الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
The left ventricular outflow tract is a complex structure that includes the aortic valve, the sinuses of Valsalva and the subvalvular fibromuscular outflow from the left ventricle. Obstruction to the left ventricular outflow tract may be found at valvular, subvalvular, supravalvular or combined levels. The left ventricular outflow tract obstruction may be isolated or associated with other defects. The association of aortic stenosis with parachute mitral valve and coarctation of the aorta is known as the Shone syndrome.
Despite being one of the most common congenital cardiac abnormalities, the treatment of left ventricular outflow tract obstruction (LVOTO) remains a significant challenge. Taken as a group, children with LVOTO present across a wide morphologic spectrum of hypoplasia of left heart structures with variable hemodynamic manifestations which are based on the level and the severity of the obstruction, the related hypoplasia of the left ventricle and the mitral valve, and associated lesions such as ventricular septal defect and aortic arch hypoplasia. These factors influence the treatment strategies that can be applied to patients with LVOTO, and the particular surgical or catheter-based methods employed to achieve relief of the obstruction. Because of the wide array of morphologic lesions and physiologic manifestations, application of the currently available published data to guide decision making in the individual patients can be challenging.