BONUS QUESTION

16. What is systolic anterior motion (SAM) of the mitral valve?

Show answer
SAM is a complication of mitral valve repair. After mitral valve repair, the anterior leaflet of the mitral valve may billow into the left ventricular outflow tract during systole, creating two problems: (1) dynamic left ventricular outflow tract obstruction and (2) mitral regurgitation (anterior displacement of the anterior leaflet causes it to be foreshortened). SAM should be suspected if cardiac output is low after mitral valve repair and may be diagnosed by echocardiography. It is exacerbated by an increased contractile state of the myocardium, so inotropic agents should be avoided. Patients with SAM are treated by volume-loading and beta-blocking agents. If these measures fail, the valve should be replaced.

References
WEB SITE
http://www.acssurgery.com
BIBLIOGRAPHY
1. Bonow RO, Carabello B, de Leon AC Jr, et al: ACC/AHA guidelines for the management of patients with valvular heart disease. J Am Coll Cardiol 32:1486-1588, 1998. Full article
2. Carabello BA: The ten most commonly asked questions about mitral regurgitation. Cardiol Rev 10:321-322, 2002. Medline Similar articles Full article
3. Enruquez-Sarano M, Nkomo V, Mohty D, et al: Mitral regurgitation: Natural history in operated and nonoperated patients. Adv Cardiol 39:122-129, 2002.
4. Galloway AC, Grossi EA, Bizekis CS, et al: Evolving techniques for mitral valve reconstruction. Ann Thorac Surg 236:288-293, 2002. Full article
5. Irvine T, Li XK, Sahn DJ, Kenny A: Assessment of mitral regurgitation. Heart 88(suppl 4):iv11-19, 2002.