Introduction

Isolated right ventricular outflow tract obstruction (RVOTO) consists of a broad spectrum of anatomic lesions ranging from mild valvar pulmonary stenosis (PS) to pulmonary atresia (PA) with associated right-sided cardiac defects.

The "morphologically right ventricle" is a ventricle with the following characteristics, regardless of its anatomic position in the body:

• the ventricular septal surface is coarsely trabeculated,
• the inlet (atrioventricular) valve is of tricuspid morphology and has chordal attachments to the ventricular septal surface (the inlet atrioventricular valve of the right ventricle is septophillic).

Specific lesions discussed in this chapter include:

• Pulmonary atresia with intact ventricular septum (PA/IVS)
• Neonatal critical PS
• Valvar PS beyond the neonatal period
• Isolated supravalvar pulmonary stenosis
• Isolated subvalvar pulmonary stenosis
• Peripheral pulmonary artery stenosis