Table 1: Clinical classification of pulmonary arterial hypertension associated with congenital heart disease.

1. Eisenmenger syndrome 2. Left-to-right shunts 3. Pulmonary arterial hypertension (PAH) with coincidental congenital heart disease 4. Post-operative PAH
Includes all large intra and extra cardiac defects which begin as systemic
to pulmonary shunts and progress with time to severe elevation of pulmonary vascular resistance (PVR)
and to reversal (pulmonary to systemic) or bidirectional shunting; cyanosis, secondary erythrocytosis
and multiple organ involvement are usually present.
Include moderate to large defects; PVR is mildly to moderately increased systemic
to pulmonary shunting is still prevalent, whereas cyanosis is not a feature.
Marked elevation in PVR in the presence of small cardiac defects, which themselves
do not account for the development of elevated PVR; the clinical picture is very similar to
idiopathic PAH. To close the defects in contraindicated.
Congenital heart disease is repaired but PAH either persists immediately after surgery
or recurs/develops months or years after surgery in the absence of significant
postoperative hemodynamic lesions. The clinical phenotype is often aggressive.
Adapted from Simonneau G, Gatzoulis M, Adatia I, Celermajer D,
Denton C, et al. (2014) Updated clinical classification of pulmonary hypertension. J Am Coll Cardiol
63: 746. [28]