Left axis deviation - Wikipedia Left axis deviation The hexaxial reference system is a diagram that is used to determine the heart 's electrical axis in the frontal plane. In electrocardiography, left axis deviation ( LAD ) is a condition wherein the mean electrical axis of ventricular contraction of the heart lies in a frontal plane direction between − 30 ° and − 90 °. This is reflected by a QRS complex positive in lead I and negative in leads aVF and II. Contents 1 Cause 2 Diagnosis 3 See also 4 References Cause Common causes of LAD include left ventricular hypertrophy ( LVH ), left anterior fascicular block ( or hemiblock ) and inferior myocardial infarction. Less commonly LAD may be a normal variant, particularly in obese or stocky individuals, or it may be associated with Wolff -- Parkinson -- White syndrome or an ostium primum atrial septal defect. LVH is generally recognised as a cause of LAD, although some sources claim that LVH does not cause LAD. Diagnosis This section is empty. You can help by adding to it. ( September 2017 ) See also Right axis deviation References ^ Jump up to : Jenkins, Dean ( 1996 ). `` The electrical axis at a glance ''. www.ecglibrary.com. Retrieved 2016 - 11 - 12. ^ Jump up to : Lilly, Leonard ( 2006 ). Pathophysiology of Heart Disease. Lippincott Williams and Wilkins. ISBN 978 - 0 - 7817 - 6321 - 9. ^ Jump up to : Kasper D, Braunwald E, Fauci A, Hauser S, Longo D, Jameson J ( 2005 ). Harrison 's Principles of Internal Medicine ( 16th ed. ). McGraw - Hill. p. 1314. ISBN 0 - 07 - 147760 - 8. Jump up ^ Burns, Ed. `` Left Axis Deviation ( LAD ) ''. LITFL : Life in the Fast Lane Medical Blog. Retrieved 2016 - 11 - 12. Jump up ^ http://www.fpnotebook.com/cv/exam/LftAxsDvtn.htm Cardiovascular disease ( heart ) ( I00 -- I52, 390 -- 429 ) Ischaemic Coronary disease Coronary artery disease ( CAD ) Coronary artery aneurysm Spontaneous coronary artery dissection ( SCAD ) Coronary thrombosis Coronary vasospasm Myocardial bridge Active ischemia Angina pectoris Prinzmetal 's angina Stable angina Acute coronary syndrome Myocardial infarction Unstable angina Sequelae hours Hibernating myocardium Myocardial stunning days Myocardial rupture weeks Aneurysm of heart / Ventricular aneurysm Dressler syndrome Layers Pericardium Pericarditis Acute Chronic / Constrictive Pericardial effusion Cardiac tamponade Hemopericardium Myocardium Myocarditis Chagas disease Cardiomyopathy : Dilated ( Alcoholic ), Hypertrophic, and Restrictive Loeffler endocarditis Cardiac amyloidosis Endocardial fibroelastosis Arrhythmogenic right ventricular dysplasia Endocardium / valves Endocarditis infective endocarditis Subacute bacterial endocarditis non-infective endocarditis Libman -- Sacks endocarditis Nonbacterial thrombotic endocarditis Valves mitral regurgitation prolapse stenosis aortic stenosis insufficiency tricuspid stenosis insufficiency pulmonary stenosis insufficiency Conduction / arrhythmia Bradycardia Sinus bradycardia Sick sinus syndrome Heart block : Sinoatrial AV 1 ° 2 ° 3 ° Intraventricular Bundle branch block Right Left Left anterior fascicle Left posterior fascicle Bifascicular Trifascicular Adams -- Stokes syndrome Tachycardia ( paroxysmal and sinus ) Supraventricular Atrial Multifocal Junctional AV nodal reentrant Junctional ectopic Ventricular Accelerated idioventricular rhythm Catecholaminergic polymorphic Torsades de pointes Premature contraction Atrial Junctional Ventricular Pre-excitation syndrome Lown -- Ganong -- Levine Wolff -- Parkinson -- White Flutter / fibrillation Atrial flutter Ventricular flutter Atrial fibrillation Familial Ventricular fibrillation Pacemaker Ectopic pacemaker / Ectopic beat Multifocal atrial tachycardia Pacemaker syndrome Parasystole Wandering pacemaker Long QT syndrome Andersen -- Tawil Jervell and Lange - Nielsen Romano -- Ward Cardiac arrest Sudden cardiac death Asystole Pulseless electrical activity Sinoatrial arrest Other / ungrouped hexaxial reference system Right axis deviation Left axis deviation QT Short QT syndrome T wave alternans ST Osborn wave ST elevation ST depression Strain pattern Cardiomegaly Ventricular hypertrophy Left Right / Cor pulmonale Atrial enlargement Left Right Other Cardiac fibrosis Heart failure Diastolic heart failure Cardiac asthma Rheumatic fever This article about a medical condition affecting the circulatory system is a stub. You can help Wikipedia by expanding it. Retrieved from `` https://en.wikipedia.org/w/index.php?title=Left_axis_deviation&oldid=800666592 '' Categories : Circulatory disease stubs Cardiovascular physiology Hidden categories : Articles to be expanded from September 2017 All articles to be expanded Articles with empty sections from September 2017 All articles with empty sections Articles using small message boxes All stub articles Talk Contents About Wikipedia Add links This page was last edited on 14 September 2017, at 23 : 24. Text is available under the Creative Commons Attribution - ShareAlike License ; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy. Wikipedia ® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization. About Wikipedia

Question: what is the meaning of left axis deviation in ecg
Answer: a condition wherein the mean electrical axis of ventricular contraction of the heart lies in a frontal plane direction between −30° and −90°