Congenital Heart Disease: Left Ventricular Outflow Tract Obstruction

Left ventricular outflow tract obstruction represents a wide spectrum of disease, including subvalvar aortic stenosis, valvar aortic stenosis, supravalvar aortic stenosis, coarctation of the aorta, and interrupted aortic arch. In some cases, these disorders may manifest in the fetal and early neonatal period, requiring early medical management or urgent surgical or catheter-based intervention. Patients presenting later often have chronic left ventricular pressure overload, compensatory hypertrophy with altered ventricular diastolic properties, and arterial hypertension. Most of these conditions are easily diagnosed by physical examination, electrocardiography, chest radiography, and two-dimensional echocardiography with Doppler. Diagnostic catheterization may be helpful if the diagnosis is in question, for precise determination of pressure gradients, or for providing further anatomic detail via angiography. The threshold for invasive therapy varies with the location of the obstruction and its natural history. Catheter-based intervention is commonly utilized for valvar aortic stenosis and coarctation, with success rates varying based on disease type and location. Surgical intervention is indicated for interrupted aortic arch, certain types of valvar aortic stenosis and coarctation deemed not suitable for catheter-based intervention, and for subvalvar and supravalvar aortic stenosis of adequate severity. Lifelong follow-up is generally recommended, as recurrence requiring reintervention may occur.