Percutaneous balloon valvuloplasty of the pulmonary valve: role of right to left shunting through a patent foramen ovale.

Percutaneous balloon valvuloplasty was performed on a patient with pulmonary stenosis. Right to left shunting through a patent foramen ovale during balloon inflation was documented by contrast two-dimensional echocardiography. Right and left ventricular pressures recorded during balloon inflation showed a decrease in left ventricular end-diastolic pressure and equilibration with right ventricular end-diastolic pressure. Systemic hypotension was minimal during balloon inflation, possibly due to persistent filling of the left ventricle via the patent foramen ovale. Persistent right ventricular systolic hypertension immediately after valvuloplasty may have been due to infundibular narrowing and resolved on restudy 2 weeks later.