ECG interpretation made incredibly easy!.

380 Pages·2011·10.478 MB·English

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Staff The clinical treatments described and recommended
in this publication are based on research and consulta-
tion with nursing, medical, and legal authorities. To the
Publisher best of our knowledge, these procedures reflect cur-
Chris Burghardt rently accepted practice. Nevertheless, they can’t be
considered absolute and universal recommendations.
Clinical Director
For individual applications, all recommendations must
Joan M. Robinson, RN, MSN be considered in light of the patient’s clinical condition
and, before administration of new or infrequently used
Clinical Project Manager
drugs, in light of the latest package-insert information.
Jennifer Meyering, RN, BSN, MS The authors and publisher disclaim any responsibility
Product Director for any adverse effects resulting from the suggested
procedures, from any undetected errors, or from the
David Moreau
reader’s misunderstanding of the text.
Product Manager
Jennifer K. Forestieri © 2011 by Lippincott Williams & Wilkins. All rights
reserved. This book is protected by copyright. No part
Editor of it may be reproduced, stored in a retrieval system, or
Tracy S. Diehl transmitted, in any form or by any means—electronic,
mechanical, photocopy, recording, or otherwise—
Art Director
without prior written permission of the publisher, except
Elaine Kasmer for brief quotations embodied in critical articles and
reviews and testing and evaluation materials provided by
Illustrator
publisher to instructors whose schools have adopted its
Bot Roda
accompanying textbook. Printed in China. For informa-
Design Assistant tion, write Lippincott Williams & Wilkins, 323 Norristown
Road, Suite 200, Ambler, PA 19002-2756.
Kate Zulak
Vendor Manager ECGIE5E11010
Beth Martz
Associate Manufacturing Manager Library of Congress Cataloging-in- Publication Data
Beth J. Welsh ECG interpretation made incredibly easy!. —
5th ed.
Editorial Assistants
p. ; cm.
Karen J. Kirk, Jeri O’Shea, Linda K. Ruhf Includes bibliographical references and index.
ISBN 978-1-60831-289-4 (pbk. : alk. paper)
1. Electrocardiography. 2. Heart—Diseases—
Nursing. I. Lippincott Williams & Wilkins.
[DNLM: 1. Electrocardiography—Nurses’
Instruction. 2. Arrhythmias, Cardiac— Nurses’
Instruction. WG 140 E172 2011]
RC683.5.E5E256 2011
616.1’207547—dc22
ISBN-13: 978-1-60831-289-4 (alk. paper)
ISBN-10: 1-60831-289-5 (alk. paper) 2010022956
iv
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Contents
Contributors and consultants vi
Not another boring foreword vii
Part I ECG fundamentals
1 Cardiac anatomy and physiology 3
2 Obtaining a rhythm strip 23
3 Interpreting a rhythm strip 43
Part II Recognizing arrhythmias
4 Sinus node arrhythmias 63
5 Atrial arrhythmias 87
6 Junctional arrhythmias 111
7 Ventricular arrhythmias 127
8 Atrioventricular blocks 153
Part III Treating arrhythmias
9 Nonpharmacologic treatments 175
10 Pharmacologic treatments 205
Part IV The 12-lead ECG
11 Obtaining a 12-lead ECG 239
12 Interpreting a 12-lead ECG 255
Appendices and index
Practice makes perfect 286
ACLS algorithms 304
Brushing up on interpretation skills 310
Look-alike ECG challenge 348
Quick guide to arrhythmias 359
Glossary 364
Selected references 366
Index 367
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Contributors and consultants
Diane M. Allen, RN, MSN, ANP, BC, CLS Karen Knight-Frank, RN, MS, CNS, CCRN, CCNS
Nurse Practitioner Clinical Nurse Specialist, Critical Care
Womack Army Medical Center San Joaquin General Hospital
Fort Bragg, N.C. French Camp, Calif.
Nancy Bekken, RN, MS, CCRN Marcella Ann Mikalaitis, RN, MSN, CCRN
Nurse Educator, Adult Critical Care Staff Nurse, Cardiovascular Intensive Care
Spectrum Health Unit (CVICU)
Grand Rapids, Mich. Doylestown (Pa.) Hospital
Karen Crisfulla, RN, CNS, MSN, CCRN Cheryl Rader, RN, BSN, CCRN-CSC
Clinical Nurse Specialist Staff Nurse: RN IV
Hospital of the University of Pennsylvania Saint Luke‘s Hospital of Kansas City (Mo.)
Philadelphia
Leigh Ann Trujillo, RN, BSN
Maurice H. Espinoza, RN, MSN, CNS, CCRN Clinical Educator
Clinical Nurse Specialist St. James Hospital and Health Center
University of California Irvine Medical Center Olympia Fields, Ill.
Orange
Rebecca Unruh, RN, MSN
Kathleen M. Hill, RN, MSN, CCNS-CSC Nurse Manager – Cardiac Intensive Care
Clinical Nurse Specialist, Surgical Intensive Unit & Cardiac Rehabilitation
Care Unit North Kansas City (Mo.) Hospital
Cleveland Clinic
Opal V. Wilson, RN, MA, BSN
Cheryl Kabeli, RN, MSN, FNP-BC, CNS-BC RN Manager, PC Telemetry Unit
Nurse Practitioner Louisiana State University Health Sciences
Champlain Valley Cardiothoracic Surgeons Center
Plattsburgh, N.Y. Shreveport
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Not another boring foreword
If you’re like me, you’re too busy to wade through a foreword that uses pretentious
terms and umpteen dull paragraphs to get to the point. So let’s cut right to the chase!
Here’s why this book is so terrific:
1. It will teach you all the important things you need to know about ECG interpretation.
(And it will leave out all the fluff that wastes your time.)
2. It will help you remember what you’ve learned.
3. It will make you smile as it enhances your knowledge and skills.
Don’t believe me? Try these recurring logos on for size:
Ages and stages identifies variations in ECGs related to patient age.
Now I get it offers crystal-clear explanations of complex procedures, such as how to
use an automated external defibrillator.
Don’t skip this strip identifies arrhythmias that have the most serious consequences.
Mixed signals provides tips on how to solve the most common problems in ECG
monitoring and interpretation.
I can’t waste time highlights key points you need to know about each arrhythmia for
quick reviews.
See? I told you! And that’s not all. Look for me and my
friends in the margins throughout this book. We’ll be there
to explain key concepts, provide important care reminders,
and offer reassurance. Oh, and if you don’t mind, we’ll be
spicing up the pages with a bit of humor along the way, to
teach and entertain in a way that no other resource can.
I hope you find this book helpful. Best of luck
throughout your career!
Joy
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Part I ECG fundamentals
1 Cardiac anatomy and physiology 3
2 Obtaining a rhythm strip 23
3 Interpreting a rhythm strip 43
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1
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Just the facts
In this chapter, you’ll learn:
(cid:2) the location and structure of the heart
(cid:2) the layers of the heart wall
(cid:2) the flow of blood to and through the heart and the struc-
tures involved in this flow
(cid:2) phases of the cardiac cycle
(cid:2) properties of cardiac cells
(cid:2) details of cardiac impulse conduction and their relation-
ship to arrhythmias.
A look at cardiac anatomy
Cardiac anatomy includes the location of the heart; the structure
of the heart, heart wall, chambers, and valves; and the layout and
The mediastinum
structure of coronary circulation.
is home to the heart.
Outside the heart
The heart is a cone-shaped, muscular organ. It’s located in the
chest, behind the sternum in the mediastinal cavity (or medi-
astinum), between the lungs, and in front of the spine. The heart
lies tilted in this area like an upside-down triangle. The top of
the heart, or its base, lies just below the second rib; the bottom
of the heart, or its apex, tilts forward and down, toward the left
side of the body, and rests on the diaphragm. (See Location of the
pediatric heart, page 4.)
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CARDIAC ANATOMY AND PHYSIOLOGY
4
The heart varies in size depending on the person’s body size,
but the organ is roughly 5(cid:2) (12.5 cm) long and 31/2(cid:2) (9 cm) wide, or Ages
about the size of the person’s fist. The heart’s weight, typically 9 and stages
to 12 oz (255 to 340 g), varies depending on the person’s size, age,
sex, and athletic conditioning. An athlete’s heart usually weighs
Location of the
more than that of the average person, and an elderly person’s
pediatric heart
heart weighs less. (See The older adult heart.)
Layer upon layer The heart of an infant is
positioned more horizon-
The heart’s wall is made up of three layers: the epicardium, myo-
tally in the chest cavity
cardium, and endocardium. (See Layers of the heart wall.) The
than that of the adult. As
epicardium, the outer layer (and the visceral layer of the serous
a result, the apex is at
pericardium), is made up of squamous epithelial cells overlying
the fourth left intercostal
connective tissue. The myocardium, the middle layer, makes up
space. Until age 4, the
the largest portion of the heart’s wall. This layer of muscle tis-
sue contracts with each heartbeat. The endocardium, the heart’s apical impulse is to the
innermost layer, contains endothelial tissue with small blood ves- left of the mid clavicular
sels and bundles of smooth muscle. line. By age 7, the heart
A layer of connective tissue called the pericardium surrounds is located in the same
the heart and acts as a tough, protective sac. It consists of the position as the adult
fibrous pericardium and the serous pericardium. The fibrous peri- heart.
cardium, composed of tough, white, fibrous tissue, fits loosely
around the heart, protecting it. The fibrous pericardium attaches
to the great vessels, diaphragm, and sternum. The serous pericar-
dium, the thin, smooth, inner portion, has two layers:
(cid:129) the parietal layer, which lines the inside of the fibrous peri-
cardium
(cid:129) the visceral layer, which adheres to the surface of the heart.
Between the layers
The pericardial space separates the visceral and parietal layers
and contains 10 to 20 ml of thin, clear pericardial fluid that lubri-
cates the two surfaces and cushions the heart. Excess pericardial
fluid, a condition called pericardial effusion, compromises the
heart’s ability to pump blood. I rest on the
diaphragm.
Inside the heart
The heart contains four chambers—two atria and two ventricles.
(See Inside a normal heart, page 6.) The right and left atria serve
as volume reservoirs for blood being sent into the ventricles. The
right atrium receives deoxygenated blood returning from the body
through the inferior and superior vena cavae and from the heart
through the coronary sinus. The left atrium receives oxygenated
blood from the lungs through the four pulmonary veins. The inter-
atrial septum divides the chambers and helps them contract. Con-
traction of the atria forces blood into the ventricles below.
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A LOOK AT CARDIAC ANATOMY 5
Layers of the heart wall Ages
and stages
This cross section of the heart wall shows its various layers.
The older adult
heart
Pericardial space
As a person ages, his
heart usually becomes
Fibrous pericardium slightly smaller and loses
its contractile strength
and efficiency (although
Parietal pericardium
exceptions occur in peo-
ple with hypertension or
heart disease). By age
Epicardium
70, cardiac output at rest
has diminished by 30%
Myocardium
to 35% in many people.
Endocardium Irritable with age
As the myocardium of
the aging heart becomes
more irritable, extra sys-
toles may occur, along
with sinus arrhythmias
and sinus bradycardias.
In addition, increased
fibrous tissue infiltrates
the sinoatrial node and
Pump up the volume
internodal atrial tracts,
The right and left ventricles serve as the pumping chambers of the which may cause atrial
heart. The right ventricle receives blood from the right atrium and fibrillation and flutter.
pumps it through the pulmonary arteries to the lungs, where it picks
up oxygen and drops off carbon dioxide. The left ventricle receives
oxygenated blood from the left atrium and pumps it through the aorta
and then out to the rest of the body. The interventricular septum
separates the ventricles and also helps them to pump.
The thickness of a chamber’s walls depends on the amount of
high-pressure work the chamber does. Because the atria collect
blood for the ventricles and don’t pump it far, their walls are con-
siderably thinner than the walls of the ventricles. Likewise, the left
ventricle has a much thicker wall than the right ventricle because
the left ventricle pumps blood against the higher pressures in
the body’s arterial circulation, whereas the right ventricle pumps
blood against the lower pressures in the lungs.
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