Abstract

Background: The classification of pulmonary stenosis (PS) severity based on the transpulmonary pressure gradient, which is affected by flow rate. 
Case Report: We report the first case of a pregnant patient with atrial septal defect (ASD) and pulmonary stenosis that was misclassified by conventional echocardiographic methods. Most importantly, three-dimensional transoesophageal echocardiographic assessment of pulmonary stenosis changed the entire treatment strategy. 
Conclusion: The planimetric calculation of the pulmonary valve (PV) opening area using three-dimensional transoesophageal echocardiographic may be helpful, especially in encounters with specialized conditions such as ASD and/or pregnancy, which can cause inaccurate recordings of the transvalvular peak gradient.