Left ventricular outflow tract obstruction
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
Left ventricular outflow tract obstruction refers to any functional or anatomic obstruction of flow out of the left ventricle.
Causes
- Aortic stenosis
- Hypertrophic obstructive cardiomyopathy
- Stress cardiomyopathy
- Subvalvular aortic stenosis
- Supravalvular aortic stenosis
ACC / AHA 2008 Guidelines- Recommendations for Evaluation of the Unoperated Patient (DO NOT EDIT)
| Class I |
| 1. Primary imaging and hemodynamic assessment of AS and aortic valve disease are recommended by echocardiography- Doppler to evaluate the presence and severity of AS or AR; LV size, function, and mass; and dimensions and anatomy of the ascending aorta and associated lesions. (Level of Evidence: B) |
| 2. Echocardiography is recommended for reevaluation of patients with AS who experience a change in signs or symptoms and for assessment of changes in AS hemodynamics during pregnancy. (Level of Evidence: B) |
| 3. In asymptomatic adolescents and young adults, echocardiography- Doppler is recommended yearly for AS with a mean Doppler gradient greater than 30 mm Hg or peak instantaneous gradient greater than 50 mm Hg and every 2 years for patients with lesser gradients.(Level of Evidence: C) |
| 4. Cardiac catheterization is recommended when noninvasive measurements are inconclusive or discordant with clinical signs. (Level of Evidence:C) |
| 5. Coronary angiography is recommended before aortic valve surgery for coronary angiography in adults at risk for coronary artery disease. (Level of Evidence:B) |
| 6. Coronary angiography is recommended before a Ross procedure if noninvasive imaging of the coronary arteries is inadequate. (Level of Evidence:C) |
| 7. A yearly ECG is recommended in young adults less than 30 years of age with mean Doppler gradients greater than 30 mm Hg or peak Doppler gradients greater than 50 mm Hg. (Level of Evidence:C) |
| 8. An ECG is recommended every other year in young adults less than 30 years of age with mean Doppler gradients less than 30 mm Hg or peak Doppler gradients less than 50 mm Hg. (Level of Evidence:C) |
| Class III (No Benefit) |
| 1. Genetic testing is not indicated in relatives when the index patient does not have a definitive pathogenic mutation. (Level of Evidence: B) |
| 2. Ongoing clinical screening is not indicated in genotype-negative relatives in families with HOCM. (Level of Evidence: B) |
| Class IIa |
| 1. Exercise stress testing should not be performed in symptomatic patients with AS or those with repolarization abnormality on ECG or systolic dysfunction on echocardiography. (Level of Evidence:C) |