Emergency Pulmonary Artery-to-Systemic Artery Shunt to Break the Positive Feedback Loop of a Pulmonary Hypertensive Crisis after Neonatal Coarctation Repair.

A 2.5-kg neonate with coarctation of the aorta and a small left ventricle experienced a severe pulmonary hypertensive crisis. An emergency pulmonary artery-to-systemic artery shunt was placed to break the positive feedback loop caused by pulmonary hypertension and functional mitral stenosis. This shunt provided immediate relief of suprasystemic pulmonary hypertension and the resultant low cardiac output.