Phentolamine improves clinical outcome after balloon valvoplasty in neonates with severe pulmonary stenosis.

Two neonates with severe pulmonary stenosis deteriorated immediately after successful balloon valvoplasty as a result of increased infundibular obstruction. They were treated with beta-adrenoceptor blockers and intravascular expansion with limited success. Phentolamine was then given, resulting in dramatic improvement. The children could be weaned from the ventilator within hours of starting this new therapeutic modality.