What is pediatric PH

Pediatric PH shares a similar definition to adult PH. It is defined as a resting mean pulmonary artery pressure (mPAP) of greater than 25 mmHg beyond the first three months of life. There are however, key differences in the following disease aspects:

• Classification
• Etiology and symptoms
• Diagnosis
• Treatment

Classification

Although the classification of adult and pediatric PH is the same, it is uncertain whether this system is sufficient for use in children. One major reason for this is that pediatric PH is intrinsically linked to issues in lung growth and development and can often be attributed to impaired functional and structural adaptation of the pulmonary circulation during the transition from fetal to postnatal life. In addition, many more conditions have been associated with PH in children compared to adults.

Etiology and symptoms

The majority of pediatric cases are classified as idiopathic PAH (iPAH), heritable PAH, and PAH associated with congenital heart disease (APAH-CHD), marking a difference in the distribution of etiologies in the two populations. Due to non-specific symptoms, iPAH is usually diagnosed in its later stages. Infants with iPAH often present with poor appetite, failure to thrive, tachypnea, and irritability due to low cardiac output. Older children, on the other hand, have similar symptoms to adults including exercise intolerance and occasionally chest pain. Results from the TOPP-1 registry illustrated that near-syncope and syncope were more common in children with iPAH and familial PAH, whereas peripheral edema was more common in adults.