Patients with hypoplastic left heart syndrome and the first stage of palliation remain among the most tenuous patients with congenital heart disease with delicate physiology. In this article, we review the evolution of interventional management of this lesion as well as relevant physiology.

Critical pulmonary stenosis is a severe narrowing of the right ventricular outflow, leading to severe obstruction of blood flow from the right ventricle to the pulmonary artery often requiring the need for ductal patency to provide adequate pulmonary blood flow following birth. Diagnosis relies on echocardiography, with percutaneous balloon valvuloplasty as the preferred treatment and surgery for select cases. Long-term follow-up is essential due to risks of restenosis, pulmonary regurgitation, and reintervention, while advances in fetal therapy and valve replacement offer promising future improvements in outcomes.

Critical aortic stenosis (AS) in infants is a severe congenital heart defect requiring early intervention to prevent cardiogenic shock and death. Critical AS results from dysplastic valve morphology obstructing left ventricular outflow, presenting with ductal-dependent systemic circulation until intervention can be performed. Balloon aortic valvuloplasty (BAV) and surgical valvotomy are established treatments, with BAV increasingly favored for its less invasive profile. Despite high-reintervention rates, individualized treatment based on anatomy and institutional expertise remains a key to optimizing survival and long-term valve function.

Congenital heart block (CHB) is a rare fetal arrhythmia resulting from disruptions in the heart's electrical conduction system, often linked to maternal autoantibodies or congenital heart defects. This article examines the clinical presentation, pathophysiology, and diagnostic strategies of CHB, emphasizing advances in fetal echocardiography, maternal hydroxychloroquine prophylaxis, and multimodal therapies for refractory cases. Management options, including corticosteroids, intravenous immunoglobulin, and pacemaker implantation, are discussed alongside emerging technologies and pacing systems. By integrating current evidence, this article highlights the importance of early diagnosis, multidisciplinary care, and innovative interventions to improve outcomes for affected pregnancies and neonates.

Pulmonary atresia with intact ventricular septum is a cyanotic congenital heart lesion comprised of complete obstruction of the pulmonary outflow and varying degrees of right heart hypoplasia. There is a wide spectrum of disease from patients requiring minimally invasive transcatheter pulmonary valve perforation/balloon dilation as a neonate and having biventricular circulation, to patients requiring a ductal arterial stent or systemic-to-pulmonary-artery shunt as a neonate and undergoing single ventricle palliation, or even primary heart transplant. Factors determining these pathways include anatomic elements of the right ventricle, and presence, degree and severity of right ventricular-dependent coronary circulation.

Atrial tachycardia including focal atrial tachycardia and atrial flutter is seen in neonates with some frequency. The ability to correctly diagnose and treat the arrhythmias is an important skillset for anyone caring for newborn patients. Overall, the prognosis of atrial tachycardia in most neonates is excellent. In the case of atrial flutter, after termination of the presenting tachycardia, recurrence is rare. In focal atrial tachycardia, treatment is often indicated but can often be discontinued later in infancy or toddlerhood. In this article, we endeavor to guide clinicians caring for neonates by helping to differentiate mechanisms and counsel on therapy.

Total anomalous pulmonary venous connection is a rare congenital heart defect in which pulmonary veins drain into the systemic venous system rather than the left atrium, requiring an atrial communication for survival. Clinical presentation varies from severe neonatal cyanosis to milder symptoms later in infancy, with prognosis determined largely by pulmonary venous obstruction. Prenatal diagnosis is difficult but aided by targeted echocardiographic markers. Postnatal echocardiography is the diagnostic cornerstone, and individual vein size predicts outcomes. Surgical repair is the only definitive therapy; emergent surgery is indicated for obstruction, while stable non-obstructed cases undergo early planned repair. Modern techniques including primary sutureless repair have reduced postoperative pulmonary venous obstruction and improved survival.

Congenital heart defects (CHD) affect approximately 1 of every 100 live births in the United States. Advances in surgical and transcatheter interventions since the 1970s have markedly improved survival, with over 85% of affected infants now reaching adulthood. Clinical registries have enabled crucial insights into peri-operative and long-term outcomes. While survival has improved, patients with history of CHD interventions often face comorbidities, such as heart failure, arrhythmias, and neurodevelopmental challenges. Lifelong surveillance is essential, as most interventions do not constitute a cure but an important part of a life-long management of a chronic congenital condition.

New technology has ushered neonatology and cardiology providers into a new realm of transcatheter device closure of the patent ductus arteriosus within the premature neonate. Subsequently, there are lingering questions surrounding issues, such as patient candidacy, timing, procedure optimization, institutional, and referral-base practice changes, in management. Discussed here is the multidisciplinary and protocolized approach of a large volume, tertiary center with a wide referral catchment area, and it's now mid-term experience.

Pulmonary hypertension (PH) in the neonatal intensive care unit represents a complex and diverse spectrum of conditions, from transient persistent pulmonary hypertension of the newborn to chronic PH associated with bronchopulmonary dysplasia, congenital heart disease, and other conditions, and can cause significant morbidity and mortality. Proper classification, timely diagnosis using echocardiography and imaging, and tailored therapy are essential. A multidisciplinary approach is critical, particularly for infants with unclear or genetic causes. This article provides a thorough overview of the current classification schema of pulmonary hypertension, underlying pathophysiology, diagnostic work-up, treatment options, and long-term prognosis.

Congenital cytomegalovirus (CMV) infection is a major cause of sensorineural hearing loss and neurodevelopmental disabilities in childhood. Its diagnosis is dependent on performance of CMV testing at less than 21 days of age. Incorporation of CMV DNA polymerase chain reaction testing of the newborn dried blood spot would be ideal, but the sensitivity remains suboptimal. An infant's saliva sample placed in liquid transport media has shown excellent sensitivity. Although both targeted and universal CMV screenings are cost-effective, universal screening provides larger net savings and the greatest opportunity for directed care. In conclusion, the time for universal CMV screening is NOW!

Newborn hearing screening programs in the United States have evolved since first inception several decades ago. Screening has been effectively implemented across the country with coverage of upwards of 98% of children. However, less than half of children receive timely diagnosis and intervention. Serious barriers to effective early diagnosis hinder families from obtaining the crucial services children need to maximize language, cognitive, academic, and quality of life outcomes. Fortunately, effective strategies can be implemented to address barriers and ensure effective early hearing detection. Pediatricians and otolaryngologists are key providers who can facilitate timely diagnosis and management of congenital hearing loss.

Prenatal genetic diagnosis consists of fetal risk assessment utilizing screening options such as carrier screening for autosomal recessive conditions, fetal aneuploidy screening with serum-based, ultrasound-based, and cell-free DNA-based assessments, as well as diagnostic testing of direct fetal tissue prior to pregnancy with preimplantation genetic testing of embryos and during pregnancy with chorionic villus sampling of placental tissue and amniocentesis of fetal amniotic fluid. Utilizing these screening and testing options both prior to and during pregnancy can impact pregnancy decisions and management by identifying fetuses that may require specific postnatal management plans in the newborn period.

Pulse oximetry screening (POS) is a noninvasive tool for the detection of critical congenital heart defects (CCHD) that has moderate sensitivity and high specificity. It is readily accepted by parents and health care professional and has significantly reduced mortality from CCHD. This article discusses the impact of POS on CCHD screening, variations in algorithms used for implementation, practical aspects of POS programs, and challenges such as the effects of skin color and low detection rates for left-sided obstructive lesions, along with recent efforts to address these limitations by incorporating perfusion index and machine learning into POS algorithms.

Genetic testing that includes rapid genomic sequencing is increasingly being used in the neonate and has the potential to impact neonatal care and outcomes. Neonates with unexplained dysmorphic features or one or more congenital anomalies, unexplained dysfunction in one or more organ systems, or out of proportion clinical severity warrant genetic testing. Unless clinical features strongly suggest a specific chromosomal or single gene disorder, a broader genetic testing approach, ideally rapid exome or genome sequencing, is suggested. Neonatal providers should be aware of advances in genetic testing and collaborate with clinical geneticists and genetic counselors throughout the genetic testing process.

Congenital heart disease (CHD) is a common type of birth defect and a leading cause of infant and childhood mortality. Although recent advancements in genetic technologies have allowed for the discovery of new genomic variation associated with CHD, the prioritization and interpretation of variants for pathogenicity remain a challenge. Further, the underlying molecular genetic mechanisms for CHD remain incompletely defined. In this article, we summarize established genetic etiologies of CHD and highlight advances in knowledge of the underlying genetic architecture of CHD, along with challenges in genetic variation interpretation, the clinical implications of these genomic advances, and future directions.

Newborn screening (NBS) is utilized to identify genetic and other health issues in newborns to decrease morbidity, mortality, and the overall burden of disease to individuals and society by allowing early treatment, often before an infant would have signs or symptoms of a disease. Recently, utilization of genome sequencing (GS) has been proposed as an adjunct to GS for NBS (gNBS). Ongoing research studies focused on gNBS will provide crucial evidence on the appropriate integration of gNBS and traditional NBS.