Pulmonary Hypertension in a 20-Week-Old Baby with Cardiomegaly
Yes, a 20-week-old baby with cardiomegaly can have pulmonary hypertension, as cardiomegaly is often associated with increased pulmonary arterial pressures in infants with chronic lung disease and other cardiac conditions. 1, 2
Pathophysiological Relationship Between Cardiomegaly and Pulmonary Hypertension
- Cardiomegaly in infants often reflects right ventricular enlargement secondary to increased pulmonary vascular resistance and pulmonary arterial pressure 1
- Infants with chronic lung disease of infancy (CLDI) commonly develop structural changes in pulmonary vasculature, including medial hypertrophy and abnormal extension of muscle to peripheral arteries, contributing to pulmonary hypertension 1
- Vascular endothelial growth factor expression is decreased in bronchopulmonary dysplasia (BPD), contributing to disordered vascular growth and pulmonary hypertension 1
- Cardiomegaly with right-sided cardiac enlargement is a common finding in children with pulmonary hypertension 3
Diagnostic Approach for Pulmonary Hypertension in Infants with Cardiomegaly
Clinical Assessment
- Clinical signs of pulmonary hypertension may be masked by respiratory disease, requiring high clinical suspicion 1
- Right ventricular heave, accentuated P2, or murmurs of tricuspid/pulmonary regurgitation may be difficult to detect due to hyperinflation and abnormal breath sounds 1
Non-invasive Testing
- Electrocardiogram can screen for changes consistent with cor pulmonale (right axis deviation, right atrial enlargement, right ventricular hypertrophy) 1
- Two-dimensional and Doppler echocardiography are essential to:
- Chest CT may reveal enlarged central pulmonary arteries, peripheral vasculopathy with tortuous vessels, and ground-glass centrilobular opacities 3
Invasive Assessment
- Cardiac catheterization is indicated when:
Common Causes of Pulmonary Hypertension with Cardiomegaly in Infants
- Bronchopulmonary dysplasia (BPD) - most common cause in premature infants 1
- Congenital diaphragmatic hernia (CDH) 1
- Congenital heart disease with left-to-right shunts 1
- Alveolar capillary dysplasia 1
- Lung hypoplasia 1
- Pulmonary vein abnormalities (e.g., Scimitar syndrome) 1, 4
- Down syndrome with associated cardiac defects 1
Management Considerations
- Supplemental oxygen therapy is the primary treatment to maintain oxygen saturation above 95% to keep pulmonary vascular resistance low 1
- Diuretics may be necessary if pulmonary edema is present 1
- Systemic hypertension, if present, should be treated as it can worsen cardiac function 1
- Advanced pulmonary vasodilator therapies should be considered experimental in infants and limited to research protocols 1
- Inhaled nitric oxide may be considered in severe cases as it is a selective pulmonary vasodilator 1
Monitoring and Follow-up
- Serial echocardiograms are useful to assess changes in pulmonary pressure with growth or therapy 1
- Regular monitoring of oxygen saturation during sleep is recommended for infants with chronic lung disease who have been taken off supplemental oxygen 1
- Longitudinal care in an interdisciplinary pediatric pulmonary hypertension program is recommended for infants at risk 1
Important Caveats
- Pulmonary hypertension in infants with cardiomegaly is associated with significant morbidity and mortality 1
- Non-selective vasodilators can cause systemic hypotension, tachycardia, and hypoxemia due to ventilation-perfusion mismatching 1
- Calcium channel-blocking agents can have negative inotropic effects and should be used cautiously 1
- Left ventricular hypertrophy may coexist with pulmonary hypertension and can contribute to pulmonary edema by elevating left atrial pressure 1