CONDITION AND ITS EKG FEATURESEKG Left anterior fascicular block QRS duration < 0.10 sec QRS vector shows left axis deviation (LAD) in frontal plane > -30 degrees. QRS morphology Limb leads qR in leads I and aVL. rS in leads II, III, and aVF R peaks in aVL before aVR Precordial leads Delayed R wave transition Persistent S wave in V5-V6 Normal QRS morphology when precordial leads recorded in 2-3 interspaces higher Orthogonal leads qR in lead X rS in lead Y
