Double Outlet Research Articles

Decreased clinical performance in TGA-ASO patients after RVOT re-interventions; multicenter European collaboration

Abstract Background In patients with transposition of the great arteries and an arterial switch operation (TGA-ASO) right ventricular outflow tract (RVOT) obstruction is a common complication requiring one or more RVOT reinterventions. However, data on the impact of reinterventions on clinical performance is scarce. Therefore, we aimed to assess in TGA-ASO patients the cardiopulmonary exercise capacity (CPET) and right ventricular function stratified for the number of RVOT reinterventions. Method This multicenter observational study was performed in adult (≥16 years) TGA-ASO patients from the EPOCH (European Collaboration for Prospective Outcome Research in Congenital Heart disease). All patients underwent a comprehensive clinical workup including CPET and echocardiography, including right ventriculo-arterial (VA) coupling (defined as tricuspid annular plane systolic excursion (TAPSE) / right ventricular systolic pressure (RVSP) ratio). Patients were stratified for the number of reinterventions at the RVOT, including re-interventions at the pulmonary valve, main pulmonary artery and pulmonary branches. Association between RVOT re-intervention(s) and functional parameters, including predicted (%) peak oxygen uptake (peak VO2), TAPSE, right ventricle (RV) S’ and VA coupling of the RV were analyzed with linear regression. Results A total of 449 TGA patients were included in this study, with a mean age of 25.4 ± 5.6 years and median time until ASO was 8 days [IQR 6-15]. Eleven (2.5%) patients with previous re-interventions at the left ventricular outflow tract (LVOT) or aortic arch were excluded from the analysis. Twenty-six percent of the included patients had a ventricular septal defect (VSD) and 1.6% were diagnosed with double outlet right ventricle (DORV). In the total cohort, 13% of the patients had 1 previous RVOT re-intervention, 8% had 2 RVOT re-interventions and 5% had 3 RVOT re-interventions. Patients had echocardiographic examination and 55% underwent CPET. Predicted VO2peak was significantly reduced in patients with 1 RVOT re-intervention (72%), 2 RVOT re-interventions (69%) and 3 RVOT re-interventions (71%) compared to patients without any-reintervention (77%) (p=0.0268). Right VA coupling was a significant predictor (p=0.017) for reduced hemodynamic performance in patients with 1 RVOT re-intervention (0,50), 2 RVOT re-interventions (0,51) and 3 RVOT re-interventions (0,26). Conclusion In TGA-ASO patients, RVOT reinterventions were associated with a reduced clinical performance. VA coupling of the right ventricle was the most sensitive marker for hemodynamic performance in TGA-ASO patients.

Abstract 13304: Intrinsic Morphology Influences the Natural History of Neo-Aortic Root Dilatation and Pathologic Neo-Aortic Regurgitation in Transposition of the Great Arteries

Introduction: Neo-aortic root dilatation and pathologic neo-aortic regurgitation (AR) can lead to significant late morbidity after the arterial switch operation (ASO) for dextro-transposition of the great arteries (dTGA). Hypothesis: The natural history of root dilatation in dTGA is influenced by intrinsic morphology. Aims: To i) delineate the natural history of root dilatation in repaired dTGA and ii) to histologically characterize the great arteries in unrepaired dTGA. Methods: A single-center review of patients who underwent the ASO from 07/1981-09/2022 was performed. Morphology was categorized as dTGA with intact ventricular septum (dTGA-IVS), dTGA with ventricular septal defect (dTGA-VSD), and double outlet right ventricle-TGA type (DORV-TGA). Echocardiographically-determined diameters and derived z-scores were measured at the annulus, sinus of Valsalva (SoV), and sinotubular junction (STJ) immediately before the ASO and throughout follow-up. Linear mixed-effects models assessed trends in dimensions over time. We also histologically examined the aortic and pulmonary roots of 10 cases of unrepaired dTGA from our Cardiac Registry. Results: Of 1359 patients meeting entry criteria, 593 (44%) had dTGA-IVS, 666 (49%) had dTGA-VSD, and 100 (7%) had DORV-TGA. At a median follow-up of 8.3 years (range 0.1-39.3 years), 129 (9.5%) patients had ≥moderate AR or required a neo-aortic valve or root reoperation ( Fig-A ). Overall growth of the root is shown in Fig-B . At baseline, there were no differences in annular, SoV, or STJ diameters between dTGA-IVS patients and dTGA-VSD or DORV-TGA patients. At 30 years, DORV-TGA patients had significantly larger diameters at the annulus (p<0.001), SoV (p=0.039), and STJ (p=0.041) relative to dTGA-IVS patients ( Fig-C ). Specimens of the aortic and pulmonary roots from a representative case of unrepaired dTGA are shown in Fig-D . Conclusions: Longitudinal surveillance of the neo-aortic root is warranted long after the ASO.

Study on spray cooling characteristics of dry ice particles for IGBT in high-speed trains{fr}Etude des caractéristiques de refroidissement par pulvérisation des particules de glace sèche pour l'igbt dans le train à grande vitesse

Aiming at the high efficiency cooling problem of IGBT(Insulated Gate Bipolar Transistor) module of traction converter for high-speed Train, a method of spray cooling with natural dry ice particles was proposed. The heat sinks with pin-fin and straight-fin structure were designed, and the heat sinks with optimum structure size selected by simulation were developed, and the heat sinks were provided with visual shells, as well as single outlet, double outlet and four outlet of the three different ways of outlet. The gas-solid two-phase flow, heat and mass transfer characteristics of dry ice particles in the heat sinks were studied by means of simulation and experiment. By comparison, it is found that the flow and heat transfer in the pin-fin heat sink have a good cooperation, and it is most suitable for the IGBT module with spray cooling of dry ice particles, which can reduce the temperature of IGBT from 70 ℃ to 55 ℃ in 75 s, compared with the fin-free heat sink, the heat transfer performance is improved by 12 %, and the double-outlet pin-fin heat sink has the best effect, the temperature difference of the heat transfer substrate is 19.8 ℃, and the average temperature of the heat transfer substrate is only 22.5 ℃ compared with that of the open type, which is 27.3 ℃ lower. Double outlet dry ice particles spray pin-fin heat sink is an efficient heat sink, thermal resistance is only 0.066 K/W, it can meet the current practical application of high-speed train cooling needs, solve the problem of heat dissipation of IGBT module for high-speed train, it lays a foundation for the development of dry ice particles spray heat sink.

Abstract 13256: Efficient and Precise Phenotyping of Murine Fetal Hearts by Means of Synchrotron-Based Phase-Contrast Micro-Computed Tomography

Mouse models are routinely utilized to investigate the role of genes in congenital heart disease. Cardiovascular phenotyping is, however, quite challenging because of the small size of fetal mouse hearts. The most used method is histological assessment, which typically provides only two-dimensional information and thus might overlook important structural defects. Three-dimensional (3D) methods with sufficient resolution are either time-consuming, require specific sample preparation and/or selective staining, or cause destruction of the sample. Here, synchrotron radiation-based phase-contrast micro-computed tomography (SRμCT) was evaluated for fast and precise phenotyping of unstained, intact murine fetal hearts in a non-destructive way. Embryonic day (E) 18.5 hearts from control mice and mice that lack the secreted protease ADAMTS6 were formalin-fixed, paraffin-embedded and then scanned with SRμCT at the TOMCAT beamline (Swiss Light Source) with a 1.63 μm effective pixel size. Following SRμCT, the hearts were sectioned and processed for standard hematoxylin and eosin staining (H&E), and for specific immunofluorescence staining. SRμCT enabled evaluation of the hearts with a high level of detail. A full E18.5 mouse heart was scanned in less than 3 minutes, followed by virtual sectioning along arbitrary slicing planes and 3D rendering for morphological assessment. The resolution proved sufficient to trace minute features like the coronary arteries. In the Adamts6 knockouts, malformations such as a ventricular septal defect and double outlet right ventricle could be readily diagnosed. We also explored the potential of merging stained sections with SRμCT. In summary, SRμCT has the potential to become a powerful tool for fast phenotyping of mutant mouse models. The combination of 3D imaging with subsequent sectioning and methods like histology, immunohistochemistry and in situ hybridization will uncover pathophysiological mechanisms in 3D space.

Abstract 16255: Unraveling the Complex Interplay: Atrial Flutter in a Patient With Prior Double Outlet Right Ventricular Repair

Introduction: Double Outlet Right Ventricle (DORV) is a rare complex congenital heart disease (CHD) in which both the great arteries arise predominantly or entirely from the right ventricle. It is one of the rare CHD lesions with a prevalence of about 0.9%. These patients have complex anatomy, which increases their risk of recurrent arrhythmias. We present a challenging case of Atrial Flutter (AFL) in a patient with DORV. Case: A 31-year-old male with a history of DORV repair presented with palpitations and chest pain for 2 days. His heart rate (HR) was 240 bpm. EKG showed AFL with variable block [Figure 1]. Labs were unremarkable. The patient remained in AFL with HR above 120 bpm despite receiving diltiazem and adenosine. Considering his underlying complex anatomy, ablation was deferred, and the patient was cardioverted to sinus rhythm [Figure 1]. A loop monitor was placed and was started on flecainide with outpatient follow-up at a higher centre. Discussion: Infundibulotomy, removal of obstructive muscle bundles, and a patch to widen the passageway from the right ventricle to the pulmonary arteries are all steps in DORV repair. These surgeries result in scar tissue, an akinetic right ventricular outflow tract, and pulmonary valve insufficiency. Reentrant tachycardias may form due to surgical scars. In DORV patients, Atrial tachyarrhythmias have undesirable outcomes resulting in congestive heart failure, stroke, and mortality. Antiarrhythmics and cardioversion are the cornerstones of managing AFL in patients with DORV due to increased failure rates of catheter ablation. Conclusion: This case illustrates persistent atrial arrhythmias more likely due to DORV repair, resulting in cardiac remodeling. The abnormal anatomy makes localization of irritated ectopic foci and ablations ineffective and difficult.

Double outlet right ventricle.

This review article addresses the history, morphology, anatomy, medical management, and different surgical options for patients with double outlet right ventricle.

Prevalence of Congenital Heart Defects in Term Children in the First Month of Life in the Arkhangelsk Region

The article presents an analysis of the incidence of congenital heart defects in children of the first month of life in one of the cities of the Arkhangelsk region for 5 years. The results of echocardiography of full-term infants in the first month of life, carried out in 2018-2022, were analyzed. The total number of full-term children in the first month of life who underwent echocardiography during the reporting period was 1112 people. The incidence of all CHD was 3.1%, while the most common CHD was atrial septal defect and accounted for 47% of all identified CHD. In second place in terms of prevalence is the defect of the interventricular septum, in the third place is the patent ductus arteriosus. Coarctation of the aorta was detected in 5.9% of patients; it was not critical and required only dynamic monitoring. Stenosis of the pulmonary artery was not detected during this period of time, but moderate stenosis of the branches of the pulmonary arteries (right and left) was detected in 0.36% of patients due to narrowing of their trunks. The prevalence of complex combined heart defects was 1.8% (tetralogy of Fallot with severe pulmonary artery stenosis, double outlet vessels from the right ventricle).

Toward a better understanding of a rare fetal heart condition

Evaluating the dynamics of Double Outlet Right Ventricle can improve treatments and save lives.

Outcomes of atrioventricular septal defects with and without down syndrome: analysis of the national inpatient database.

Controversial data exist about the impact of Down syndrome on outcomes after surgical repair of atrioventricular septal defect. (A) assess trends and outcomes of atrioventricular septal defect with and without Down syndrome and (B) determine risk factors associated with adverse outcomes after atrioventricular septal defect repair. We queried The National Inpatient Sample using International Classification of Disease codes for patients with atrioventricular septal defect < 1 year of age from 2000 to 2018. Patients' characteristics, co-morbidities, mortality, and healthcare utilisation were evaluated by comparing those with versus without Down syndrome. In total, 2,318,706 patients with CHD were examined; of them, 61,101 (2.6%) had atrioventricular septal defect. The incidence of hospitalisation in infants with atrioventricular septal defect ranged from 4.5 to 7.5% of all infants hospitalised with CHD per year. A total of 33,453 (54.7%) patients were associated with Down syndrome. Double outlet right ventricle, coarctation of the aorta, and tetralogy of Fallot were the most commonly associated with CHD in 6.9, 5.7, and 4.3% of patients, respectively. Overall atrioventricular septal defect mortality was 6.3%. Multivariate analysis revealed that prematurity, low birth weight, pulmonary hypertension, and heart block were associated with mortality. Down syndrome was associated with a higher incidence of pulmonary hypertension (4.3 versus 2.8%, p < 0.001), less arrhythmia (6.6 versus 11.2%, p < 0.001), shorter duration for mechanical ventilation, shorter hospital stay, and less perioperative mortality (2.4 versus 11.1%, p < 0.001). Trends in atrioventricular septal defect hospitalisation had been stable over time. Perioperative mortality in atrioventricular septal defect was associated with prematurity, low birth weight, pulmonary hypertension, heart block, acute kidney injury, and septicaemia. Down syndrome was present in more than half of atrioventricular septal defect patients and was associated with a higher incidence of pulmonary hypertension but less arrhythmia, lower mortality, shorter hospital stay, and less resource utilisation.

Analysis of the distribution and orientation of oxygenated and non-oxygenated blood in a double outlet right ventricle

Double outlet right ventricle (DORV) is a malformation of the fetal heart in utero that affects the ventricular chambers. It usually presents with a displacement of the aorta and more than half the circumference of both arterial valves in the right ventricle. A peculiar characteristic is given by an interventricular septal defect (VSD), which allows communication between the left ventricle and the right with consequent mixing of oxygenated and non-oxygenated blood inside the cavities. A crucial question in assessing the degree of severity of functional dysfunction concerns the percentage of oxygenated blood that is ejected into the primary circulation via the aorta, a result that depends on the details of the vortex flow pattern within the two ventricular chambers. This study analyzes a complete DORV case through the use of numerical simulations that allow to identify the concentrations of oxygenated and non-oxygenated blood passing through this geometry. Results show that the VSD presents a significant impact on the fluid dynamic performance of the two ventricles. The analysis of blood concentration allowed to quantify the presence of oxygenated blood ejected into the pulmonary artery and of non-oxygenated blood into the aortic artery. The analysis of this specific case aims to demonstrate how the fluid dynamics analysis of this rare malformation, properly coupled with imaging technology, can provide information that could not be obtained otherwise and that are relevant for a careful clinical management including timely therapeutic intervention.

Stenting for Left Ventricular Outflow Tract Stenosis after Double Outlet Right Ventricle Repair.

Stenting for Left Ventricular Outflow Tract Stenosis after Double Outlet Right Ventricle Repair.

RISK OF CARDIAC ANOMALIES IN ABERRANT RIGHT SUBCLAVIAN ARTERY RELATIVE AORTIC ARCH ANOMALIES FOR PEDIATRICS: A CROSS-SECTIONAL STUDY

Abstract Introduction: An aberrant right subclavian artery with a normal-sided left aortic arch is the most common congenital anomaly of the aorta. This study aims to determine the risk of cardiac anomalies associated with aberrant right subclavian artery in relation to aortic arch anomalies among pediatric patients. Material and methods: This prospective cross-sectional study was performed between 2008 and 2011. Patients with either clinical or echocardiographic findings of congenital heart disease were referred for complementary evaluation with computed tomography angiography. Results: Finally, 203 patients were included in this study. The prevalence of an aberrant right subclavian artery was presented in 24 patients (11.8%). Moreover, the most common aortic arch anomaly was coarctation 40 (19.7%). The only double outlet right ventricle cardiac abnormality was associated with a higher risk of an aberrant right subclavian artery (relative risk, 1.192; 95% CI, 0.179 – 7.95) relative to other aortic arch anomalies. Discussion: In conclusion, this study showed that the incidence of aberrant right subclavian artery in an extensive series of Aortic Arch Anomalies had been performed (11.8%). Furthermore, pulmonary atresia, total anomalous pulmonary venous return, aortic coarctation, cervical arch, aortic interruption, tubular hypoplasia, and pulmonary sling were significantly higher in the aberrant right subclavian artery group in contrast with Other Aortic Arch Anomalies. However, just double outlet right ventricle was associated with a higher risk of aberrant right subclavian artery.

Double Outlet Right Ventricle with Pulmonary Atresia and Antero-Posterior Malposition of Great Arteries: Transthoracic Echocardiographic Evaluation of a rare cyanotic congenital heart disorder

Double outlet right ventricle (DORV) is a heterogeneous group of abnormal ventriculoarterial connections where, by definition, both great arteries (pulmonary artery and aorta) arise primarily from the morphologically right ventricle, This condition affects 1-1.5% of the patients with congenital heart diseases, with a frequency of 1 in each 10,000 live births. We are reporting a case of seven year old deeply cyanotic child with DORV, subaortic VSD with rare anatomic features of antero-posterior malposition of great arteries (GA) and pulmonary vavular atresia, with conspicuous absence of patent ductusarteriosus (PDA) or major aorto-pulmonary collaterals (MAPCAs), despite the presence of atretic pulmonary valve. Keywords: DORV, Pulmonary atresia, TGA, VSD, subaortic VSD, overriding of Aorta, cyanotic congenital heart defects.

Atrioventricular conduction recovery immediately after the re-operation in a repaired CHD patient.

This is a case of a 2.7-year-old girl with trisomy 21 and double outlet right ventricle who underwent epicardial pacemaker system placement for a surgical atrioventricular block and achieved atrioventricular conduction recovery immediately after residual ventricular septal defect closure. Although ventricular pacing ratio was 100% before re-operation, it declined to approximately 25% on the 6th post-operative day and was <1% 3 years after re-operation.

Clinical course after Fontan palliation: Single center experience

BackgroundThe Fontan procedure has been the standard palliation for single-ventricle patients. We aimed to investigate the short- and midterm outcomes of patients who underwent Fontan palliation. ObjectivesTo assess and analyze the clinical course, including length of stay, complications, and mortality of single ventricle patients undergoing Fontan Palliation. MethodsRetrospective review of all patients who underwent Fontan palliation at the University of Minnesota, 2006–2020. The primary outcomes measured were length of stay, complications, and Fontan failure. ResultsOf the 55 patients the median age of Fontan was 3.9 yrs [2.63, 4.19] and the most common diagnoses were hypoplastic left heart syndrome (n = 20, 36 %), double inlet left ventricle (n = 11, 20 %) and double outlet right ventricle (n = 8, 15 %). Twenty-Seven were right ventricle dominant, 23 were left ventricle dominant, and 5 had biventricular morphology. The median hospital stay was 11 days [8, 17.5], an ICU stay of 6.5 days [4,9]. Fourteen late complications occurred in 10 patients. Three, all with HLHS, had Fontan failure leading to heart transplant. Four died: two prior to hospital discharge, one 6.7 yrs post-Fontan, and one 27 days after transplantation. Right ventricle morphology was associated with prolonged ICU (P 0.05), prolonged hospital stay (P < 0.01), and complications resulting in Fontan failure (P < 0.01). ConclusionThe survival following Fontan completion in the current era is excellent, with an overall and transplant-free survival at 5 and 10 years were at 96 % and 93 %. However, it is clear that univentricular physiology continues to present challenges, and patients remain at risk for morbidity, especially for patients with right ventricle morphology.

The retirement years of Doctor Helen B. Taussig: an intersection of art and medicine.

Dr Helen B. Taussig (1898-1986) worked a paediatric cardiologist at the Johns Hopkins University in Baltimore, Maryland from 1930 to 1963. Dr Taussig would become world-renowned for her contributions to the systemic-to-pulmonary artery shunt to treat congenital heart patients with cyanosis. This shunt would eventually be named after the surgeon/cardiologist as the Blalock-Taussig shunt. Dr Taussig's name was also attached to the description of one form of double outlet right ventricle called the Taussig-Bing malformation. Dr Taussig ultimately received the Presidential Medal of Freedom in 1964 as a testimony to her life-long contributions to the field of congenital heart surgery.In 1963, Dr Taussig retired from clinical practice but continued her teaching and academic pursuits at Johns Hopkins for another 14 years. Upon her "second retirement" in 1977, she moved to Kennett Square, PA. This paper will review the retirement years of Dr Helen Taussig and the curious intersection between art and medicine.

Outcomes after implantation of right-sided mechanical valve prostheses in congenital heart disease

BackgroundBioprosthetic valves are often used for pulmonary valve replacement (PVR) and tricuspid valve replacement (TVR) because of concerns about mechanical valve thrombosis in the right heart. The purpose of this...

Ten-year follow-up of dilatation of aortic structures in Fallot-type anomalies.

Dilatation of the aortic root structures or ascending aorta is often observed in patients with Fallot-type anomalies. We aimed to determine the dilation rate of the aortic structures and investigate strategies for managing this phenomenon. In this retrospective study, we enrolled 66 out of 801 patients who underwent corrective surgery for Fallot-type anomalies (tetralogy of Fallot [TOF] and Fallot-type double outlet right ventricle [DORV]) between 2004 and 2020. These 66 patients had follow-up cardiac computed tomography (CT) angiography images taken at least 5years after the initial CT study. We analyzed the diameters and aortic cross-sectional area/height ratio (AH) of the aortic annulus, sinus of Valsalva, sinotubular junction, and ascending aorta between the initial and follow-up CT scans. "Dilatation" was defined as a z-score over 2 for each aortic structure. The median age at the initial and follow-up CT scans was 5.9years (interquartile range [IQR]: 0.4 ~ 12.4) and 15.9years (IQR 9.3 ~ 23.4), respectively. The median CT interval (from initial to latest CT) was 9.5years (IQR 6.6 ~ 12.0). The sinus of Valsalva exhibited the most significant dilation (32.8mm at follow-up CT) over the study period. The AH ratio increased significantly in all four aortic structures. The patient's age was significantly associated with higher AH in the follow-up CT. Aortic dilatation was present in 74.2% of patients at the initial CT and increased to 86.4% at the follow-up CT. In Fallot-type anomalies, the AH ratio of aortic root structures significantly increased over an average period of approximately 9.5years. The number of patients diagnosed with aortic dilatation also increased. Based on our observations in this study, these patients' group should be considered for more frequent follow-up examinations, as significant dilatation could occur in their mid-20s.

A case report of Y-shaped bi-directional Fontan procedure: promising long-term outcomes for single ventricle physiology patients

BackgroundAchieving optimal hepatic factor distribution and total cavopulmonary resistance is crucial for long-term outcomes in single ventricle palliation patients. Y-shaped Gore-Tex Fontan procedure redirects hepatic drainage to both the right and left pulmonary arteries. The aim of this approach is to achieve bilateral pulmonary distribution of hepatic factors and reduce the risk of arteriovenous malformations that can develop in single-ventricle patients.Case presentationWe present a unique case of a 20 years old female with symptoms of heart failure, who has a history of complex heterotaxy with polysplenia, interrupted Inferior vena-cava, and double outlet right ventricle with unbalanced atrio-ventricular septal defect, d-malposed great arteries, and pulmonary atresia. Fenestrated Y-shaped Gore-Tex Fontan procedure was successfully done which was confirmed by performing cardiac CT angiography.ConclusionsStudies have shown that achieving balanced hepatic factor distribution and low resistance in the Fontan pathway can improve long-term outcomes. This procedure has demonstrated positive results in terms of oxygen saturation and reduced asymmetric blood flow distribution. Level of Evidence Level 4, Case Report.

Double Outlet Right Ventricle with Pentalogy Physiology in Adult Women: A Case Report

Double right ventricle outlet (DORV) is a rare cardiac abnormality, especially in adult life. DORV is a rare and complex congenital heart disease that has a high rate of genetic anomalies and extracardiac pathologies. Echocardiography plays an important and cost-effective role in the diagnosis of complex congenital cardiac diseases and assists in surgical planning. Here, we present a case of 38 years old woman who came to our outpatient department with shortness of breath which was progressive during exertion but relief on rest. Clinical examination showed low oxygen saturation of 70% without clubbing of fingers and toes. Holosystolic murmur and diastolic regurgitant murmur were audible along the left Sternal border. Chest X-ray showed cardiomegaly and enlarged pulmonary trunks. Electrocardiography showed right axis deviation and biventricular hypertrophy. After the echocardiogram, it turned out she had DORV. The study emphasizes the role of echocardiography in evaluating DORV.