Basic Electrocardiography Normal and abnormal ECG patterns - Part 1 pdf

[...]... the origin of normal ECG and the normal and abnormal ECG patterns The importance of surface ECG in the diagnosis of arrhythmias is not shown and will be done in another book We recommend consulting our textbook on clinical electrocardiography [1] and our Internet course (www.cursoecg.com) CHAPTER 3 Electrophysiological principles The origin of ECG morphology The origin of ECG morphology [1, 3–7] may be... transient abnormalities may be detected owing to a number of causes (hyperventilation, hypothermia, glucose or alcohol intake, ionic abnormalities, effect of certain drugs, etc.) Electrocardiography has become even more important than it was at the beginning In the twenty-first century, ECG is not only a technique used to 4 Usefulness and limitations of electrocardiography 5 diagnose an abnormal pattern,... (clockwise or anti-clockwise), represents a significant additional value Thanks to careful loop analysis, ECG morphologies may be better understood (Figures 1D, 4, 16 , 18 and 21) The sum of subendocardial and subepicardial TAP The other approach to understanding ECG morphology is based on the concept that the TAP of a cell or the left ventricle (considered as a huge cell that originates the human ECG) is equal... plane, upwards–downwards and right– left, and in horizontal plane, right–left and anterior–posterior) (Figure 3) Each 10 Chapter 3 of these loops has its maximum vector that is considered to be the sum of all instantaneous vectors (Figures 1 and 3) and expresses the magnitude and general direction of a loop Nevertheless, the morphology of a loop, especially its initial and terminal part as well as loop... ‘Let’s have an ECG recording done so that we may solve the problem’ It must be remembered that a high percentage of patients with coronary heart disease, in the absence of chest pain, show a normal ECG recording and that even in acute coronary syndromes ECG is normal or borderline in approximately 5 10 % of cases, and without symptoms especially in its early phase Furthermore, ECG may be normal months... subendocardial and subepicardial TAPs How this occurs is shown in Figure 10 (see the caption) This concept is useful for understanding how the ECG patterns of ischaemia and injury are generated, although these morphologies may also be explained by the ischaemic and injury vector concept (see sections ‘Electrocardiographic pattern of ischaemia’ and ‘Electrocardiographic pattern of injury’ in Chapter 11 ) The... cautious, and before considering this to be a non-specific abnormality, ischaemic heart disease, channelopathies (long QT, Brugada’s syndrome, etc.) or pre-excitation syndromes should be ruled out Therefore, it is necessary to read the ECG recordings while bearing in mind the clinical setting and, if necessary, taking sequential recordings In addition, normal variants may be observed in the ECG recording,... Usefulness and limitations of electrocardiography ECG is the technique of choice in the study of patients with chest pain, syncope, palpitations and acute dyspnoea, and is crucial for the diagnosis of cardiac arrhythmias, conduction disturbances, pre-excitation syndromes and channelopathies It is also very important for assessing the evolution and response to treatment of all types of heart diseases and other... system) (Figure 12 A) There are also three monopolar leads (VR, VL and VF) in the frontal plane (Figure 11 B) By adding these three leads to Bailey’s triaxial system, Bailey’s hexaxial system is obtained (Figure 12 B) How the projection of different vectors (or loops) gives different morphologies in leads I, II and III is depicted in Figure 11 C On a horizontal plane, there are six monopolar leads (V1 to V6)∗... greater part of a human ECG) are shown in a Figure 7 During depolarisation (phases 0 and 1 of TAP), positive charges move from outside to inside the cell, first through the fast channel of Na+ and later that of Ca2+ Na+ During repolarisation of the cell or left ventricle (phases 2 and 3 6 Electrophysiological principles 7 Conduction speed m/s 0 1 2 3 4 Sinus node Atrial muscle AV node 0.05 1. 7 0.02−0.05 . necrosis, 97 12 Miscellaneous, 11 7 Value of ECG in special conditions, 11 7 ECG pattern of poor prognosis, 11 7 ECG of electrical alternans, 11 7 Self-assessment, 12 1 References, 16 5 Index, 16 9 P1: OTE/SPH. review. First published 2007 1 2007 ISBN: 97 8 -1 -4 05 1- 7 57 0-8 Library of Congress Cataloging-in-Publication Data Bayes de Luna, Antonio. Basic electrocardiography : normal and abnormal ECG patterns / Antoni. P1: OTE/SPH P2: OTE BLUK096-Bayes de Luna June 7, 2007 18 :58 Basic Electrocardiography NORMAL AND ABNORMAL ECG PATTERNS i P1: OTE/SPH P2: OTE BLUK096-Bayes de Luna June 7, 2007 18 :58 Basic Electrocardiography NORMAL