What is the leading cause of discrete subaortic stenosis?

Discrete subaortic stenosis is primarily caused by the presence of a discrete subaortic membrane, which is a fibromuscular tissue that forms just below the aortic valve in the left ventricle outflow tract. This membrane can obstruct blood flow from the left ventricle to the aorta, leading to pressure gradients and potential complications such as left ventricular hypertrophy.

Understanding this condition involves recognizing that while other cardiac conditions such as pericarditis, atrial septal defect, and ventricular septal defect can impact heart function, they do not specifically cause discrete subaortic stenosis. The discrete subaortic membrane is functionally distinct and considered the direct anatomical abnormality responsible for this type of obstruction. Thus, identifying the discrete subaortic membrane as the leading cause is critical for effective diagnosis and management of patients presenting with this condition.