UNASSIGNED: Partial atrioventricular septal defects (pAVSDs) are mostly repaired in childhood; however, there are limited data describing these patients in adulthood.
UNASSIGNED: The objective of this study was to describe clinical course and associations with outcomes in adults with repaired pAVSDs.
UNASSIGNED: A retrospective review of adults (≥18 years) with pAVSDs repaired in childhood who presented to the Adult Congenital Heart Disease Clinic at our institution was conducted.
UNASSIGNED: Of 121 patients, the median age was 31 years (IQR: 22-43 years) and 71.9% were female. The median number of operations at the time of presentation was 1 (IQR: 1-2). Left atrioventricular valve (LAVV) replacement had been performed in 19.8% of patients. Among those with native LAVV, 41.2% had ≥ moderate regurgitation. Atrial arrhythmias were present in 34.7% and were associated with later age at repair (P = 0.02) and a high number of prior surgeries (P = 0.005). Estimated systolic pulmonary artery pressure >40 mmHg was seen in 19.8%. Over 4 (IQR: 1-12) years of follow-up, death occurred in 13 (10.7%) patients and reoperation was required in 39.7%. One-third had a LAVV prosthesis by the end of the study. Atrial fibrillation was independently associated with death or hospitalization on multivariable analysis.
UNASSIGNED: In this cohort of adults with pAVSDs repaired in childhood, atrial fibrillation was common at a young age and associated with worse outcomes. Thus, more studies are needed evaluating the cause of this arrhythmia burden and possible associated atrial myopathy. While many require surgery in adulthood, more information is needed regarding indications for and impacts of LAVV intervention as one-third had an LAVV prosthesis by the end of follow-up.

Defects of situs are associated with complex sets of congenital heart defects in which the normal concordance of asymmetric thoracic and abdominal organs is disturbed. The cellular and molecular mechanisms underlying the formation of the embryonic left-right axis have been investigated extensively in the past decade. This has led to the identification of mutations in at least 33 different genes in humans with heterotaxy and situs defects. Those mutations affect a broad range of molecular components, from transcription factors, signaling molecules, and chromatin modifiers to ciliary proteins. A substantial overlap of these genes is observed with genes associated with other congenital heart diseases such as tetralogy of Fallot and double-outlet right ventricle, d-transposition of the great arteries, and atrioventricular septal defects. In this chapter, we present the broad genetic heterogeneity of situs defects including recent human genomics efforts.

The development of a fully functional four-chambered heart is critically dependent on the correct formation of the structures that separate the atrial and ventricular chambers. Perturbation of this process typically results in defects that allow mixing of oxygenated and deoxygenated blood. Atrioventricular septal defects (AVSD) form a class of congenital heart malformations that are characterized by the presence of a primary atrial septal defect (pASD), a common atrioventricular valve (cAVV), and frequently also a ventricular septal defect (VSD). While AVSD were historically considered to result from failure of the endocardial atrioventricular cushions to properly develop and fuse, more recent studies have determined that inhibition of the development of other components of the atrioventricular mesenchymal complex can lead to AVSDs as well. The role of the dorsal mesenchymal protrusion (DMP) in AVSD pathogenesis has been well-documented in studies using animal models for AVSDs, and in addition, preliminary data suggest that the mesenchymal cap situated on the leading edge of the primary atrial septum may be involved in certain situations as well. In this chapter, we review what is currently known about the molecular mechanisms and animal models that are associated with the pathogenesis of AVSD.

Cardiac development is a fine-tuned process governed by complex transcriptional networks, in which transcription factors (TFs) interact with other regulatory layers. In this chapter, we introduce the core cardiac TFs including Gata, Hand, Nkx2, Mef2, Srf, and Tbx. These factors regulate each other\'s expression and can also act in a combinatorial manner on their downstream targets. Their disruption leads to various cardiac phenotypes in mice, and mutations in humans have been associated with congenital heart defects. In the second part of the chapter, we discuss different levels of regulation including cis-regulatory elements, chromatin structure, and microRNAs, which can interact with transcription factors, modulate their function, or are downstream targets. Finally, examples of disturbances of the cardiac regulatory network leading to congenital heart diseases in human are provided.

BACKGROUND: Controversial data exist about the impact of Down syndrome on outcomes after surgical repair of atrioventricular septal defect.
OBJECTIVE: (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.
METHODS: 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.
RESULTS: 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).
CONCLUSIONS: 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.

(1) Background: Artificial Intelligence (AI) is a modern tool with numerous applications in the medical field. The case series reported here aimed to investigate the diagnostic performance of the fetal intelligent navigation echocardiography (FINE) method applied for the first time in the prenatal identification of atrioventricular septal defects (AVSD). This congenital heart disease (CHD) is associated with extracardiac anomalies and chromosomal abnormalities. Therefore, an early diagnosis is essential to advise parents and make adequate treatment decisions. (2) Methods: Four fetuses diagnosed with AVSD via two-dimensional (2D) ultrasound examination in the second trimester were enrolled. In all cases, the parents chose to terminate the pregnancy. Since the diagnosis of AVSD with 2D ultrasound may be missed, one or more four-dimensional (4D) spatiotemporal image correlation (STIC) volume datasets were obtained from a four-chamber view. The manual navigation enabled by the software is time-consuming and highly operator-dependent. (3) Results: FINE was applied to these volumes and nine standard fetal echocardiographic views were generated and optimized automatically, using the assistance of the virtual intelligent sonographer (VIS). Here, 100% of the four-chamber views, and after the VISA System application the five-chamber views, of the diagnostic plane showed the atrioventricular septal defect and a common AV valve. The autopsies of the fetuses confirmed the ultrasound results. (4) Conclusions: By applying intelligent navigation technology to the STIC volume datasets, 100% of the AVSD diagnoses were detected.

BACKGROUND: There is an increasing number of adults with complete atrioventricular septal defects (cAVSD). However, data regarding older adults are lacking. The aim of this study is to analyze the outcome of adults with cAVSD over the age of 40 years.
METHODS: Patients with cAVSD who were ≥40 years of age at any point between 2005 until 2018 were included retrospectively. Data were retrieved from hospital records. The primary endpoint was a combination of death from any cause and unplanned hospitalizations due to cardiac reasons.
RESULTS: 43 patients (60.5% female, mean age 43.7 ± 6.0 years, genetic syndrome 58.1%) were included. At begin of follow-up, the majority of patients (n = 41, 95.3%) was in New York Heart Association (NYHA) class I or II. Out of the whole cohort 26 (60.5%) had undergone cardiac surgery. At baseline, at least one extracardiac comorbidity was present in 40 patients (93.0%). Median follow-up was 1.7 years (IQR 0.3-4.6). On univariate Cox analysis, NYHA class at begin of follow-up (hazard ratio: 1.96, CI 95%: 1.04-3.72, p < 0.05) was the only predictor for the primary endpoint.
CONCLUSIONS: Significant morbidity and mortality is present in cAVSD patients over the age of 40 years. NYHA class is predictive for a worse outcome.

We present an extremely rare combination of biventricular outflow obstruction associated with atrioventricular septal defects and patent ductus arteriosus (PDA). Almost all the other published cases, including ours, were associated with other congenital cardiac lesions other than biventricular outflow obstruction. Most cases ended with poor outcomes. Our patient was a 55-day-old term female infant. She was managed by successful aortic balloon valvuloplasty with successful early outcome.

BACKGROUND: The association of atrioventricular septal defect and transposition of the great arteries is very rare. As a rule, these patients have unbalanced ventricles. However, there have been no studies describing the results of single-ventricle palliation in these children.
METHODS: All children who underwent surgery with a diagnosis of atrioventricular septal defect and transposition of the great arteries were included in the study. Data were obtained from medical records.
RESULTS: A total of 38 patients with atrioventricular septal defect and transposition of the great arteries underwent single-ventricle palliation at the study institution between 1971 and 2016. The mean follow-up was 12.4 years (median: 14.6 years, range 2-43.3 years). Most children had unbalanced atrioventricular septal defect (94.7%, 36/38). Survival was 67.6% (95% confidence interval [CI]: 50.0-80.2%) at 10 years and 57.8% (95% CI: 38.0-73.4%) at 20 years. By 10 years, 58.6% (95% CI: 40.8-72.7%) had progressed to Fontan completion, while 32.5% (95% CI: 18.2-47.6%) had died. In patients achieving Fontan completion, 20-year event-free survival was 73.3% (95% CI: 34.8-91.3%), while 5.0% (95% CI: 0.4-20.5%) had undergone cardiac transplantation and 21.7% (95% CI: 3.2-50.8%) had undergone takedown of the Fontan circulation. Freedom from atrioventricular valve surgery was 57.0% (95% CI: 37.2-72.7%) at 10 and 20 years.
CONCLUSIONS: The association of atrioventricular septal defect and transposition of the great arteries is very rare, and most of these children have unbalanced ventricles. Single-ventricle palliation results in 25-year overall survival of 50%. However, in patients, who had Fontan completion, survival was 75% at 25 years after Fontan operation.

A meta-analysis is performed for a comparison of outcomes between the modified one-patch repair (MPR) and two-patch repair (TPR) for complete atrioventricular septal defects (CAVSD). Electronic databases, including PubMed, Scopus, Embase, and Cochrane Library were searched systematically for the literature which aimed mainly at comparing the therapeutic effects for CAVSD administrated by MPR and TPR. Corresponding data sets were extracted and two reviewers independently assessed the risks of bias. Meta-analysis was performed using Revman 5.3 and Stata 12.0. Fifteen studies meeting the inclusion criteria were included, involving 2076 subjects in total. It was observed that MPR was associated with shorter cardiopulmonary bypass (CPB) and aortic cross-clamp (ACC) times, as compared with TPR. However, no statistical differences were found in terms of size of ventricular septal defects (VSD), reoperation, mortality, implantation of permanent pacemakers, and length of ventilation, hospital and intensive care unit stay. As compared with TPR, MPR is superior in terms of ACC and CPB. However, with regard to reoperation, mortality, length of ventilation, ICU and hospital stay and permanent pacemakers implantation, no significant differences are found between these two procedures. MPR is likely to apply to younger infants with faster completion of surgery. Surgery is recommended between 3 and 6 months of age.