. Author manuscript; available in PMC: 2011 Sep 1.
Published in final edited form as: J Am Soc Echocardiogr. 2010 Aug 8;23(9):1001–1006. doi: 10.1016/j.echo.2010.06.024
© 2010 American Society of Echocardiography. Published by Mosby, Inc. All rights reserved.