**5.3 Development of infundibular stenosis**

Development of infundibular stenosis, originally described by Gasul, occurs in 8% of VSDs. Some specific signs, namely, right aortic arch and increased angle of the right ventricular outflow tract that may influence the VSDs to undergo Gasul's transformation. Although the onset of infundibular stenosis ultimately needs surgery, it truly protects the pulmonary circulation and prevents development of PVOD.
