Hemodynamic simulation of complete transposition of the great arteries for optimal treatment strategies based on its circulatory physiology.

Our study aimed to elucidate the role of different shunts and provide novel insights into optimal treatment approaches for complete transposition of the great arteries (TGA), which is characterized by unique and complicated circulatory dynamics. We constructed a computational cardiovascular TGA model and manipulated cardiovascular parameters, such as atrial septal defect (ASD) and patent ductus arteriosus (PDA) sizes, to quantify their effects on oxygenation and hemodynamics. In addition, ASD flow patterns were investigated as innovative indications for balloon atrial septostomy (BAS). Our model of TGA with an intact ventricular septum (TGA-IVS) showed that a large ASD can achieve sufficient mixing for survival without PDA, and the presence of PDA is detrimental to oxygen delivery. A treatment strategy for TGA-IVS that enlarges the ASD as much as possible by BAS and PDA closure would be desirable. In TGA with a ventricular septal defect (TGA-VSD), the VSD allows for higher oxygenation and reduces the detrimental effects of PDA on systemic circulation. In TGA-VSD, both strategies of enlarging the ASD by BAS with a closed PDA and adjusting the PDA in response to pulmonary vascular resistance (PVR) reduction without BAS may be effective. The simulated ASD flow patterns showed that the sharp peak left-to-right flow pattern in systole (σ-wave) reflected the hemodynamically significant ASD size, independent of PDA, VSD, and PVR. The ASD flow pattern visualized by Doppler echocardiography provides clinical insights into the significance of an ASD and indications for BAS, which are not readily apparent through morphological assessment.NEW & NOTEWORTHY Complete transposition of the great arteries (TGA) represents complex and unique circulation that is dependent on blood mixing through multiple interacting shunts. Consequently, the role of each shunt and the treatment strategy remain unclear. We developed a mathematical model of TGA circulation, revealing the significant influence of atrial septal defect (ASD) on oxygenation and hemodynamics. The blood flow pattern through the ASD reflects its hemodynamic impact and helps determine treatment strategies.

Atrial Mechanics, Atrial Cardiomyopathy and Impact of Atrial Interventions.

Our comprehension of atrial mechanics, atrial cardiomyopathy and their clinical implications across various cardiovascular conditions has advanced significantly. Atrial interventions can have differing effects on atrial mechanics. With the rapid increase in the use of atrial interventions, it is crucial for investigators and clinicians to acknowledge the potential adverse effects of these interventions on atrial mechanics that might not be clinically significant at the time of interventions. Recognizing the preclinical stage of atrial maladaptation might enable early interventions before the development of irreversible atrial remodeling and clinical manifestation. We review normal atrial function and mechanics, and atrial cardiomyopathy in select cardiovascular conditions. We also summarize and discuss the current evidence of the impact of various atrial interventions on atrial function and mechanics.

Recent Development of Biodegradable Occlusion Devices for Intra-Atrial Shunts.

Atrial septal defect (ASD) is the third most common type of structural congenital heart defect. Patent foramen ovale (PFO) is an anatomical anomaly in up to 25% of the general population. With the innovation of occlusion devices and improvement of transcatheter techniques, percutaneous closure has become a first-line therapeutic alternative for treatment of ASD and PFO. During the past few decades, the development of biodegradable occlusion devices has become a promising direction for transcatheter closure of ASD/PFO due to their biodegradability and improved biocompatibility. The purpose of this review is to comprehensively summarize biodegradable ASD/PFO occlusion devices, regarding device design, materials, biodegradability, and evaluation of animal or clinical experiments (if available). The current challenges and the research direction for the development of biodegradable occluders for congenital heart defects are also discussed.

Noninvasive Monitoring of Severe Pulmonary Artery Hypertension in Atrial Septal Defect Patients: Role of Serum Bilirubin Combined with Uric Acid.

Background: Atrial septal defect (ASD) patients commonly experience severe pulmonary arterial hypertension (SPAH), which is frequently associated with a poor prognosis. While serum bilirubin levels, indicative of liver function, are known predictors of right heart failure (RHF), their potential to differentiate SPAH in ASD patients is yet to be ascertained. The purpose of this study was to discover the potential correlations between serum bilirubin levels and ASD patients with SPAH. Methods: In this cross-sectional study, 102 ASD patients admitted from December 2019 to November 2020 were enrolled and divided into two cohorts: those with SPAH and those without. Blood tests were conducted to measure serum direct bilirubin (DBIL), total bilirubin (TBIL), alanine aminotransferase (ALT), aspartate aminotransferase (AST), uric acid (UA) and N-terminal pro B-type natriuretic peptide (NT-proBNP). Additionally, all participants underwent transthoracic echocardiography, and invasive hemodynamic data were gathered through right heart catheterization. Results: ASD patients with SPAH exhibited significantly elevated serum DBIL (5.2 ± 3.0 vs. 2.4 ± 1.5 µmol/L, p < 0.001) and TBIL (24.6 ± 20.7 vs. 10.1 ± 4.8 µmol/L, p < 0.001) levels in comparison to those without SPAH. However, ALT and AST levels remained comparable between the cohorts. Additionally, the SPAH cohort displayed higher serum UA (403.5 ± 131.6 vs. 317.8 ± 67.9 µmol/L, p < 0.001) and NT-proBNP levels. Serum DBIL levels, when analyzed independently of other variables, correlated with an increased risk of mean pulmonary arterial pressure (mPAP) in ASD patients ( ß = 1.620, p = 0.010). A DBIL concentration of 2.15 mg/dL effectively differentiated ASD patients with SPAH from those without, with a sensitivity of 92.9% and a specificity of 51.4% (area under the curve [AUC]: 0.794, 95% confidence interval [CI]: 0.701-0.886, p < 0.001). Notably, the combination of DBIL and UA had a higher sensitivity of 92.9% and specificity of 71.6% (AUC: 0.874, 95% CI: 0.799-0.949, p < 0.001). Conclusions: Elevated serum DBIL and TBIL levels in ASD patients with SPAH were correlated with poor cardiac function and heightened pulmonary artery pressure. The combination of DBIL and UA has emerged as a strong noninvasive predictor for SPAH in ASD patients, presenting a potentially novel therapeutic biomarker.

Right disc thrombosis of the new Gore Cardioform ASD Occluder.

BACKGROUND: The GCA is a well performing device in terms of efficacy despite complex anatomies (aortic rim <5 mm and ASD diameter >17 mm) with a good safety profile. AIMS: To evaluate atrial septal defect (ASD) features impacting on right disc device thrombosis in patients who underwent Gore Cardioform ASD Occluder (GCA) implantation. METHODS: A total of 44 consecutive patients undergoing percutaneous ASD with GCA device from January 2020 to September 2022 at our tertiary care Center were evaluated. The minimum follow-up was 6 months. RESULTS: The patients were stratified in two groups according to a cut-off value of ASD diameter equal to 20 mm at sizing balloon, derived from ROC analysis (AUC = 0.894; p = 0.024). Baseline characteristics were comparable between groups in terms of age, sex, weight, height, and interatrial septum dimensions. Patients with ASD > 20 mm (n = 9) had a higher ASD/device dimension ratio, both at echocardiography (p = 0.009) and at sizing balloon (p = 0.001), longer fluoroscopic time (p = 0.022), and higher incidence of device thrombosis (0.006). Right disc thrombosis was observed in three patients of the ASD > 20 mm group, always in the inferior portion of the right disc. On univariate analysis, ASD diameter at sizing balloon (OR 1.360; p = 0.036) was the only positive predictor of device thrombosis. CONCLUSIONS: Right disc thrombosis of the GCA device may be under-recognized at follow-up, hence deserving clinical attention, especially in those patients with larger ASD diameters.

Using a customized telescoped stent complex in the percutaneous treatment of a residual superior sinus venosus defect.

The management of superior sinus venosus defects (SVD) via transcatheter covered stent (CS) placement is becoming an acceptable alternative to open heart surgery. Though the medium-term success of this procedure has been described, residual shunting from damage to the covering of the implanted stents, use of stents which are too short and unanticipated shortening of stents may result in immediate or short-term procedural failure. In such cases, placement of a second CS may be required to address a residual defect. Preprocedural prediction of the length of stent required for residual leak treatment may not be as accurate as predicting the required stent length in a native defect, meaning that compassionate use applications to facilitate acquiring non-standard stent and balloon combinations may not be practical. We present a successful case of residual SVD closure using a novel sutured telescoping stent technique. Further collaboration with industry should encourage regulatory approval of longer CS, to mitigate the need for potentially unpredictable modifications such as this.

Iatrogenic atrial septal defects in structural heart interventions: Opening the Pandora's box.

In the modern era of structural heart interventions, the total number of transseptal procedures is growing exponentially, thus increasing the rate and need for management of iatrogenic atrial septal defects (iASDs). To date, there are no official guidelines on the assessment and management of iASDs, due to inconclusive evidence on whether patients benefit more from the percutaneous closure of iASD than from conservative management and vigorous follow-up. Despite the abundance of observational studies on iASDs, there is still a lack of randomized studies. Evidence so far show that percutaneous closure is no superior over conservative treatment in patients with iASDs, however, it has been demonstrated that patients with spontaneous closure of iASDs experience less heart failure (HF) hospitalizations. On the other hand, researchers have investigated the beneficial nature of interatrial shunt therapy in patients with HFpEF and, more recently, with HFrEF, due to the presumed hemodynamic benefits. Herein, we provide an updated review of relevant literature, focusing on iASD persistence rates, predicting factors for their persistence, and clinical outcomes of iASD persistence, to summarize available evidence and discuss future directions in the field.

Complications and Efficacies of Surgical Versus Transcatheter Closure for Pediatric Ostium Secundum Atrial Septal Defect: A Meta-Analysis.

INTRODUCTION: The optimal approach for pediatric ostium secundum atrial septal defect (ASD) closure remains uncertain. This study aims to assess complications and efficacies of surgical and transcatheter closures. METHODS: Systematic search in Medline, Cochrane, and EMBASE databases identified cohort studies until July 2023. Complications, length of hospital stay, and efficacy outcomes were evaluated. Subgroup analyses considered ethnicity, ASD size, age, and rim deficiency involvement. RESULTS: Fourteen cohort studies involving 9695 patients were comprehensively analyzed. Regarding complications, the pediatric patients in the surgery group exhibited higher occurrences of cardiac arrhythmia (odds ratio [OR]: 1.87, 95% confidence interval [CI]: 1.22-2.87, p=0.004), pericardial effusion (OR: 14.80, 95% CI: 6.97-31.43, p<0.00001), and pulmonary complications (OR: 2.58, 95% CI: 1.73-3.85, p<0.00001) compared with those in the transcatheter group. However, no significant difference in fever incidence was observed (OR: 2.57, 95% CI: 0.90-7.34, p=0.08). Furthermore, length of hospital stay was notably shorter in the pediatric transcatheter group (mean difference [MD]: 4.00, 95% CI: 1.71-6.29, p=0.0006). Regarding efficacies, both groups demonstrated similar rates of successful closure (OR: 1.97, 95% CI: 0.56-6.92, p=0.29) and residual shunting (OR: 0.55, 95% CI: 0.17-1.77, p=0.31) in the pediatric cohort. Subgroup analyses revealed that surgical residual shunting was notably lower in the European pediatric population (OR: 0.18, 95% CI: 0.07-0.45, p=0.0002), in cases with ASD size exceeding 15 mm (OR: 0.19, 95% CI: 0.08-0.49, p=0.0006), and in pediatric patients younger than 8 years (OR: 0.33, 95% CI: 0.12-0.92, p=0.03). Interestingly, residual shunting involving complex ASD with rim deficiency was more pronounced in the surgery group (OR: 2.66, 95% CI: 1.33-5.32, p=0.006). CONCLUSIONS: Both surgical and transcatheter closures are equally effective, with transcatheter closure showing significantly fewer complications. CLINICAL IMPACT: This meta-analysis offers pivotal insights for clinicians grappling with the optimal approach to pediatric ostium secundum ASD closure. The observed higher incidence of cardiac arrhythmias, pericardial effusions, and pulmonary complications in surgical closures underscores the challenges associated with this modality. In contrast, transcatheter closure, with its comparable efficacy and shorter hospital stays, emerges as an appealing and less invasive alternative. These findings equip clinicians with evidence to make informed decisions, optimizing patient outcomes. Subgroup analyses further refine recommendations, emphasizing tailored considerations for European pediatric patients, larger ASDs, and those under 8 years old, ultimately fostering personalized and improved care strategies.

Transcatheter Closure of Atrial Septal Defects with Absent Aortic Rim and the Predictors of Right Atrial Reverse Remodeling: 5 Years Experience in China.

INTRODUCTION: Atrial septal defect (ASD) is one of the most common congenital heart malformations. Although not recommended, a significant proportion of patients with aortic root defects receive ASD closure, some of whom have improved right ventricular function. The study aimed to investigate the safety of interventional therapy in ASD patients with complete aortic rim deficiency and explore the predictors of right atrial (RA) non-reverse remodeling. METHODS: 1,011 patients with ASD who underwent transcatheter closure in the Department of Cardiology, Zhongshan Hospital, affiliated to Fudan University from June 2017 to June 2023 were enrolled in the study. They were divided into a complete aortic rim deficiency group and without absent aortic rim group. Furthermore, patients who had an enlarged RA in the absent aortic rim group were divided into two subgroups according to whether their RA remodeling was reversed post-procedure. Multivariate logistic regression was used to determine the predictors of RA reverse remodeling. RESULTS: During the 1-year follow-up, no major operative complications occurred in all patients with the absence of an aortic rim and a normal edge. After the operation, the right heart remodeling was significantly reversed, multivariate logistic regression analysis was performed, and it was found that no coronary heart disease before an operation, lower plasma creatinine level, and larger RA and RV dimensions were the predictive factors for the reverse of RA remodeling after treatment. CONCLUSION: Transcatheter closure of ASD with complete aortic rim deficiency is safe and feasible. For patients without coronary heart disease, the lower the creatinine value and the lower the tricuspid regurgitation before an operation, the more improvement of RA remodeling after the operation.

Echocardiography-guided percutaneous closure of oval-shaped secundum atrial septal defects.

BACKGROUND: An atrial septal defect (ASD) is considered oval-shaped when its shortest diameter is less than 75% of the longest diameter. Research on percutaneous closure of oval-shaped ASDs is limited, with no known reports of non-fluoroscopic closure for this population. OBJECTIVE: To assess the effectiveness of non-fluoroscopic percutaneous closure for oval-shaped ASDs. METHODS: This single-center retrospective study evaluates patients undergoing non-fluoroscopic percutaneous closure of oval-shaped ASDs, defined by the shortest to longest diameter ratio < 0.75, a circular index of 1.33, or ultrasound visualization of an oval shape. Device size was chosen to be 0-4 mm larger than the defect's longest diameter, based on transthoracic and transesophageal ultrasound measurements. RESULTS: We identified 78 patients (33.3% children, 20.5% males) with a mean age of 27.4 ± 16.3 years and a mean weight of 46.8 ± 19.8 kg. The mean longest diameter and mean shortest diameter of ASDs were 23.3 ± 6.8 mm and 15.8 ± 5 mm, respectively. The mean ratio of the shortest to longest diameter was 0.7 ± 0.1. Percutaneous closure was not attempted in 7/78 (9%) patients. Three out of 71 (4.2%) procedures were fluoroscopy-guided upfront due to technical difficulties, and 5/71 (7%) were converted to fluoroscopy-guided closure. Overall procedural success rate was 98.6% (70/71) including 63/71 (88.7%) performed with zero fluoroscopy. Mean device size was 26.5 ± 7.1 mm. Mean procedural time was 45.3 ± 22.6 min. Eleven intraprocedural complications occurred including 6 arrhythmias, 3 pericardial effusions, and 2 device dislodgements. CONCLUSION: Transcatheter closure of oval-shaped ASD is safe and feasible. Echocardiography is adequate for adequate operative guidance.

The association of right ventricular-pulmonary arterial coupling and pulmonary vascular resistance in adult patients with uncorrected atrial septal defect.

BACKGROUND: Atrial septal defects (ASD) are the most common type of adult congenital heart disease (ACHD) associated with a high risk developing of pulmonary arterial hypertension (PAH). ASD closure is not recommended in patients with PAH and Pulmonary Vascular Resistance (PVR) ≥ 5 Wood Unit (WU). Noninvasive methods have been proposed to measure PVR; however, their accuracy remains low. Right Ventricle (RV) - Pulmonary Artery (PA) coupling is defined as the ability of the RV to adapt to high-resistance conditions. Tricuspid Annular Plane Systolic Excursion (TAPSE)/estimated pulmonary artery systolic pressure (ePASP) calculation using echocardiography is a noninvasive technique that has been proposed as a surrogate equation to evaluate RV-PA coupling. Currently, no research has demonstrated a relationship between RV-PA coupling and PVR in patients with ASD. METHODS: The study participants were consecutive eligible patients with ASD who underwent right heart catheterization (RHC) and echocardiography at Hasan Sadikin General Hospital, Bandung. Both the procedures were performed on the same day. RV-PA Coupling, defined as TAPSE/ePASP > 0.31, was assessed using echocardiography. The PVR was calculated during RHC using the indirect Fick method. RESULTS: There were 58 patients with ASD underwent RHC and echocardiography. Among them, 18 had RV/PA Coupling and 40 had RV/PA Uncoupling. The PVR values were significantly different between the two groups (p = 0.000). Correlation test between TAPSE/ePASP with PVR showed moderate negative correlation (r= -0.502, p = 0.001). TAPSE/ePASP ≤ 0.34 is the cutoff point to predict PVR > 5 WU with sensitivity of 91.7% and specificity 63.6%. CONCLUSION: This study showed a moderate negative correlation between TAPSE/ePASP and PVR. TAPSE/ePASP ≤ 0.34 could predict PVR > 5 WU with good sensitivity.

Outcomes of Concomitant Cardiac Surgical Procedures Performed During Pediatric Lung Transplantation in the United States.

Data on concomitant cardiac surgery (CCS) performed during pediatric lung transplantation (LTx) is limited. Therefore, we conducted a multi-institutional analysis to identify the incidence and outcomes of CCS in pediatric (< 18 years) LTx recipients by merging data (2004-2023) from the United Network for Organ Sharing (UNOS) and Pediatric Health Information System (PHIS) databases. Of the total of 596 pediatric LTx recipients, 87 (15%) underwent CCS. The majority of these cardiac surgeries were atrial septal defect (ASD) closure (90%) followed by aortic arch/descending aortic repair (3%), atrial repair (3%), ventricular septal defect closure (2%), patent ductus arteriosus ligation (2%), and tricuspid valve repair (2%). The median age at LTx was 3 years (IQR: 0-12). Pulmonary hypertension (PHT) was the predominant indication for LTx (54%). Survival to discharge was 94% and 5-years survival was 64%. Our findings indicate CCS in children undergoing LTx has acceptable outcomes.

Three-dimensional transesophageal echocardiography measurements of ASD sizing parameters in comparison to balloon sizing method in percutaneous ASD closure.

BACKGROUND: Balloon sizing (BS) has been used for device size selection in percutaneous atrial septal defect (ASD) closure. Due to its limitations, alternative imaging techniques like three-dimensional transesophageal echocardiography (3D-TEE) are valuable for guiding ASD device size selection during ASD closure procedures. The purpose of this study was to compare ASD sizing using measurements obtained from 3D-TEE to those utilizing the standard balloon sizing method. METHODS: We identified 53 patients with single secundum type ASD without PFO who underwent percutaneous closure at the Tehran Heart Center between 2019 and 2022. Balloon sizing was performed in all patients with the stop-flow technique, and the choice of device size was determined based on the sizing derived from BS. 3D-TEE imaging was performed before the intervention, and the ASD shape and quality of ASD rims were assessed. RESULTS: Among the 53 patients who underwent single ASD device closure, multiple 3D TEE measurements significantly correlated with balloon sizing results. This included defect area, perimeter, and diameter obtained from 3D-TEE images multi-planar reconstruction. ASD perimeter detected by 3D TEE had the best correlation with BS results. When divided by the shape of ASD, there was no significant difference between our 3D-images data and BS in round or oval-shaped ASDs. CONCLUSION: The 3D-TEE study is reliable for assessing ASD configurational characteristics in percutaneous device closure candidates. 3D-TEE has the potential to accurately determine the appropriate device size and reduce complications, costs, and procedural duration. Further research is needed to validate these findings and establish the role of 3D-TEE measurements in guiding the best treatment decisions for ASD closure.

A comparison of intracardiac echocardiography and transesophageal echocardiography for guiding device closure of ostium secundum atrial septal defect: A 15-year experience.

BACKGROUND AND AIM: Our aim was to evaluate the fluoroscopy time (FT), procedure time (PT) safety and efficacy when using intracardiac echocardiography (ICE) in comparison to transesophageal echocardiography (TEE) guidance for transcatheter closure of Ostium Secundum Atrial Septal Defect (OS-ASD). METHOD: Ninety patients (n = 90) diagnosed with OS-ASD underwent transcatheter closure between March 2006 and October 2021. Fifty-seven patients were treated under ICE guidance, while 33 patients were treated under TEE guidance. RESULTS: Mean age was 43 ± 15 years and 42 ± 10 years in the ICE and TEE groups, respectively. The majority of patients had a centrally placed defect. Median FT was 8.40 min versus 11.70 min (p < .001) in the ICE group compared to the TEE group, respectively. Median PT was 43 min versus 94 min (p < .001) in the ICE group compared to the TEE group, respectively. Both ICE and TEE provided high quality images. All interventions were completed successfully, except for one patient in the ICE group who experienced a device migration, the development of atrial tachycardia in one patient and atrial fibrillation in two patients in the ICE group which spontaneously cardioverted. There were no other complications. CONCLUSION: This study on a consistent cohort of patients with OS-ASD undergoing percutaneous closure suggests that use of ICE is safe and efficacious. Compared to TEE, ICE demonstrated significantly shorter FT and PT, decreasing the entire duration of the procedure and x-ray exposure. No relevant differences were observed in terms of success rate and complications.

A rare case of inferior sinus venosus atrial septal defect and concomitant hypoplasia of the posterior mitral valve leaflet.

Inferior sinus venosus atrial septal defect (SVASD) is the rarest form of the atrial septal defect (ASD) and can sometimes go unnoticed. Although this defect can be associated with other congenital anomalies, its association with hypoplasia of the posterior mitral leaflet is extremely rare. In this case, we present a woman with a history of surgery for an ostium secundum ASD who exhibited persistent right heart chamber dilation. Echocardiography revealed hypoplasia of the posterior mitral leaflet, and cardiac magnetic resonance (CMR) imaging confirmed the presence of a previously undetected inferior sinus venosus ASD.

Delayed diagnosis of Loeys-Dietz syndrome revealed through atrial septal defect with pulmonary artery dilation.

Loeys-Dietz syndrome (LDS) is an autosomal-dominant connective tissue disorder associated with mutations in the transforming growth factor ß receptor. It is characterized by distinctive craniofacial changes, skeletal features, and cardiovascular complications. We present a case of a 24-year-old male with development delay and a one-year history of progressively worsening dyspnea on moderate exertion and orthopnea. Echocardiography revealed right atrial and right ventricle dilation, right ventricle hypertrophy, atrial septal defect, and aneurysmal dilation of the pulmonary artery trunk. This case underscores the importance of early detection and comprehensive imaging in patients suspected of having LDS, particularly considering the potential for atypical vascular manifestations.

Quantitative evaluation of right ventricular myocardial function changes in patients with atrial septal defect before and after occlusion by noninvasive right ventricular pressure-strain loop.

OBJECTIVE: The noninvasive right ventricular pressure-strain loop (PSL) represents a novel method for the quantitative assessment of right ventricular myocardial function. Given that atrial septal defect (ASD) is a prevalent congenital heart anomaly associated with right ventricular volume overload, this study aimed to quantitatively assess the myocardial function of the right ventricle in ASD patients pre- and post-occlusion by noninvasive right ventricular PSL. METHODS: This study included 36 patients diagnosed with secundum ASD group and 30 healthy adults (control group). We compared conventional right ventricular echocardiographic parameters, right ventricular strain, and myocardial work in the ASD group before occlusion, two days post-occlusion, and three months post-occlusion, with those in the control group. RESULTS: Prior to and two days following occlusion, the ASD group exhibited higher right ventricular global work index (RVGWI), right ventricular global wasted work (RVGWW), and right ventricular global constructive work (RVGCW) compared to the control group (P < .05). Within the ASD group, post-occlusion, RVGWI, RVGCW, and RVGWW values were significantly reduced compared to pre-occlusion values (P < .001). Furthermore, RVGWI and RVGCW showed a significant decrease three months after occlusion compared to two days post-occlusion (P < .05). Multivariate regression analysis identified ASD diameter and pulmonary artery systolic pressure (PASP) as independent predictors of RVGWI (ß = .405, P < .001; ß = 2.307, P = .037) and RVGCW(ß = .350, P<.001; ß = 1.967, P = .023). CONCLUSIONS: The noninvasive right ventricular PSL effectively demonstrates the alterations in right ventricular myocardial function in ASD patients, pre- and post-occlusion. The metrics of right ventricular myocardial work (RVMW) offer a novel indicator for evaluating right ventricular myocardial function in these patients. Moreover, ASD diameter and PASP emerge as independent determinants of RVGWI and RVGCW.

Human Genetics of Tricuspid Atresia and Univentricular Heart.

Tricuspid atresia (TA) is a rare congenital heart condition that presents with a complete absence of the right atrioventricular valve. Because of the rarity of familial and/or isolated cases of TA, little is known about the potential genetic abnormalities contributing to this condition. Potential responsible chromosomal abnormalities were identified in exploratory studies and include deletions in 22q11, 4q31, 8p23, and 3p as well as trisomies 13 and 18. In parallel, potential culprit genes include the ZFPM2, HEY2, NFATC1, NKX2-5, MYH6, and KLF13 genes. The aim of this chapter is to expose the genetic components that are potentially involved in the pathogenesis of TA in humans. The large variability in phenotypes and genotypes among cases of TA suggests a genetic network that involves many components yet to be unraveled.

Molecular Pathways and Animal Models of Atrial Septal Defect.

The relative simplicity of the clinical presentation and management of an atrial septal defect belies the complexity of the developmental pathogenesis. Here, we describe the anatomic development of the atrial septum and the venous return to the atrial chambers. Experimental models suggest how mutations and naturally occurring genetic variation could affect developmental steps to cause a defect within the oval fossa, the so-called secundum defect, or other interatrial communications, such as the sinus venosus defect or ostium primum defect.

Human Genetics of Atrial Septal Defect.

Although atrial septal defects (ASD) can be subdivided based on their anatomical location, an essential aspect of human genetics and genetic counseling is distinguishing between isolated and familiar cases without extracardiac features and syndromic cases with the co-occurrence of extracardiac abnormalities, such as developmental delay. Isolated or familial cases tend to show genetic alterations in genes related to important cardiac transcription factors and genes encoding for sarcomeric proteins. By contrast, the spectrum of genes with genetic alterations observed in syndromic cases is diverse. Currently, it points to different pathways and gene networks relevant to the dysregulation of cardiomyogenesis and ASD pathogenesis. Therefore, this chapter reflects the current knowledge and highlights stable associations observed in human genetics studies. It gives an overview of the different types of genetic alterations in these subtypes, including common associations based on genome-wide association studies (GWAS), and it highlights the most frequently observed syndromes associated with ASD pathogenesis.