الفهرس Only 14 pages are availabe for public view
 |  | from | 127 |  |  |
| | | from | 127 | | |
Abstract
Left ventricular outflow tract obstruction includes a series of stenotic lesions starting in the anatomic left ventricular outflow tract (LVOT). Obstruction may be subvalvular, valvular, or supravalvular. These obstructions to forward flow may present alone or in concert,as in the frequent association of a bicuspid aortic valve with coarctation of the aorta. All of these lesions impose increased afterload on the left ventricle and, if severe and untreated,result in hypertrophy and eventual dilatation and failure of the left ventricle. It is imperative to consider all patients with LVOTO at a high risk for developing infective endocarditis, and one should always institute appropriate measures for prophylaxis. The present study is intended as a contemporary review of the causes, manifestations, treatments, and early outcomes surgical management of LVOTO.
Patients undergoing aortic valve replacement had an improvement in functional status, as well as systolic and diastolic left ventricular function, and a reduction in left ventricular mass index.
Left ventricular mass regression begins early after aortic valve replacement and left ventricle reaches their approximate final size within the first 6 months of surgery. This fact is due to reduction of transvalvular gradients and left ventricular wall stress.
Best aortic valve in the pediatric age group is the native one, provided it can function acceptably. However, in cases where conservative surgical treatment fails to yield a functional aortic valve, replacement of the valve is indicated.
Discrete subaortic stenosis can be cured in most patients by membranectomy associated with myectomy. Because the anatomic substrate is not addressed by these surgical techniques, however, recurrences are likely during long-term follow-up., particularly in patients who have a less than optimal relief of the LVOT gradient. In this subset of patients the optimalsurgical technique remains to be described. Intraoperative recording of left ventricle-aorta gradient, however, either by transesophageal echocardiography or by pressure measurement, remains an important tool for more aggressive subaortic resection in case of residual gradient greater than 30 mm Hg.