The parasternal long axis view is useful for characterizing the mechanism of subaortic stenosis. The fibromuscular ridge is often discrete, but can be circumferential with attachments to the mitral valve. In some cases, the subaortic stenosis can be tunnel-like with a large portion of the left ventricular outflow tract appearing narrowed and tubular. The distance from the fibrous ridge to the aortic valve should be measured and an interrogation for attachments between the ridge and the aortic valve should take place as these are important factors to assess prior to surgical repair. Color aliasing by Dopper interrogaton will reveal the level where obstruction begins and will detect aortic valve reguritaiton, which is commonly associated with a subaortic membane. This view will also be useful to assess for the presence of a ventricuar septal defect and abnormalities of the mitral valve.