Disturbances of the transitional circulation: spectrum of pulmonary hypertension and myocardial dysfunction.

Thirteen neonates presented with central cyanosis due to right-to-left shunting across the foramen ovale or the ductus arteriosus or both. In three infants shunting occurred secondary to pulmonary vascular obstruction, presumably related to pulmonary vasospasm (persistence of the fetal or transitional circulation). In ten neonates right-to-left shunting was associated with heart failure; seven of these neonates had systemic hypotension.