X-ray Angiography Sequence with LSTM Network.

We present a novel model-free approach for cardiorespiratory motion prediction from X-ray angiography time series based on Long Short-Term Memory Recurrent Neural Networks (LSTM-RNN). Cardiorespiratory motion prediction is defined as a problem of estimating the future displacement of the coronary vessels in the next image frame in an X-ray angiography sequence. The displacement of the vessels is represented as a sequence of 2D affine transformation matrices allowing 2D X-ray registrations in a sequence. The new displacement parameters from a sequence of transformation matrices are predicted using an LSTM model. LSTM is a particular form of Recurrent Neural Network (RNN) architecture suitable for learning sequential data and predicting time series. The method was developed and validated by simulated data using a realistic cardiorespiratory motion simulator (XCAT). The results show that this method converges quickly and can predict the complex motion in the angiography sequences with irregularities. The mean values of prediction error over all the patients are approximately 0.29 mm (2 pixels) difference for the combination of both motions, 0.51 mm (3.5 pixels) difference for cardiac motion and 0.44 mm (3 pixels) difference for respiratory motion.

Percutaneous transmitral balloon commissurotomy using a single balloon with arteriovenous loop stabilisation: an alternative when there is no Inoue balloon.

BACKGROUND: The Inoue balloon technique is the standard technique for mitral valve balloon commissurotomy at this stage. However, the hardware for this technique is expensive and may not always be available in resource-limited settings. OBJECTIVE: This article reports our experience with percutaneous transmitral balloon commissurotomy using a single balloon (Nucleus) with arteriovenous loop stabilisation. METHOD: Eleven young patients, aged 12-26 years and weighing 23-48 kg, underwent transmitral balloon commissurotomy using the described technique at our centre from April to May 2014. RESULTS: Mean fluoroscopy time was 22.6 ± 6.4 min (18.5- 30.0). Mean transmitral gradient decreased from 24.1 ± 5.9 (16-35) to 6.6 ± 3.8 (3-14) mmHg, as measured on transoesophageal echocardiography. Mean mitral valve area increased from 0.69 ± 0.13 cm2 (range 0.5-0.9) before dilation to 1.44 ± 0.25 cm2 (1.1-1.9) after dilation (p < 0.001). Mean estimated pulmonary artery systolic pressure decreased from 110.0 ± 35 mmHg (75-170) before dilation to 28.0 ± 14.4 mmHg (range 10-60) after dilation. CONCLUSION: Our modified Nucleus balloon technique for mitral valve dilation in young patients with mitral stenosis is effective and safe. The technique differs from other over-the-wire techniques in that it avoids placing stiff wire in the left ventricle. It also offers better balloon stability and control owing to the arteriovenous loop. This technique may be easier for use by paediatric interventionists who might not be familiar with the Inoue balloon technique.

Contralateral Pulmonary Hypertension Following Resuscitation of Unilateral Ductal Origin of a Pulmonary Artery: A Multi-institutional Review.

In isolated unilateral ductal origin of a pulmonary artery (DOPA), intervention to establish reperfusion of the affected lung without direct re-anastomosis may lead to pulmonary hypertension (PH) in the contralateral lung. Multicenter retrospective review of patients with unilateral DOPA, who underwent palliation with a ductal stent (DS) or Blalock-Taussig (BT) shunt with subsequent development of PH in the contralateral lung, was conducted. Ten patients (4 females; median weight 3.2 kg, range 2.1-5.2) who underwent DS or BT shunt and developed contralateral PH were identified. Eight infants had right-sided DOPA. Stents/shunt used had a median diameter of 3.5 mm (range 2.5-5.2). After DS in 9 patients, 7 patients were exclusively treated with medical therapies, whereas 2 patients received intermediate procedures: one received an additional contralateral DS and other underwent surgical banding of the DS prior to PA reimplantation. Seven patients who underwent DS and one patient with BT shunt underwent PA reimplantation at median of 3.3 (0.6-18) months. PA pressure was documented to be normal in 5 patients immediately following PA reimplantation, 1 year later in 2 patients, and 1 patient is on Tadalafil with elevated PVR of 5.5 indexed Wood units. One patient died and one patient is awaiting surgery with normal PA pressure. We describe the development of severe contralateral PH following DS or BT shunt as the initial intervention for unilateral DOPA. Pulmonary hypertension resolved in 7/8 patients who underwent surgical PA reimplantation. The cause of PH in the normally connected lung in these cases remains unclear.

Automatic evaluation of vessel diameter variation from 2D X-ray angiography.

PURPOSE: Early detection of blood vessel pathologies can be made through the evaluation of functional and structural abnormalities in the arteries, including the arterial distensibility measure. We propose a feasibility study on computing arterial distensibility automatically from monoplane 2D X-ray sequences for both small arteries (such as coronary arteries) and larger arteries (such as the aorta). METHODS: To compute the distensibility measure, three steps were developed: First, the segment of an artery is extracted using our graph-based segmentation method. Then, the same segment is tracked in the moving sequence using our spatio-temporal segmentation method: the Temporal Vessel Walker. Finally, the diameter of the artery is measured automatically at each frame of the sequence based on the segmentation results. RESULTS: The method was evaluated using one simulated sequence and 4 patients' angiograms depicting the coronary arteries and three depicting the ascending aorta. Results of the simulated sequence achieved a Dice index of 98%, with a mean squared error in diameter measurement of [Formula: see text] mm. Results obtained from patients' X-ray sequences are consistent with manual assessment of the diameter by experts. CONCLUSIONS: The proposed method measures changes in diameter of a specific segment of a blood vessel during the cardiac sequence, automatically based on monoplane 2D X-ray sequence. Such information might become a key to help physicians in the detection of variations of arterial stiffness associated with early stages of various vasculopathies.

Initial clinical experience with the GORE® CARDIOFORM ASD occluder for transcatheter atrial septal defect closure.

OBJECTIVES: To report the initial clinical experience with a novel atrial septal defect (ASD) closure device, the GORE® CARDIOFORM ASD Occluder (GCO). BACKGROUND: Transcatheter closure has become the treatment of choice for secundum ASD. A wide range of occluder devices are available, but concern has been raised about the risk of cardiac erosion associated with rigid devices and future access to the left atrium METHODS: Retrospective chart review of patients treated with the GCO at three Canadian centers. Primary outcomes were procedural success and residual shunting at follow-up, as well as 30-day major adverse events. Secondary outcomes included new onset atrial arrhythmias, wire frame fractures (WFF), and all cause mortality. Clinical, echocardiographic, procedural data, and follow-up outcome variables were collected in each participating hospital. RESULTS: Between February and December 2015, 26 patients (5 children and 21 adults) underwent transcatheter ASD closure with the GCO and were included in the study cohort. Procedural success was achieved in 22 of 26 patients (85%) and no major procedural complications were observed. Two patients (8%) presented new onset atrial tachyarrhythmia during early follow-up (0-30 days). Follow-up echocardiography (median of 119 days [IQR: 92-146]) demonstrated no residual shunt in all implanted patients. After a median clinical follow-up of 174 days (IQR: 135-239), one patient died of an unrelated cause, there were no documented major adverse cardiovascular events. Fluoroscopic imaging of the device was performed in 20 patients (91%), and WFF was noted in five cases. No clinical consequence or device dysfunction was observed in these patients. CONCLUSIONS: In this first-in-man multicenter study, the GCO was safe and effective for ASD closure, with no major adverse events or residual shunt at follow-up. © 2017 Wiley Periodicals, Inc.

Shone Complex: An Under-recognized Congenital Heart Disease With Substantial Morbidity in Adulthood.

BACKGROUND: Shone complex consists of a constellation of left-sided, usually obstructive, cardiac lesions, including supravalvar mitral ring, parachute mitral valve, subaortic stenosis, and aortic coarctation. Incomplete Shone complex consists of a mitral valve anomaly associated with lesions involving the subaortic region, aortic valve, or thoracic aorta. There is a paucity of data regarding long-term outcomes in adults with Shone complex. METHODS: We reviewed records of adults with complete or incomplete Shone complex followed at the Montreal Heart Institute between 1982 and 2014. RESULTS: Among 4189 adults with congenital heart disease, 28 (0.67%) patients (mean age, 35 ± 11 years; 50% women) had complete or incomplete Shone complex and were followed for a median of 8 years. Only 39% were previously diagnosed as having Shone complex. The most common defects were congenital mitral stenosis (93%), aortic coarctation (75%), and bicuspid aortic valve (71%). Heart transplantation was required in 2 patients (7.1%) at age 22 and 28 years, respectively. Overall, 48% had cardiovascular hospitalizations during adulthood, predominantly for arrhythmias or heart failure. Freedom from cardiovascular intervention was 55%, 18%, and 8% at 10, 20, and 30 years of age, respectively. Although aortic coarctation was the most common indication for initial intervention (61%), adult interventions occurred predominantly for aortic valve/left ventricular outflow tract (60%) and mitral valve (33%) lesions. CONCLUSIONS: Shone complex is an under-recognized entity associated with relatively low mortality in adulthood but substantial morbidity related to arrhythmias, heart failure, and interventions. Increased awareness of this condition and associated complications may allow for more tailored follow-up.

A graph-based approach for spatio-temporal segmentation of coronary arteries in X-ray angiographic sequences.

The segmentation and tracking of coronary arteries (CAs) are critical steps for the computation of biophysical measurements in pediatric interventional cardiology. In the literature, most methods are focused on either segmenting the vessel lumen or on tracking the vessel centerline. However, they do not simultaneously combine the segmentation and tracking of a specific CA. This paper introduces a novel algorithm for CA segmentation and tracking from 2D X-ray angiography sequences. The proposed algorithm is based on the Temporal Vessel Walker (TVW) segmentation method, which combines graph-based formulation and temporal priors. Moreover, superpixel groups are used by TVW as image primitives to ensure a better extraction of the CA. The proposed algorithm, TVW with superpixels (SP-TVW), returns an accurate result to segment and track the artery along the angiogram. Quantitative results over 12 sequences of young patients show the accuracy of the proposed framework. The results return a mean recall of 84% in the dataset. In addition, the proposed method returned a Dice index of 70% in segmenting and tracking right coronary arteries and circumflex arteries. The performance of the proposed method surpasses the existing polyline method in tracking the centerline of CA with a more precise localization of the centerline, resulting in a smaller distance error of 0.23mm compared to 0.94mm.