Congenital subaortic stenosis

In cases of subaortic stenosis, the aortic valve is mostly normal, showing a trilobal shape. In some cases, the leaflets are slightly thickened or have mild incomplete closure. A small number of patients may have dual valve aortic stenosis. The left ventricular myocardium exhibits highly concentric hypertrophy. Insufficient subendocardial blood supply can cause myocardial fibrosis. Sometimes the degree of ventricular septal myocardial hypertrophy is more significant than that of the posterior wall of the left ventricle, which is easily confused with obstructive hypertrophic cardiomyopathy. Sub-aortic fibrous stenosis is associated with other congenital cardiac vascular malformations in about one-third of cases. Common cases include ventricular septal defect, aortic arch interruption, open ductus arteriosus, tetralogy of Fallot, atrial septal defect, pulmonary stenosis, Right ventricular flow channel is narrow.