Electrical disorders in atrial septal defect: genetics and heritability

Genetic Insights into Congenital Cardiac Septal Defects-A Narrative Review

Congenital heart diseases (CHDs) are a group of complex diseases characterized by structural and functional malformations during development in the human heart; they represent an important problem for public health worldwide. Within these malformations, septal defects such as ventricular (VSD) and atrial septal defects (ASD) are the most common forms of CHDs. Studies have reported that CHDs are the result of genetic and environmental factors. Here, we review and summarize the role of genetics involved in cardiogenesis and congenital cardiac septal defects. Moreover, treatment regarding these congenital cardiac septal defects is also addressed.

Selective his bundle pacing eliminates crochetage sign: A case report

BACKGROUND

Crochetage sign is a specific electrocardiographic manifestation of ostium secundum atrial septal defects (ASDs), which is associated with the severity of the left-to-right shunt. Herein, we reported a case of selective his bundle pacing (S-HBP) that eliminated crochetage sign in a patient with ostium secundum ASD.

CASE SUMMARY

A 77-year-old man was admitted with a 2-year history of chest tightness and shortness of breath. Transthoracic echocardiography revealed an ostium secundum ASD. Twelve-lead electrocardiogram revealed atrial fibrillation with a prolonged relative risk interval, incomplete right bundle branch block, and crochetage sign. The patient was diagnosed with an ostium secundum ASD, atrial fibrillation with a second-degree atrioventricular block, and heart failure. The patient was treated with selective his bundle pacemaker implantation. After the procedure, crochetage sign disappeared during his bundle pacing on the electrocardiogram.

CONCLUSION

S-HBP eliminated crochetage sign on electrocardiogram. Crochetage sign may be a manifestation of a conduction system disorder.

Central Tetrapolydactyly With Atrial Septal Defect and Facial Nerve Palsy in a 15-Month-Old Female Child

Polydactyly, which is the presence of an extra appendage on the hand or the foot, is a common congenital anomaly encountered in children. It may be an isolated finding or found in conjunction with other congenital anomalies and syndromes. Polydactyly can occur in the hands or the feet. In the hand, it may occur as radial polydactyly (pre-axial polydactyly) or ulnar polydactyly (post-axial polydactyly (PAP)). Depending upon the side of occurrence, it may be medial, that is, toward the little finger (called ulnar polydactyly) or lateral, that is, toward the thumb (called radial polydactyly). On the feet, the extra digit can either be present on the side of the great toe (called tibial polydactyly) or on the side of the little toe (called fibular polydactyly). In both the upper and the lower limbs, affection of the central three digits is called central polydactyly. Central tetrapolydactyly, which is the presence of an extra appendage on all four limbs, is much more rarely encountered. This case report describes a 15-month-old female child who presented with findings of six digits on all four limbs and deviation of the left angle of mouth since birth. Her echocardiography showed a large atrial septal defect measuring 7 mm, with a left-to-right shunt. This is the first such case reported from all over the world from a tertiary care hospital with the aforementioned findings. Polydactyly, a very common congenital anomaly, should not be ignored in pediatric settings. It is important to diagnose associated features such as congenital heart diseases (CHDs), genitourinary abnormalities, and orofacial abnormalities to facilitate timely surgical correction and help improve the quality of life of those affected.

Congenital heart diseases (CHDs) and forensic investigations: Searching for the cause of death

Congenital Heart Diseases (CHDs) are a group of structural abnormalities or defects of the heart that are present at birth. CHDs could be connected to sudden death (SD), defined by the WHO (World Health Organization) as "death occurring within 24 h after the onset of the symptoms" in an apparently "healthy" subject. These conditions can range from relatively mild defects to severe, life-threatening anomalies. The prevalence of CHDs varies across populations, but they affect millions of individuals worldwide. This article aims to discuss the post-mortem investigation of death related to CHDs, exploring the forensic approach, current methodologies, challenges, and potential advancements in this challenging field. A further goal of this article is to provide a guide for understanding these complex diseases, highlighting the pivotal role of autopsy, histopathology, and genetic investigations in defining the cause of death, and providing evidence about the translational use of autopsy reports. Forensic investigations play a crucial role in understanding the complexities of CHDs and determining the cause of death accurately. Through collaboration between medical professionals and forensic experts, meticulous examinations, and analysis of evidence, valuable insights can be gained. These insights not only provide closure to the families affected but also contribute to the prevention of future tragedies.

Experience with the largest custom-made 48 mm fenestrated atrial septal occluder device and its 4-year follow-up

Atrial septal defects (ASDs) measuring <38 mm are referred for transcatheter closure. Availability of larger devices up to 46 mm extended the inclusion criteria. An elderly hypertensive male with a 44 mm secundum ASD and coexistent sick sinus syndrome and atrioventricular (AV) nodal block presented with syncope. Balloon interrogation unmasked restrictive left ventricular (LV) physiology. After AV synchronous pacing, balloon-assisted deployment of a custom fenestrated 48 mm Figulla septal occluder (Occlutech Inc., Schaffhausen, Switzerland) prevented a rise of LV end-diastolic pressures beyond 12 mmHg. Echocardiogram and computed tomography after 4 years confirmed a patent fenestration and favorable remodeling. This report of the clinical use of the largest ASD device demonstrated the feasibility of closure of extremely large defects despite a restrictive LV.

Functional analysis of two novel TBX5 variants present in individuals with Holt-Oram syndrome with different clinical manifestations

Holt-Oram syndrome (HOS) is a rare disorder characterized by cardiac and upper-limb defects. Pathogenic variants in TBX5-a gene encoding a transcription factor important for heart and skeletal development-are the only known cause of HOS. Here, we present the identification and functional analysis of two novel TBX5 pathogenic variants found in two individuals with HOS presenting distinct phenotypes. The individual with the c.905delA variant has a severe cardiac phenotype but mild skeletal defects, unlike the individual with the c.246_249delGATG variant who has no cardiac problems but severe upper limbs malformations, including phocomelia. Both frameshift variants, c.246_249delGATG and c.905delA, generate mRNAs harbouring premature stop codons which, if not degraded by nonsense mediated decay, will lead to the production of shorter TBX5 proteins, p.Gln302Argfs*92 and p.Met83Phefs*6, respectively. Immunocytochemistry results suggest that both mutated proteins are produced and furthermore, like the wild-type protein, p.Gln302Argfs*92 mutant appears to be mainly localized in the nucleus, in contrast with p.Met83Phefs*6 mutant that displays a higher level of cytoplasmic localization. In addition, luciferase activity analysis revealed that none of the TBX5 mutants are capable of transactivating the NPPA promoter. In conclusion, our results provide evidence that both pathogenic variants cause a severe TBX5 loss-of-function, dramatically reducing its biological activity. The absence of cardiac problems in the individual with the p.Met83Phefs*6 variant supports the existence of other mechanisms/genes underlying the pathogenesis of HOS and/or the existence of an age-related delay in the development of a more serious cardiac phenotype. Further studies are required to understand the differential effects observed in the phenotypes of both individuals.

Association between congenital heart disease and NKX2.5 gene polymorphisms: systematic review and meta-analysis

Aim: To analyze the association of NKX2.5 gene with congenital heart disease (CHD), and to determine if the variants rs703752, rs3729753 and rs2277923 increase the risk for developing CHD. Materials & methods: PubMed, EBSCO and Web of Science databases were screened to identify eligible studies. Through a comprehensive meta-analysis software, the association between NKX2.5 gene variants and susceptibility of CHD was calculated by pooled odd ratio (ORs) and 95% CI. Results: We observed that the allelic model of rs703752 and rs2277923 increased the risk in the overall population: OR = 1.24; 95% CI: 1.00-1.55; Z p-value = 0.049; OR = 1.18; 95% CI: 0.01-1.37; Z p-value = 0.036; respectively. Conclusion: Our results suggested that the rs703752 and rs2277923 polymorphisms of the NKX2.5 gene are associated with CHD.