is left axis deviation ecg dangerous

Cardiac: Differential diagnosis: Other important EKG clues: Normal Variant: Left Ventricular Hypertrophy: Sum of S wave in V1 and R wave in V5 or V6 3.5 mV (35 mm) R wave in aVL 1.1 mV (11 . background: #fff; DONT FORGET these 3 key components of the cardiovascular exam for your upcoming OSCEs Save this video to watch later and dont forget to follow Geeky Medics! But no matter what your blood pressure is, developing left ventricular hypertrophy puts you at higher risk of congestive heart failure and irregular heart rhythms. sinus rhythm with premature supraventricular complexes left axis deviation minimal voltage criteria for lvh, may be normal variant abnormal ecg? I just had a ecg and it said left axis deviation and a t wave abnormality. Emergency Physician in Prehospital and Retrieval Medicine in Sydney, Australia. PMC Analytical cookies are used to understand how visitors interact with the website. The QRS duration is only slightly prolonged but it does not reach 0.12 s. Block in the anterior fascicle causes left anterior fascicular block (LAFB). PDF Axis Deviation/Heart Blocks - Tampa General Hospital Note that left-axis deviation on the ECG may appear in both pregnant and obese patients. Left posterior fascicular block is much less common than LAFB. What Pathology Is Seen With Left Axis Deviation | Steve Gallik An EKG/ECG is a representation of the electrical activity of the heart muscle as it changes with time. Weight Loss: 7 Tips That Will Help You Practice Mindful Eating. Retrieved 2022-10-25., ventricular ectopic arrhythmias, congenital cardiac disease, preexcitation syndrome, pacemaker-generated paced rhythm, conduction abnormalities, mechanical shift, emphysema, normal variation, and hyperkalemia are all examples of these. Refer to Figure 1. What is left axis deviation on an ekg? Brenyo A, Rao M, Barsheshet A, Cannom D, Quesada A, McNitt S, Huang DT, Moss AJ, Zareba W. J Cardiovasc Electrophysiol. The Isoelectric lead is another technique of measuring LAD that allows for a more exact calculation of the axis of the QRS. Please enable it to take advantage of the complete set of features! This is reflected by a QRS complex positive in lead I and negative in leads aVF and II. The clinical significance of the electrocardiographic aberration called abnormal left axis. Check out our other awesome clinical skills resources including: Unauthorized use of these marks is strictly prohibited. Is left axis deviation life threatening? - Studybuff We would like to show you notifications for the latest Health and Dentalcare news and updates. If the QRS complex in lead II is positive, this indicates a normal axis. What causes an anteroseptal infarct? Symptoms, treatment, and prevention We sought to better stratify which patients with LAD but without previously known HD may warrant additional workup. ECG Changes in a Patient Presenting With Chest Pain Secondary to Left-Sided Primary Spontaneous Pneumothorax: A Case Report-Based Literature Review. How To Read an EKG/ECG Electrocardiogram - Nurse.org Add Left Axis Deviation (LAD)| Learn More About the Pathologies of the Heart by Determining the Left Deviations of its Electrical Axis to Home Screen, 1) Press the share button on your browser's menu bar. Diabetes Care. Extreme Axis Deviation = QRS axis between -90 and 180 (AKA "Northwest Axis") Clipboard, Search History, and several other advanced features are temporarily unavailable. This is mirrored by a positive QRS complex in lead I and a negative complex in leads aVF & II. Late Incidental Discovery of Compression of the Left Anterior Some of the causes include normal variation, thickened left . Pathological Left Axis Deviation: Causes Symptoms And Treatment Refer to Figure 1. Educational text answers on HealthTap are not intended for individual diagnosis, treatment or prescription. Axis deviation indicates possible presence of various conditions. LAD is usually caused by conduction abnormalities. These cookies track visitors across websites and collect information to provide customized ads. In case of sale of your personal information, you may opt out by using the link. (2021) van der Ree et al. LAD may be caused by a number of factors. If, in contrast, the QRS complex in lead II is negative, this indicates a LAD. Left Axis Deviation - My EKG Federal government websites often end in .gov or .mil. Approximately 510% of all individuals have a third fascicle the median or centroseptal fascicle whichgives off Purkinje fibers to the interventricular septum. Respiratory sinus arrhythmia is effectively benign, meaning that it is not harmful. You can check out our guide to using SOCRATES here: https://geekymedics.com/the-socrates-acronym-in-history-taking/ One of the key steps in interpreting an electrocardiogram (EKG) is determining the electrical axis of the heart. - Over 3000 Free MCQs: https://geekyquiz.com/ If LAD is caused by left ventricular hypertrophy, therapy is determined by the underlying etiology of the enlargement. If LVH is caused by valvular abnormalities like aortic valve stenosis, the valve must be surgically repaired or replaced. Whenever the direction of electrical activity is towards a lead you get a positive deflection in that lead. What is the mechanism action of H. pylori? Non-specific Intraventricular Conduction Delay, Overview of Intraventricular Conduction Defects. Doctors typically provide answers within 24 hours. We proceeded to the implantation of a new IS1 RV lead (Ingevity, Boston Scientific, Marlborough, MA, USA), an IS4 left ventricular (LV) lead (Attain, Medtronic . The bottom EKG shows a reading of a person with left anterior fascicular block (LAFB), previously thought to be benign but found by a UCSF-led team to potentially signal a serious heart condition. 8600 Rockville Pike EKG- Disorders of Axis - Cancer Therapy Advisor Left axis deviation (LAD) involves the direction of depolarisation being distorted to the left (between -30 and -90). The electrical axis will be shifted to the left (left axis deviation), ranging between -45 and -90. We are increasingly noticing isolated left axis deviation (LAD) in electrocardiogram in younger people with diabetes without obvious heart disease and association of LAD with glucose intolerance has not been explicitly raised before. The PubMed wordmark and PubMed logo are registered trademarks of the U.S. Department of Health and Human Services (HHS). An abnormal left axis deviation is a condition where the heart's electrical axis is shifted to the left. www.heart.org. I am currently continuing at SunAgri as an R&D engineer. Simply so, is left axis deviation serious? A careful history to elicit acute cardiac injury is therefore of utmost importance. Depolarization of the left ventricle will depend entirely on impulses from the anterior fascicle if the posterior one is defect. Clinical electrocardiography and ECG interpretation, Cardiac electrophysiology: action potential, automaticity and vectors, The ECG leads: electrodes, limb leads, chest (precordial) leads, 12-Lead ECG (EKG), The Cabrera format of the 12-lead ECG & lead aVR instead of aVR, ECG interpretation: Characteristics of the normal ECG (P-wave, QRS complex, ST segment, T-wave), How to interpret the ECG / EKG: A systematic approach, Mechanisms of cardiac arrhythmias: from automaticity to re-entry (reentry), Aberrant ventricular conduction (aberrancy, aberration), Premature ventricular contractions (premature ventricular complex, premature ventricular beats), Premature atrial contraction(premature atrial beat / complex): ECG & clinical implications, Sinus rhythm: physiology, ECG criteria & clinical implications, Sinus arrhythmia (respiratory sinus arrhythmia), Sinus bradycardia: definitions, ECG, causes and management, Chronotropic incompetence (inability to increase heart rate), Sinoatrial arrest & sinoatrial pause (sinus pause / arrest), Sinoatrial block (SA block): ECG criteria, causes and clinical features, Sinus node dysfunction (SND) and sick sinus syndrome (SSS), Sinus tachycardia & Inappropriate sinus tachycardia, Atrial fibrillation: ECG, classification, causes, risk factors & management, Atrial flutter: classification, causes, ECG diagnosis & management, Ectopic atrial rhythm (EAT), atrial tachycardia (AT) & multifocal atrial tachycardia (MAT), Atrioventricular nodal reentry tachycardia (AVNRT): ECG features & management, Pre-excitation, Atrioventricular Reentrant (Reentry) Tachycardia (AVRT), Wolff-Parkinson-White (WPW) syndrome, Junctional rhythm (escape rhythm) and junctional tachycardia, Ventricular rhythm and accelerated ventricular rhythm (idioventricular rhythm), Ventricular tachycardia (VT): ECG criteria, causes, classification, treatment, Long QT (QTc) interval, long QT syndrome (LQTS) & torsades de pointes, Ventricular fibrillation, pulseless electrical activity and sudden cardiac arrest, Pacemaker mediated tachycardia (PMT): ECG and management, Diagnosis and management of narrow and wide complex tachycardia, Introduction to Coronary Artery Disease (Ischemic Heart Disease) & Use of ECG, Classification of Acute Coronary Syndromes (ACS) & Acute Myocardial Infarction (AMI), Clinical application of ECG in chest pain & acute myocardial infarction, Diagnostic Criteria for Acute Myocardial Infarction: Cardiac troponins, ECG & Symptoms, Myocardial Ischemia & infarction: Reactions, ECG Changes & Symptoms, The left ventricle in myocardial ischemia and infarction, Factors that modify the natural course in acute myocardial infarction (AMI), ECG in myocardial ischemia: ischemic changes in the ST segment & T-wave, ST segment depression in myocardial ischemia and differential diagnoses, ST segment elevation in acute myocardial ischemia and differential diagnoses, ST elevation myocardial infarction (STEMI) without ST elevations on 12-lead ECG, T-waves in ischemia: hyperacute, inverted (negative), Wellen's sign & de Winter's sign, ECG signs of myocardial infarction: pathological Q-waves & pathological R-waves, Other ECG changes in ischemia and infarction, Supraventricular and intraventricular conduction defects in myocardial ischemia and infarction, ECG localization of myocardial infarction / ischemia and coronary artery occlusion (culprit), The ECG in assessment of myocardial reperfusion, Approach to patients with chest pain: differential diagnoses, management & ECG, Stable Coronary Artery Disease (Angina Pectoris): Diagnosis, Evaluation, Management, NSTEMI (Non ST Elevation Myocardial Infarction) & Unstable Angina: Diagnosis, Criteria, ECG, Management, STEMI (ST Elevation Myocardial Infarction): diagnosis, criteria, ECG & management, First-degree AV block (AV block I, AV block 1), Second-degree AV block: Mobitz type 1 (Wenckebach) & Mobitz type 2 block, Third-degree AV block (3rd degree AV block, AV block 3, AV block III), Management and treatment of AV block (atrioventricular blocks), Intraventricular conduction delay: bundle branch blocks & fascicular blocks, Right bundle branch block (RBBB): ECG, criteria, definitions, causes & treatment, Left bundle branch block (LBBB): ECG criteria, causes, management, Left bundle branch block (LBBB) in acute myocardial infarction: the Sgarbossa criteria, Fascicular block (hemiblock): left anterior & left posterior fascicular block on ECG, Nonspecific intraventricular conduction delay (defect), Atrial and ventricular enlargement: hypertrophy and dilatation on ECG, ECG in left ventricular hypertrophy (LVH): criteria and implications, Right ventricular hypertrophy (RVH): ECG criteria & clinical characteristics, Biventricular hypertrophy ECG and clinical characteristics, Left atrial enlargement (P mitrale) & right atrial enlargement (P pulmonale) on ECG, Digoxin - ECG changes, arrhythmias, conduction defects & treatment, ECG changes caused by antiarrhythmic drugs, beta blockers & calcium channel blockers, ECG changes due to electrolyte imbalance (disorder), ECG J wave syndromes: hypothermia, early repolarization, hypercalcemia & Brugada syndrome, Brugada syndrome: ECG, clinical features and management, Early repolarization pattern on ECG (early repolarization syndrome), Takotsubo cardiomyopathy (broken heart syndrome, stress induced cardiomyopathy), Pericarditis, myocarditis & perimyocarditis: ECG, criteria & treatment, Eletrical alternans: the ECG in pericardial effusion & cardiac tamponade, Exercise stress test (treadmill test, exercise ECG): Introduction, Indications, Contraindications, and Preparations for Exercise Stress Testing (exercise ECG), Exercise stress test (exercise ECG): protocols, evaluation & termination, Exercise stress testing in special patient populations, Exercise physiology: from normal response to myocardial ischemia & chest pain, Evaluation of exercise stress test: ECG, symptoms, blood pressure, heart rate, performance, ECG criteria for left anterior fascicular block (LAFB), Causes of left anterior fascicular block (LAFB), Prognosis of left anterior fascicular block (LAFB), Noteworthy about left anterior fascicular block (LAFB), ECG criteria for left posterior fascicular block (LPFB), Causes of left posterior fascicular block (LPFB), Causes ofleft anterior fascicular block (LAFB), Prognosis ofleft anterior fascicular block (LAFB), Noteworthy aboutleft anterior fascicular block (LAFB), Causes ofleft posterior fascicular block (LPFB). To understand the cardiac axis, one must first discover the connection between both the QRS axis and the ECG limb leads. Company registered in USA & NIGERIA by, Left Axis Deviation (LAD)| Learn More About the Pathologies of the Heart by Determining the Left Deviations of its Electrical Axis. This is reflected by a QRS complex positive in lead I and negative in leads aVF and II.. The DSM V changed the axis system from 5 to 4, eliminating axis 5 Gaf rating due to rarer subjectivity bias. In contrast, LAD is defined as a QRS axis between 30 and 90, right axis deviation (RAD) is defined as a QRS axis higher than +90, and extreme axis deviation (EAD) is defined as a QRS axis between -90 to 180. "The electrical axis at a glance". The majority of those with LAFB, however, have significant heart disease. This website uses cookies to improve your experience while you navigate through the website. If the left and right arm leads are reversed, lead I will show inverted P and T with a predominantly negative QRS whilst V leads are normal. But opting out of some of these cookies may have an effect on your browsing experience. By clicking Accept, you consent to the use of ALL the cookies. Heart failure. Inferior wall myocardial infarction, left ventricular hypertrophy3"Left ventricular hypertrophy - Diagnosis and treatment - Mayo Clinic". The ECG axis may be determined in a variety of ways. Among 67,375 Air Force men without symptoms, Hiss and associates found a frontal plane QRS axis of 30 to 90 degrees in 128 (1.9 percent). The causes of axis deviation are discussed below. (= Left Axis Deviation, LAD) . Among 67,375 Air Force men without symptoms, Hiss and associates found a frontal plane QRS axis of 30 to 90 degrees in 128 (1.9 percent). Is my husband getting the right treatment? Electrical Right and Left Axis Deviation Article - StatPearls Left Anterior Fascicular Block (LAFB) - EMS 12-Lead What is the meaning of left axis deviation in an ECG? - Doctor.ndtv.com www.mayoclinic. The QRS duration will be slightly prolonged (the prolongation ranges between 0.01 to 0.04 seconds). Other times, an abnormal ECG can signal a medical emergency, such as a myocardial infarction /heart attack or a dangerous arrhythmia. The abnormal left axis deviation is one of the most common abnormal ECG findings. RAD is commonly associated with conditions such as pulmonary hypertension, as they cause right ventricular hypertrophy. The normal variation that causes LAD is a physiologic alteration that occurs with age. Blood pressure medication may help prevent further enlargement of the left ventricle and even shrink your hypertrophic muscles. A simple explanation to help you interpret the axis next time you encounter an ECG. It can be used to diagnose heart attacks and other heart problems. Moderate-to-marked LAD group had higher frequencies of abnormal blood pressure (BP), FPG, and lipids than borderline LAD group even after conditioning effects of age and sex (p0.03) and of FPG after conditioning effects of BP (p=0.02). Clinic and electro-vectorcardiographic study (author's transl)]. "What is Left Ventricular Hypertrophy (LVH)?". A careful history to elicit acute . Why do healthcare facilities prefer outsourcing hospital billing services? Twitter: http://www.twitter.com/geekymedics Left anterior fascicular block - UpToDate Electrical Right and Left Axis Deviation - NCBI Bookshelf #mc-embedded-subscribe-form input[type=checkbox] { - Is Left Axis Deviation ECG Dangerous or Can LAD Cause Death? Although left axis deviation is often an age-related physiological change. The electrical axis will be more positive than 90 (right axis deviation). What is the association between H. pylori and development of. Left axis deviation = QRS axis between -30 to -90 degrees. Electrode placement for pediatric patients. sharing sensitive information, make sure youre on a federal Facebook: http://www.facebook.com/geekymedics (left axis deviation, or LAD) - QRS is upright in lead I (positive) and downward in lead aVF . It is usually the result of a left anterior hemiblock rather than to the increased bulk of muscle of the left ventricle. Based on a work athttps://litfl.com. Adult electrodes will overlap and potentially cause inaccurate . If the deviation is due to left ventricular hypertrophy (LVH) and the hypertrophy has resulted in heart failure, then the patient may demonstrate such symptoms of heart failure as dyspnea on exertion or leg edema. answered any questions you had concerning the left axis deviation of the heart. and transmitted securely. The prevalence of left-axis deviation (LAD) (QRS axis of -30 degrees or less) was not higher among those with greater measures of body fatness. National Library of Medicine Left anterior fascicular block or LAFB also known left anterior hemiblock, is a heart disease in which scarring occurs in a section of the left ventricle identifiable from an abnormal electrocardiogram (ECG). 2013 Apr;24(4):442-8. doi: 10.1111/jce.12057. } The left bundle branch is subdivided into the following two fascicles: (1)the anterior (anterosuperior) fascicle, whichdelivers the electrical impulse to the anterior wall of the left ventricle; (2)the posterior (posteroinferior) fascicle, whichdelivers the electrical impulse to the posterior and inferiorwalls of the left ventricle. There may be extreme axis deviation. Normal sinus rhythm with right axis deviation. Although not a dangerous finding in and of itself, axis deviation may be an indication of a serious underlying condition. An echocardiogram can usually rule o Left axis means on your ekg them sum of your electrical vectors from your heart was 0 to negative 90 degrees on the EKG. Left axis deviation is a condition in which the electrical axis of the heart's ventricular depolarization is abnormally positioned between negative 30 and negative 90, which suggests an underlying anatomical or physiological condition is affecting the electrical conduction system of the heart. - Medical Finals Question Pack: https://geekymedics.com/medical-student-finals-questions/ - Examples 05:45 eCollection 2020. Normal variation, pre-excitation syndrome, conduction defects, inferior wall myocardial infarction, congenital heart disease, ventricular ectopic rhythms, emphysema, mechanical shift, high potassium levels, paced rhythm, and thickened left ventricle are just a few of the causes. Introduction: We are increasingly noticing isolated left axis deviation (LAD) in electrocardiogram in younger people with diabetes without obvious heart disease and association of LAD with glucose intolerance has not been explicitly raised before. If the electrical axis is between -30 to -90 this is considered left axis deviation. Learn how your comment data is processed. This allows us to get in touch for more details if required. Out of 100 participants enrolled, about 90% were aged between 30 and 60 and 47% had borderline and 53% moderate-to-marked LAD. There are several potential causes of LAD. What does right axis deviation mean on ECG? - KnowledgeBurrow.com And always remember that. DO NOT perform any examination or procedure on patients based purely on the content of these videos. In the old DSM 4, which most still use, there are 5 Axes of mental health. Cumulative 10-year survival was 73.7% among patients with normal left atrial size, 62.5% among those with mild enlargement, 54.8% among those with moderate enlargement and 45% among those with severe enlargement (p < 0.001). And always remember that Healthsoothe is one of the best health sites out there that genuinely cares for you. ECG findings Comment; A (normal or normal variant ECG reading) Sinus bradycardia, arrhythmia, or tachycardia . Check QRS in lead II to identify a real LAD. Left ventricular hypertrophy is more common in people who have uncontrolled high blood pressure. Left ventricular hypertrophy - Diagnosis and treatment - Mayo Clinic Alboni P, Longhini C, Malacarne C, Giovannini G. Cardin G, Nava A, Canciani B, Bottero M, Zevallos JC, Buja GF. In healthy individuals, you would expect the axis to lie between -30and +90. rS complexes in leads I and aVL. Figure 2 . } Hence it is a 4 axis system that acts as A left axis may be normal for you, or may indicate some thickening of your left ventricle. This category only includes cookies that ensures basic functionalities and security features of the website. If the electrical axis falls between the values of -30 to +90 this is considered normal. Geeky Medics accepts no liability for loss of any kind incurred as a result of reliance upon the information provided in this video. A careful history to elicit acute cardiac injury is therefore of utmost importance. Establishing a diagnosis of LPFB requires that there are no clinical or ECG criteria of right ventricular hypertrophy present. For these, please consult a doctor (virtually or in person). Left axis deviation (LAD) is a condition in electrocardiography in which the average electrical axis of the ventricular contraction of the heart rests in a frontal plane direction between 30 and 901https://en.wikipedia.org/wiki/Left_axis_deviation. www.ecglibrary.com. rS complexes in leads II, III and aVF may mask. I love to write and share science related Stuff Here on my Website. The ECG records heart electrical activity. A number of things can result in right axis deviation which include lung disease, right sided heart strain, right bundle branch block, and right ventricular hypertrophy. #geekymedics #fyp #fypviral #studytok #medicalstudentuk #medtok #studytips #studytipsforstudents #medstudentuk #premed #medschoolfinals #shorts, Cardiovascular Exam Tips - DON'T FORGET these 3 things , Watch this video to find out the most COMMONLY FORGOTTEN components of the cardiovascular history! Save this video to help prepare for your upcoming OSCEs and dont forget to follow Geeky Medics! Healthsoothe does not provide medical advice, diagnosis, or treatment. Although not a dangerous finding in and of itself, axis deviation may be an indication of a serious underlying condition. What is the difference between hypoxemia and hypoventilation? For example, if LAD is caused by left ventricular hypertrophy. The electrical activity of the heart starts at the sinoatrialnode then spreads to the atrioventricular (AV)node. In case of a fascicular block, the wall/walls without fascicular supply will depend on impulses spreading from the other part of the ventricle (where the fascicle is intact). qR complexes in inferior leads (II, III and aVF). Fascicular block (hemiblock): left anterior & left - ECG & ECHO Herein, we will discuss what makes up the electrical axis, ventricular (QRS) axis, axis classifications . In this condition there is a swing of the cardiac axis to the left - ie less than minus 30 degrees. Top answers from doctors based on your search: Created for people with ongoing healthcare needs but benefits everyone. Is the left axis deviation dangerous? There currently is no treatment for people with LAFB. Twitter: @rob_buttner. Whenever the direction of electrical activity is away from a lead you get a negative deflection in that lead. Left axis deviation by definition is a coronal QRS axis of more than -30 degrees. Bookshelf Normal Axis = QRS axis between -30 and +90, Right Axis Deviation = QRS axis greater than +90, Extreme Axis Deviation = QRS axis between -90 and 180 (AKA Northwest Axis), Angiotensin-converting enzyme (ACE) inhibitors. Dangerous ECG in the Ward | Circulation Out of these cookies, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. (between +90 and +180) An extreme heart axis is present when both I and AVF are negative. DO NOT perform any examination or procedure on patients based purely on the content of these videos. An official website of the United States government. Disclaimer. A comprehensive collection of medical revision notes that cover a broad range of clinical topics. Special interests in diagnostic and procedural ultrasound, medical education, and ECG interpretation. Left Axis Deviation (LAD)| Learn More About The Pathologies Of The Subscribe to our newsletter to be the first to know about our latest content: https://geekymedics.com/newsletter/ This results in the deflection of lead III becoming negative (this is only considered significant if the deflection of lead II also becomes negative). Connect with a U.S. board-certified doctor by text or video anytime, anywhere. ECG criteria for left posterior fascicular block (LPFB) Electrical axis +90 to +180. Do I need to change medicines after angioplasty? And dont worry, You can always check our FAQs section below to know more about left axis deviation. Electrocardiography. margin-top: 20px; RAD can, however, be a normal finding in very tall individuals. It can be normal, leftward (left axis deviation, or LAD), rightward (right axis deviation, or RAD) or indeterminate (northwest axis). A research was carried out, and the results were that the development of left axis deviation in people of 40-59yr of age, independent of blood pressure is a significant predictor of ischemic heart disease events that are usually manifest 5-10yr after the onset of this electrocardiographic abnormality. < ..^^>. AHA Releases Recommendations on Cardiovascular Monitoring and - AAFP Introduction. Is your body's hormone capable of affecting your hunger pangs? The mean QRS axis during the first 4 weeks of life is +110 degrees or more.104 After 1 month the average axis is less than +90 degrees (although a significant number of children still have a QRS axis of up to +110 degrees). 2005 Dec;98(12):1232-8. Heart valve disease. This test is performed on patients who present symptoms such as chest pain, heaviness in the chest, dizziness, or shortness of breath. Unable to load your collection due to an error, Unable to load your delegates due to an error. - Geeky Medics OSCE App: https://geekymedics.com/geeky-medics-app/ These cookies help provide information on metrics the number of visitors, bounce rate, traffic source, etc. The initial vector will be directed inferiorly (Figure 1, panel A), yielding a small r-wave in inferior leads (II, III and aVF) and small q-wave in lateral leads (aVL, I and -aVR). Isolated LAFB is considered a benign conduction defect. Please enable it to take advantage of the complete set of features! Anatomical or functional block in the anterior fascicle leads toleft anterior fascicular block. This prevents the lower left heart chamber from filling properly with blood. The underlying cause determines the symptoms and treatment for left axis deviation. The Electrocardiogram (ECG) . - Site 01:12 One of the key steps in interpreting an electrocardiogram (ECG .