The most characteristic loops of left ventricular enlargement (LVE): (A) with the initial forces to the right and a positive T wave; (B) observed in cases of LVE that are not long-standing and with mild septal fibrosis; (C) QRS loops initially to the left and with counterclockwise rotation or figure-of-eight rotation on horizontal plane; corresponds to significant LVE seen in advanced heart diseases with significant septal fibrosis; (D) QRS loop with q wave of pseudonecrosis that occurs in cases of hypertrophic cardiomyopathy due to the presence of important septal vector; (E) QRS loop pointed approximately 0° on the horizontal plane with a very peaked T loop pointed upward, backward, and rightward characteristic for the apical type of hypertrophic cardiomyopathy. Bottom: Two examples of aortic valve disease, one (left) with mild septal fibrosis and normal ECG and VCG (presence of q wave in V6 as expression of first vector) and the other (right) with important septal fibrosis and abnormal ECG (ST-T with strain pattern) and VCG (absence of q wave in V6). See in the HP (H) with amplification of the loop (SE = 16) now in the left the qR in V6 coincides with initial vector forces of the loop in the negative hemifield of V6, and in the right with R in V6 the initial forces go directly to the left. Source: Chapter 15. Surface Electrocardiography, Hurst's The Heart, 13e Citation: Fuster V, Walsh RA, Harrington RA. Hurst's The Heart, 13e; 2011 Available at: https://accessmedicine.mhmedical.com/DownloadImage.aspx?image=/data/Books/hurs13/hurs13_c015f029.gif&sec=40282441&BookID=376&ChapterSecID=40279741&imagename= Accessed: October 11, 2017 Copyright © 2017 McGraw-Hill Education. All rights reserved