Ebook ECG short rapid review for non-Cardiologists (edition 2.1): Part 1

(BQ) Part 1 book ECG short rapid review for non-Cardiologists presents the following contents: ECG basics, general physiological terms, sinus rhythms, atrio - Ventricular arrythmias. Invite you to consult.

ECG Short Rapid Review For Non-Cardiologists Edition 2.1 (PocketBook) Review Medicine with us at : www.twitter.com/MedRx22 Dr CHIRAG NAVADIA 2013 **ABOUT BOOK ** Hello Dear Friends , I am Dr Chirag Navadia & Its my pleasure to present this ECG book as a compact version of other detailed ECG books This book is meant to be for all the Doctors , Nurses and Students around the world If you are curious to learn ECG Basics, then this is the book for you which is prepared after reviewing many other books out there These are some 50+ must know basic ECG with Interpretations, Clinical Presentation, Etiologies & Managements As this is a Review Book , It does not contain All Treatments in Detail Emphasize has been made to include all clinically relevant important points Please See the index for more details about the topics in this book I hope you will enjoy this book and will not regret your purchase Best Wishes For Your Brilliant Future Sincerely Dr Chirag Navadia 2|Page “Book is dedicated to my Parents , Friends, All College professors and Tutors of Kaplan Medical , USMLE First Aid , Dr Edward Goljan , Dr Hussain Sattar , Dr Najeeb Thanks for giving me most valuable knowledge of my life “ Copyrights© 2013 Chirag Navadia Certain ECG images were freely available on Internet & belongs to their Owner No part of this book may be reproduced in any form , by Photostat , microfilm , xerography or any other mean , or incorporated into any information retrieval system , electronic or mechanical , without the written permission of Chirag Navadia 3|Page TABLE OF CONTENTS CHAPTER : ECG BASICS……………………………………………………8 1.1 SHORT INTRODUCTION 1.2 CONDUCTION PATHWAY 11 1.3 BLOOD SUPPLY TO HEART 12 1.4 ACTION POTENTIALS 14 1.5 PHASES OF CARDIAC CYCLE 17 GENERAL PHYSIOLOGICAL TERMS 20 1.6 ECG RECORDING 22 1.8 BEST METHOD TO DETERMINE HEART RATE 29 1.9 TYPES OF ECG 30 1.10 STANDARD CHEST LEAD PLACEMENT OF ELECTRODES 33 1.11 CORONARY TERRITORY ON 12 LEAD ECG 35 1.12 ANALYSING THE RHYTHM 36 CHAPTER : SINUS RHYTHMS……………………………………………38 Normal ECG 38 Normal 12-Lead ECG 39 SINUS ARRYTHMIAS 40 SINUS BRADYCARDIA 41 SINUS TACHYCARDIA 43 SINUS PAUSE 45 4|Page CHAPTER : ATRIO-VENTRICULAR ARRYTHMIAS …………………………47 ATRIAL TACHYCARDIA 47 MULTIFOCAL ATRIAL TACHYCARDIA 49 ATRIAL FLUTTER 50 ATRIAL FIBRILLATION 52 PREMATURE ATRIAL CONTRACTION 54 SUPRAVENTRICULAR TACHYCARDIA 56 PAROXYSMAL SUPRAVENTRICULAR TACHYCARDIA 57 WANDERING ATRIAL PACEMAKER 60 CHAPTER : VENTRICULAR ARRYTHMIAS…………………………… 61 IDIOVENTRICULAR RHYTHM 61 ACCELETATED IDIOVENTRICULAR RHYTHM 62 VENTRICULAR TACHYCARDIA (MONOMORPHIC) 63 VENTRICULAR TACHYCARDIA (POLYMORPHIC) 65 VENTRICULAR FIBRILLATION 66 TORSADE DE POINTES 68 PULSELESS ELECTRICAL ACTIVITY 69 ASYSTOLE 71 CHAPTER : HEART BLOCKS……………………………….…………….72 ATRIOVENTRICULAR BLOCKS (FIRST DEGREE BLOCK) 72 2ND DEGREE AV BLOCK : MOBITZ TYPE I 74 2ND DEGREE AV BLOCK : MOBITZ TYPE II 75 5|Page 3RD DEGREE AV BLOCK 77 SINOATRIAL BLOCK (SA BLOCK) 78 RIGHT & lEFT BUNDLE BRANCH BLOCKS 79 CHAPTER : MYOCARDIAL INFARCTION………………………………82 ECG CHANGE FROM DAY TO YEAR LATER 86 ST SEGMENT CHANGES FROM ISCHEMIA TO MI 87 ST SEGMENT ELEVATION & DEPRESSION 88 INFERIOR WALL MI 91 ANTERIOR WALL MI 92 LATERAL WALL MI 93 CHAPTER : JUNCTIONAL ARRYTHMIAS……………………………….94 JUNCTIONAL RHYTHM 94 ACCELERATED JUNCTIONAL RHYTHM 95 JUNCTIONAL ESCAPE BEATS 96 WOLF-PARKINSON WHITE SYNDROME 97 PREMATURE JUCTIONAL CONTRACTIONS 98 SINGLE CHAMBER PACEMAKER RHYTHM - VENTRICULAR 99 SINGLE CHAMBER PACEMAKER RHYTHM - ATRIAL 100 DUAL CHAMBER PACEMAKER RHYTHM – ATRIAL & VENTRICULAR 100 CHAPTER : PREMATURE VENTRICULAR CONTRACTIONS…………101 PVC : UNIFORM VS MULTIFORM 102 6|Page PVC : VENTRICULAR BIGEMINY VS TRIGEMINY 103 PVC : VENTRICULAR QUADRIGEMINY VS COUPLETS 104 CHAPTER : MISCELLANEOUS………………………………………… 106 HYPERKALEMIA VS HYPOKALEMIA 106 HYPERCALCEMIA VS HYPOCALCEMIA 109 CHAPTER : P & Q WAVE RELATIONSHIPS……………………………112 P MITRALE/P SINISTROCARDIALE (MITRAL STENOSIS) 113 P PULMONALE (COR PULMONALE) 114 RIGHT ATRIAL ENLARGEMENT 114 LEFT ATRIAL ENLARGEMENT 115 MECHANISM OF Q WAVE 116 ACUTE PERICARDITIS 117 CARDIAC PHARMACOLOGY……………………………………………….118 ANTI-ARRYTHMIC DRUGS 118 ANTIHYPERTENSIVE DRUGS 125 ANTIHYPERLIPIDEMIC DRUGS 128 NON PHARMACOLOGICAL TREATMENTS 130 References 132 7|Page CHAPTER : ECG BASI CS 1.1 SHORT INTRODUCTION Electrocardiogram (ECG) The electrocardiogram is commonly used to detect abnormal heart rhythms and to investigate the cause of chest pains What is an electrocardiogram? An electrocardiogram (ECG) records the electrical activity of the heart The heart produces tiny electrical impulses which spread through the heart muscle to make the heart contract These impulses can be detected by the ECG machine You may have an ECG to help find the cause of symptoms such as palpitations or chest pain Sometimes it is done as part of routine tests - for example, before you have an operation The ECG test is painless and harmless (The ECG machine records electrical impulses coming from your body - it does not put any electricity into your body.) How is it done? Small metal electrodes are stuck on to your arms, legs and chest Wires from the electrodes are connected to the ECG machine The machine detects and amplifies the electrical impulses that occur at each heartbeat and records them on to a paper or computer A few heartbeats are recorded from different sets of electrodes The test takes about five minutes to Usually, more than two electrodes are used, and they can be combined into a number of pairs (For example: left arm (LA), right arm (RA) and left leg (LL) electrodes form the three pairs LA+RA, LA+LL, and RA+LL) The output from each pair is known as a lead Each lead 8|Page looks at the heart from a different angle Different types of ECGs can be referred to by the number of leads that are recorded, for example 3-lead, 5-lead or 12-lead ECGs (sometimes simply "a 12-lead") A 12-lead ECG is one in which 12 different electrical signals are recorded at approximately the same time and will often be used as a one-off recording of an ECG, traditionally printed out as a paper copy Three- and 5lead ECGs tend to be monitored continuously and viewed only on the screen of an appropriate monitoring device, for example during an operation or while being transported in an ambulance There may or may not be any permanent record of a 3- or 5-lead ECG, depending on the equipment used What does an electrocardiogram show? The electrodes on the different parts of the body detect electrical impulses coming from different directions within the heart There are normal patterns for each electrode Various heart disorders produce abnormal patterns The heart disorders that can be detected include : -Abnormal heart rhythms If the heart rate is very fast, very slow, or irregular There are various types of irregular heart rhythm with characteristic ECG patterns -A heart attack (myocardial infarction), Whether it was recent or some time ago A heart attack causes damage to heart muscle, and heals with scar tissue These can be detected by abnormal ECG patterns -An enlarged heart Basically, this causes bigger impulses than normal All Other ECG are discussed in detail from Chapter onwards 9|Page Limitations of the electrocardiogram An ECG is a simple and valuable test Sometimes it can definitely diagnose a heart problem However, a normal ECG does not rule out serious heart disease For example, you may have an irregular heart rhythm that 'comes and goes', and the recording can be normal between episodes Also, not all heart attacks can be detected by ECG Angina, a common heart disorder, cannot usually be detected by a routine ECG Specialised ECG recordings sometimes help to overcome some limitations For example: Exercise ECG This is where the tracing is done when you exercise (on a treadmill or exercise bike) This helps to assess the severity of the narrowing of the coronary arteries which causes angina Ambulatory ECG This is where you wear a small monitor which constantly records your heart rhythm This test records the electrical activity of your heart when you are walking about (ambulatory) and doing your normal activities It aims to detect abnormal heart rhythms that may 'come and go' The electrical activity is usually recorded for 24-48 hours 10 | P a g e Pauses of to seconds normally occur in healthy adults during sleep and occasionally in patients with increased vagal tone or hypersensitive carotid sinus disease Causes of sinus arrest :  Fibrosis and idiopathic degeneration of SA node  Increased vagal tone  Digoxin , quinidine, procainamide and salicylates  Excessive doses of beta- blockers and many other causes Sinus Arrest are usually asymptomatic but ,the Symptomatic patient will classically present to you as Recurrent dizziness, syncope & unexplained falls Asymptomatics usually don’t require treatment In any pathology in which asymptomatic patients don’t require treatment , you must educate your patient about his condition and lifestyle modifications In symptomatic, not a single Pharmacological agent has been proven to provide long-term effectiveness, so Permanent pacemaker implantation is generally considered an effective treatment 46 | P a g e CHAPTER : ATRIO -V ENTRICULAR ARRYTHMIAS ATRIAL TACHYCARDIA Atrial tachycardia is a rhythm disturbance that arises in the atria A rapid atrial rate overrides the SA node and become the dominant pacemaker Some st wave and t wave abnormalities may be present Rate : 150-250 bpm (In this ECG – Appro 200 bpm) Rhythm : Regular P wave : Normal but differs in shape from sinus P waves PR interval : May be short (.12sec) in rapid rates QRS : Normal (0.06-0.10 sec) but can be aberrant at times The rapid rate shortens diastole  resulting in a loss of atrial kick  reduced cardiac output  reduced coronary perfusion  ischemic myocardial changes  multiorgan failure due to underperfusion – most affected is Brain Patients presents to you with : Rapid regular pulse , Dyspnea, dizziness, light-headedness, fatigue, or chest pressure In tachycardic episodes - Sudden onset of palpitations & the Warm-up phenomenon 47 | P a g e (Tachycardia gradually speeds up soon after onset) Cardiac conditions that can cause atrial tachycardia include :  MI , Cardiomyopathy , Congenital anomalies  Wolff-Parkinson-White syndrome , Valvular heart disease  Cor pulmonale (Right Ventricular failure due to pathology in lungs or pulmonary vessels)  Hyperthyroidism , Systemic hypertension , Digoxin toxicity Treatment aims to control the rate with the helps of BBs & CCBs For the patients who are not managed by drugs : Cardioversion , Radiofrequency catheter ablation, Surgical ablation 48 | P a g e MULTIFOCAL ATRIAL TACHYCARDIA It is a type of wandering atrial pacemaker (discussed later) which is associated with ventricular rate > 100 bpm In MAT , Number of different clusters of cells outside of the SA node take over control of the heart rate.To distinguish it from Atrial fibrillation , see the presence of recognizable P wave Rate : Fast (>100 bpm) Rhythm : Irregular P wave : Atleast different forms , which are determined by the focus in the atria PR interval : Variable , depends on the focus QRS : Normal MAT is commonly seen in patients with Chronic Obstructive pulmonary disease but may also occur in acute myocardial infarction , Metabolic disorders & endocrinopathies Patients will presents to you with the primary pathology symptoms + Symptoms of atrial tachycardia Treat the underlying cause of MAT Pharmacological management by Calcium channel blockers (first line of treatment) , Magnesium sulfate , Beta blockers Rarely it can be Refractory of pharm Rx , so at that time AV junctional radiofrequency ablation and permanent pacemaker Implantation should be considered 49 | P a g e ATRIAL FLUTTER It is characterized by atrial rates of 250-400 beats/min with some degree of AV Block AV node conduct impulses to the ventricles at 2:1 , 3:1 $:1 or greater ratio Rarely it can also be 1:1 Degree of AV block may be consistence or variable Rate : Atrial 250-350 bpm , Ventricular : Slow or fast Rhythm :Usually regular but may be variable P wave : Waves have saw tooth appearance PR interval :Variable QRS : usually normal , but may appear widened if flutter waves are buried in QRS Originating in a single atrial focus, this rhythm results from circus reentry and possibly increased automaticity On an ECG, the P waves lose their distinction due to the rapid atrial rate The waves blend together in a sawtoothed appearance and are called flutter waves, or f waves Atrial flutter may be caused by conditions that enlarge atrial tissue and elevate atrial pressure Found in patients with severe mitral valve disease, hyperthyroidism, pericardial disease, & primary myocardial disease 50 | P a g e Clinical note : Patient usually use to be asymptomatic , signs and symptom depends on ventricular response rate Patient will typically have decreased cardiac output , Palpitations , Fatigue or poor exercise tolerance , Mild dyspnea , Presyncope The pulse may be regular or slightly irregular , Hypotension is possible, but normal blood pressure is more commonly observed Tachycardia may or may not be present, it depends on the degree of AV block associated with the atrial flutter activity Atrial flutter and sinus tachycardia Whenever you see sinus tachycardia with a rate of 150 beats/minute, take another look That rate is a common one for atrial flutter with 2:1 conduction Look closely for flutter waves, which may be difficult to see if they’re hidden in the QRS complex You may need to check another lead to clearly see them Treatment aim to Control the ventricular rate (BBs , CCBs) to prevent Clot formation by anticoagulants Also done Restoration of sinus rhythm (cardioversion or RFA )Ablations will minimize the usage of anticoagulant drugs and its toxicity 51 | P a g e ATRIAL FIBRILLATION Characterized by an irregular and often rapid heartbeat Rapid , erratic electrical discharge comes from multiple ectopic foci in the atrium No organized atrial contraction are detectable Rate : Atrial : 350 bpm or greater , ventricular rate : Slow or Fast Rhythm : Irregular P wave : No recognizable P wave , Chaotic atrial activity PR interval : None (because there is no recognizable P wave) QRS : Normal (because ventricles were not affected) A-fib is usually a chronic arrhythmia associated with underlying heart disease They are never considered normal Signs and symptoms depend on ventricular response rate 90% of AF episodes may not cause symptoms, Many patients experience a wide variety of symptoms, including palpitations, dyspnea, fatigue, dizziness, angina, and decompensated heart failure 52 | P a g e The irregular conduction of impulses through the AV node produces a characteristic irregularly irregular ventricular response If you see R waves that look irregularly irregular, suspect atrial fibrillation Atrial fibrillation can occur : Following cardiac surgery, By long-standing hypotension, Pulmonary embolism, Hyperthyroidism , Acute MI, Pericarditis, Hypoxia and other, Catecholamine release during exercise may also trigger the arrhythmia A patient with atrial fibrillation is at increased risk for developing atrial thrombus and systemic arterial embolism Because the atria don’t contract, blood may pool on the atrial wall, and thrombi can form , which can dislodge and embolized any small vessel leading to infarction of the particular structure that vessel supplies Treatment : Anticoagulation (Prevent embolism) Control rate by : B-blockers , Calcium channel blockers , or digoxin  Acute onset (