Two-dimensional echocardiogram from a patient with severe hypertrophic cardiomyopathy. There is a severe increase in left ventricular wall thickness, with a much greater increase in thickness of the ventricular septum (VS). The ratio of ventricular septal thickness to posterior wall (PW) thickness is 2.5:1. Left: Parasternal long axis view during diastole. Right: Parasternal long axis view during systole. There is systolic anterior motion of the mitral valve causing left ventricular outflow tract obstruction. Ao, aorta; LA, left atrium; LV, left ventricle. Source: Chapter 33. Hypertrophic Cardiomyopathy, Hurst's The Heart, 13e Citation: Fuster V, Walsh RA, Harrington RA. Hurst's The Heart, 13e; 2011 Available at: http://accessmedicine.mhmedical.com/DownloadImage.aspx?image=/data/books/hurs13/hurs13_c033f010a.jpg&sec=40286183&BookID=376&ChapterSecID=40279761&imagename= Accessed: October 08, 2017 Copyright © 2017 McGraw-Hill Education. All rights reserved