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Severe Early-Onset Pulmonary Hypertension in a Six-Month-Old With Down Syndrome and Isolated Secundum Atrial Septal
Fatima Abeer1, Aasim Ayaz Wani2, Bisma Javid1
1Department of Internal Medicine, Government Medical College, Srinagar, Srinagar, IND.
Insights
Infants with Down syndrome (trisomy 21) are at high risk for severe pulmonary arterial hypertension (PAH). Even mild atrial septal defects (ASDs) can rapidly worsen, requiring early intervention.
Area of Science:
- Pediatrics
- Cardiology
- Genetics
Background:
- Infants with Down syndrome (trisomy 21) frequently have congenital heart defects and immune issues, raising the risk of early pulmonary arterial hypertension (PAH).
- Secundum atrial septal defects (ASDs), usually mild in non-syndromic infants, can progress rapidly in those with trisomy 21.
Observation:
- A six-month-old infant with trisomy 21 presented with severe PAH due to a rapidly enlarging secundum ASD.
- The infant had a history of neonatal sepsis, recurrent infections, failure to thrive, and subclinical hypothyroidism.
- Echocardiography showed significant ASD enlargement (6mm to 10mm) and a large left-to-right shunt (Qp:Qs >1.5:1).
Findings:
- Management with antibiotics, sildenafil, oxygen, and nutritional support stabilized the infant.
- Pulmonary vasodilator therapy served as a crucial bridge to deferred surgical ASD closure.
Implications:
- This case highlights the increased susceptibility of infants with Down syndrome to severe PAH, even from seemingly minor ASDs.
- Early cardiac assessment, prompt treatment, and multidisciplinary care are vital for preventing irreversible pulmonary vascular disease in this population.
Abstract:
Infants with Down syndrome (trisomy 21) commonly present with congenital heart defects and immune dysregulation, significantly increasing the risk of early-onset pulmonary arterial hypertension (PAH). Although secundum atrial septal defects (ASDs) are often considered hemodynamically mild in non-syndromic children, they can progress aggressively in the presence of trisomy 21. We describe a six-month-old male infant with karyotype-confirmed trisomy 21 who developed severe PAH secondary to a rapidly enlarging secundum ASD - a highly atypical presentation for an isolated lesion. The infant presented with fever, respiratory distress, vomiting, and diarrhea, alongside a clinical history of neonatal sepsis, recurrent infections, failure to thrive (weight below the 5th percentile), and subclinical hypothyroidism (TSH 8.12 μIU/mL). Echocardiography revealed that the ASD had enlarged from 6 mm at five months to 10 mm, creating a substantial left-to-right shunt (Qp:Qs >1.5:1). Management with IV ceftriaxone, sildenafil (2 mg twice daily), supplemental oxygen, and nutritional support stabilized the infant within five days (SpO₂ 93-94% on room air). He was discharged for deferred surgical ASD closure, highlighting the value of early pulmonary vasodilator therapy as a bridge to definitive repair. This case underscores the markedly increased susceptibility of infants with Down syndrome to severe PAH, even in the setting of a seemingly hemodynamically insignificant ASD. Early cardiac evaluation, prompt intervention, and multidisciplinary management are crucial to preventing irreversible pulmonary vascular disease in this high-risk population.
