Discrete subaortic stenosis in adults: increased prevalence and slow rate of progression of the obstruction and aortic regurgitation

ACC/AHA 2008 Guidelines for the Management of Adults With Congenital Heart Disease

“…The prevalence of discrete SubAS among ACHD patients has been reported to be 6.5%, 352 with a male preponderance of 2:1. In some cases, such as Shones syndrome, SubAS may be familial.…”

“…The dominant feature may be obstruction or AR. 352,354,355 AR occurs in more than 50% of those with SubAS. Once the peak Doppler gradient across the SubAS is more than 30 mm Hg, and if the membrane is immediately adjacent to the aortic valve or there is extension of the membrane onto the mitral valve, LVOT obstruction is likely to be progressive.…”

Incremental utility of Live/Real time three-dimensional transesophageal echocardiography in diagnosis of a unique type of subaortic membrane: a case report

“…This condition is either isolated or concurs with The prevalence of discrete subvalvular membrane in adults has been reported as 6.5% by Oliver et al (2). Ventricular septal defect (14.9%), aortic coarctation (12.7%) and bicuspid aortic valve (2.2%) may accompany this anomaly (2).…”

8th Decades Presentation of Subaortic Fibrous Membrane with Left Ventricular Outfow Tract Obstruction

“…DSS causes morphologic abnormalities at LVOT. This status includes increased aorto-mitral fibrous distance, arised aorto-septal angle, malalignment ventricular septal defect and increased turbulence (10). Then septal shear stress generate proliferative reaction at endocardium and development of subaortic membrane (3,6,7) At the final producing of left ventricular hypertrophy and aortic regurgitation are inevitable (6,8).…”

“…Timing for surgical treatment is controversial (6,8). But if left ventricular hypertrophy and AR started surgery must be the choice (10). At rapid progression on LVOT obstruction early resection of subaortic membrane with surgery may be recommended (4).…”