Guide to Basic Electrocardiography

169 Pages·1990·10.35 MB·English

by  John Wagner Beasley M.D.

Guide to
Basic Electrocardiography
Guide to
Basic Electrocardiography
John Wagner Beasley, M.D., and
E. Wayne Grogan, Jr., M.D.
University of Wisconsin Medical School
Madison, Wisconsin
PLENUM MEDICAL BOOK COMPANY • NEW YORK AND LONDON
Library of Congress Cataloging-in-Publication Data
Beasley, John Wagner.
GUlde to basic electrocardiography I John Wagner Beasley and E.
Wayne Grogan, Jr.
p. cm.
Includes bibliographical references.
Includes index.
ISBN-13:978-0-306-43296-5 e-ISBN-13:978-1-4613-0517-0
DOI:l0.l0071978-1-4613-0517-0
1. Electrocardiography. [1. Electrocardiography.] I. Grogan,
E. Wayne. II. Title.
[DNLM: WG 140 B368g]
RC683.5.E5B375 1990
616. 1 '2'07547--dc20
DNLM/DLC
for Llbrary of Congress 90-7327
CIP
©1990 Plenum Publishing Corporation
233 Spring Street, New York, N.Y. 10013
Plenum Medical Book Company is an imprint of Plenum Publishing Corporation
All rights reserved
No part of this book may be reproduced, stored in a retrieval system, or transmitted
in any form or by any means, electronic, mechanical, photocopying, microfilming,
recording, or otherwise, without written permission from the Publisher
D
Preface
The purpose of this text is to provide a reference work ticular attention has been paid to the diagnosis of
covering basic electrocardiographic (EeG) patterns common rhythm problems.
and diagnoses in a succinct and useful format. The The contents are directed at the primary physi
book covers common adult EeG abnormalities and is cian in residency training or in practice, and a reason
organized according to the type of abnormality, able background knowledge of terminology and basic
rather than by specific disease or EeG diagnosis. De pathophysiology is assumed. Thus, certain topics,
tailed lists of possible causes for various EeG patterns such as a detailed discussion of electrophysiology, are
have been included wherever appropriate, and par- omitted for the sake of brevity. For a discussion of this
5
PREFACE 6
topic, complex or unusual rhythm patterns, and the have generally been selected as common examples of
advanced techniques of deciphering unusual rhythms abnormalities, often as they occur in concert with
and other uncommon abnormalities, the reader is re other abnormalities, rather than as pure "classic" ex
ferred to other, more detailed, texts. The techniques of amples of a single abnormality. Therefore, in many
performing an ECG are not covered here and the topic instances the examples given include commonly as
of children's ECGs is treated only briefly. A number of sociated abnormalities in addition to the one under
more detailed self-study and reference texts are avail discussion. They are thus representative of the reality
able, which the authors have found useful in the prep of clinical practice, where abnormalities only occa
aration of this text and in their clinical work. sionally occur in their pure, isolated, and classical
(1-5)
The ECG tracings included here as examples forms.
D
Contents
1. Introduction................................................................................. 15
2. A Way to Visualize the Electrocardiogram in Relation to the Heart. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
3. The Formal Reading of the Electrocardiogram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 25
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 26
The Description of the Electrocardiogram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 26
7
CONTENTS 8
The Anatomy of the Normal Tracing.................... .................. ...... .......... ...... 27
The Interpretation of the Electrocardiogram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 28
4. Indications for Performing an Electrocardiogram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 31
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 32
Screening. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 32
Hypertension............................................................ ........ ........ ..... 32
Coronary Artery Disease, Chest Pain, and Ischemia. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 33
Pericarditis and Myocarditis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 33
Palpitations, Syncope, and Arrhythmias. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 34
Valvular and Congenital Heart Disease . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 34
5. Abnormalities of Rhythm. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 37
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 38
Supraventricular Arrhythmias. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 39
Regular Supraventricular Rhythms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 40
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 40
Sinus Bradycardia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 40
Sinus Tachycardia. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 40
Atrial Tachycardias. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 41
Paroxysmal Supraventricular Tachycardias. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 42
Rhythms Seen with Wolff-Parkinson-White and Related Syndromes............ .. ............... 44
Atrial Flutter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 46
Junctional Rhythms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 49
Irregular Supraventricular Rhythms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 51
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 51
Sinus Arrhythmia. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 51
Premature Atrial Complexes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 51
Wandering Atrial Pacemaker (Multifocal Atrial Rhythm). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 55
Multifocal Atrial Tachycardia. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 55
Sinus Pauses and Sinus Arrest. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 58
Premature Junctional Complexes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 59
Atrial Fibrillation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 60
Irregularity and the Ashman Phenomenon .................................................... . 62
Atrial Fibrillation in Patients with WPW ...................................................... . 62
Regular Ventricular Rhythms ................................................................... . 64
Introduction ............................................................................... . 64
Ventricular Escape Rhythm .................................................................. . 64
Accelerated Idioventricular Rhythm .......................................................... . 65
Ventricular Tachycardia ...................................................................... . 66
Paced Rhythms ............................................................................. . 70
Irregular Ventricular Rhythms .................................................................. . 72
Introduction ............................................................................... . 72
Premature Ventricular Complexes ............................................................ . 72
Torsade de Pointes ............................................................................ . 77
Ventricular Fibrillation ....................................................................... . 78
Irregular Ventricular Paced Rhythms .......................................................... . 79
CONTENTS 9
CONTENTS 10
Capture as a Cause of Ventricular Irregularity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 80
Distinguishing Ventricular from Supraventricular Arrhythmias. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 83
Ventricular Rhythms and Atrioventricular Block. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 87
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 87
Mobitz Type I (Wenckebach) Second-Degree AV Block................ ........ ........ ........... 88
Mobitz Type II Second-Degree AV Block.............. ...................... ........ ........... 90
Third-Degree AV Block........................................ .. ............................. 92
6. Abnormalities of Conduction (Exclusive of Second- and Third-Degree
Atrioventricular Block). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 95
Abnormalities of the P-R Interval. ............................................................ " 96
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 96
First-Degree Atrioventricular Block. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 96
Abnormalities of the QRS Interval (Including Bundle Branch Blocks) ............................. " 98
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
Right Bundle Branch Block ................................................................... 100
Left Bundle Branch Block. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 102
Abnormalities of the Ventricular Intrinsicoid Deflection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 104
Nonspecific Intraventricular Conduction Delay ................................................. 104
Abnormalities of the Q-T Interval. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 106
7. Abnormalities of the Electrical Axis ........................................................... " 109
Introduction ................................................................................ " 110
Abnormalities of the P-Wave Axis ............................................................... 110
Abnormalities of the QRS Axis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 110
Left-Axis Deviation .......................................................................... 110
Left Anterior Fascicular Block ................................................................. 112
Right-Axis Deviation ......................................................................... 116
Left Posterior Fascicular Block. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 118
Indeterminate or Inconsistent Frontal Plane Axis ............................................... 120
Lead Placement Errors ..................................................................... " 122
Bifascicular and Trifascicular Blocks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
Abnormalities of the T-Wave Axis ............................................................. " 126
8. Abnormalities of the P Wave ................................................................... 127
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 128
The Tall P Wave. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 128
The Wide and/or Notched P Wave ................................. , ............................ 130
9. Abnormalities of the QRS Complex ............................................................. 133
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 134
Abnormally Low QRS Voltages ................................................................. 134
Abnormally High QRS Voltages. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 134
Ventricular Hypertrophy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 135
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 135
Left Ventricular Hypertrophy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 135
Right Ventricular Hypertrophy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 138
CONTENTS 11