Interpreting ECGs: A Practical Approach

Cover
Title Page
Copyright Page
About the Author
Dedication
Contents
Preface
Features to Help You Study and Learn
Section 1: Preparatory
	Chapter 1: Anatomy and Electrophysiology of the Heart
		The Electrocardiogram
			How It Works
		The Circulatory System
		Anatomy of the Heart
			Shape and Position of the Heart
			The Pericardial Sac
			The Heart Wall
			The Internal Heart
		Cells of the Heart
			Myocytes
			Pacemaker and Electrical Conducting Cells
		The Heart’s Conductive Pathway
			SA Node
			AV Node
			Bundle of His and Right and Left Bundle Branches
			Purkinje Fibers
		The Heart’s Blood Supply
			Right Coronary Artery
			Left Main Coronary Artery
			Coronary Veins
		Physiology of the Heart and Circulation
			The Cardiac Cycle
			Cardiac Output
			Blood Pressure
			Blood Flow through the Atria
			Initiation of Impulse in the SA Node
			Atrial Depolarization and Contraction
			Conduction through the AV Node
			Conduction through the His-Purkinje System
			Ventricular Depolarization and Contraction
			Atrial and Ventricular Repolarization
			Alternate Pacemaker Sites
		Influences on the Heart and Circulatory System
			The Autonomic Nervous System
			Sympathetic Nervous System
			Parasympathetic Nervous System
			Increased Myocardial Oxygen Needs
		Nerve Impulse Generation and Muscle Contraction
			Polarized State
			Depolarization
			Repolarization
			Refractory Periods
			Impulse Generation of the SA Node
			Depolarization and Repolarization of the Myocytes
	Chapter 2: The Electrocardiogram
		The Electrocardiogram and ECG Machines
		ECG Lead Wires and Electrodes
			Lead Wires
			Electrodes
		Heart’s Normal Electrical Activity
		ECG Leads
			Bipolar/Unipolar Leads
		Planes of the Heart and Lead Placement
			Frontal Plane
			Horizontal Plane
			Putting the Views Together
			15- and 18-Lead ECGs
		Displays and Printouts
			Reading Printouts
Section 2: The Nine-Step Process
	Chapter 3: Analyzing the Electrocardiogram
		Characteristics of the Normal ECG
		Analyzing the Electrocardiogram Using the
 Nine-Step Process
			Step 1: Heart Rate
			Step 2: Regularity
			Step 3: P Waves
			Step 4: QRS Complexes
			Step 5: PR Intervals
			Step 6: ST Segments
			Step 7: T Waves
			Step 8: QT Intervals
			Step 9: U Waves
			Flexibility in the Nine-Step Process
		Dysrhythmia and Cardiac Condition Characteristics
		Analyzing the ECG
			Analyzing the Rhythm Strip
			Analyzing the 12-Lead Tracing
		Calibrating the ECG
		Artifact
	Chapter 4: Heart Rate
		Importance of Determining the Heart Rate
			Quick Check of the Heart Rate
			Heart Rates Seen with Various Dysrhythmias
		Methods of Determining Heart Rate
			6-Second Interval ×10 Method
			300, 150, 100, 75, 60, 50 Method
			1500 Method
			Rate Calculators
		Counting Both the Atrial and Ventricular Rates
		Normal, Slow, and Fast Rates
			Slow Rates—Bradycardia
			Fast Rates—Tachycardia
			Stable or Unstable, Narrow or Wide
	Chapter 5: Regularity
		Importance of Determining Regularity
			Quick Check of Regularity
		Methods of Determining Regularity
			Paper and Pen Method
			Caliper Method
			Counting the Small Squares Method
			Using a Rate Calculator
		Types of Irregularity
			Occasionally or Very Irregular
			Slightly Irregular
			Irregularity Caused by Sudden Changes in the Heart Rate
			Irregularly (Totally) Irregular
			Patterned Irregularity
			Irregularity Caused by Varying Conduction Ratios
	Chapter 6: P Waves
		Importance of Determining the P Waves
		Examining the P Waves
			Normal P Waves
		Identifying and Characterizing Abnormal P Waves
			Peaked, Notched, or Enlarged Sinus P Waves
			Atrial P Waves
			Varying Atrial P Waves
			Flutter and Fibrillatory Waves
			Inverted and Absent P Waves
			More P Waves than QRS Complexes
	Chapter 7: QRS Complexes
		Importance of Examining the QRS Complexes
		Examining the QRS Complexes
			Measuring QRS Complexes
		Variations in the QRS Configuration
		QRS Complexes in Different Leads
		Where We See Normal QRS Complexes
		Abnormal QRS Complexes
			Tall and Low-Amplitude QRS Complexes
			Wide QRS Complexes of Supraventricular Origin
			Wide, Bizarre-Looking QRS Complexes of Ventricular Origin
			Absent QRS Complexes
	Chapter 8: PR Intervals
		Importance of Determining the PR Intervals
		Characteristics of Normal PR Intervals
			Measuring the PR Intervals
		PR Intervals That Are Different
			Shorter PR Intervals
			Longer PR Intervals
			Varying PR Intervals
			Absent or Not Measurable PR Intervals
			Constant PR Intervals Seen with More P Waves
	Chapter 9: ST Segments, T Waves, QT Intervals, and U Waves
		Analyzing the Specific Waveforms, Segments, and Intervals
		Normal and Abnormal ST Segments
			Normal Characteristics
			Measuring the ST Segments
			Abnormal ST Segments
		Normal and Abnormal T Waves
			Normal Characteristics
			Measuring the T Waves
			Abnormal T Waves
		Normal and Abnormal QT Intervals
			Normal Characteristics
			Measuring the QT Interval
			Abnormal QT Intervals
		Normal and Abnormal U Waves
			Normal Characteristics
			Abnormal U Waves
		Section 2 Practice Makes Perfect
	Chapter 10: Heart Disease
		Defining Heart Disease
		Risk Factors of Heart Disease
			Age, Gender, and Family History
			Smoking and Alcohol Intake
			Poor Diet, Obesity, and Physical Inactivity
			High Blood Pressure
			High Blood Cholesterol Levels
			Diabetes
			Stress and “Type A” Personalities
			Poor Hygiene
		Complications of Heart Disease
			Dysrhythmias
			Angina
			Myocardial Infarction
			Dilation and Hypertrophy
			Heart Failure
			Cardiogenic Shock
			Stroke
			Aneurysm
			Peripheral Artery Disease
			Pulmonary Embolism
			Sudden Cardiac Arrest
		Types of Heart Disease
			Coronary Artery Disease
			Myocardial Ischemia
			Myocardial Injury
			Myocardial Infarction
			Cardiomyopathy
			Arrhythmogenic Right Ventricular Dysplasia
			Heart Infection
			Rheumatic Fever
			Valvular Heart Disease
			Congenital Heart Defects
Section 3: Origin and Clinical Aspects of Dysrhythmias
	Chapter 11: Overview of Dysrhythmias
		The Heart’s Normal Electrical Activity
		Dysrhythmias
		The Effects of Dysrhythmias
		Types of Dysrhythmias
			Bradycardia
			Tachycardia
			Early (Premature) Beats
			Dropped Beats or QRS Complexes
			Irregularity
		Causes and Mechanisms of Dysrhythmias
			Increased Parasympathetic Tone
			Myocardial Hypoxia, Injury, and Infarction
			Increased Automaticity
			Reentry
			Triggered Beats
			Proarrhythmia
		Site of Origin
			Sinus Dysrhythmias
			Atrial Dysrhythmias
			Junctional Dysrhythmias
			Ventricular Dysrhythmias
			AV Heart Block
		Identifying Dysrhythmias
		Patient Assessment
			Primary Assessment (ABCDEs)
			Secondary Assessment
			Ongoing Assessment
		Treatment of Dysrhythmias
			Physical Maneuvers
			Electrical Therapy
			Medications
	Chapter 12: Sinus Dysrhythmias
		Rhythms Originating from the Sinus Node
		ECG Appearance of Sinus Rhythms
		Normal Sinus Rhythm
		Sinus Bradycardia
			Description
			Causes
			Effects
			ECG Appearance
			Treatment
		Sinus Tachycardia
			Description
			Causes
			Effects
			ECG Appearance
			Treatment
		Sinus Dysrhythmia
			Description
			Causes
			ECG Appearance
			Treatment
		Sinus Arrest
			Description
			Causes
			Effects
			ECG Appearance
			Treatment
		Sinoatrial Exit Block
			Description
			Causes
			Effects
			ECG Appearance
			Treatment
		Sick Sinus Syndrome
			Description
			Causes
			Effects
			ECG Appearance
			Treatment
		Sinus Rhythm as the Underlying Rhythm
		Practice Makes Perfect
	Chapter 13: Atrial Dysrhythmias
		Rhythms Originating in the Atria
		Key Features of Atrial Dysrhythmias
			P Wave Appearance
			QRS Complex Appearance
			Effects of Atrial Dysrhythmias
		Premature Atrial Complexes
			Description
			Causes
			Effects
			ECG Appearance
			Differentiating Blocked PACs from Sinus Arrest
			Treatment
		Wandering Atrial Pacemaker
			Description
			Causes
			Effects
			ECG Appearance
			Treatment
		Atrial Tachycardia
			Description
			Causes
			Effects
			ECG Appearance
			Treatment
		Multifocal Atrial Tachycardia
			Description
			Causes
			Effects
			ECG Appearance
			Treatment
		Supraventricular Tachycardia
		Atrial Flutter
			Description
			Causes
			Effects
			ECG Appearance
			Treatment
		Atrial Fibrillation
			Description
			Causes
			Effects
			ECG Appearance
			Treatment
		Practice Makes Perfect
	Chapter 14: Junctional Dysrhythmias
		Dysrhythmias Originating in the Atrioventricular Junction
		Key Features of Junctional Dysrhythmias
			P Wave Appearance
			PR Interval
			QRS Complex Appearance
			Effects
		Premature Junctional Complex
			Description
			Causes
			Effects
			ECG Appearance
			Treatment
		Junctional Escape Rhythm
			Description
			Causes
			Effects
			ECG Appearance
			Treatment
		Accelerated Junctional Rhythm
			Description
			Causes
			Effects
			ECG Appearance
			Treatment
		Junctional Tachycardia
			Description
			Causes
			Effects
			ECG Appearance
		Atrioventricular Nodal Reentrant Tachycardia
			Description
			ECG Appearance
			Effects
		Preexcitation
			Wolff-Parkinson-White Syndrome
			Lown-Ganong-Levine Syndrome
		Atrioventricular Reentrant Tachycardia
			Description
			Appearance
			Effects
		Treatment of Supraventricular Tachycardia
		Practice Makes Perfect
	Chapter 15: Ventricular Dysrhythmias
		Dysrhythmias Originating in the Ventricles
		Key Features of Ventricular Dysrhythmias
			P Wave Appearance
			QRS Complex Appearance
			Effects
		Premature Ventricular Complexes
			Description
			Causes
			Effects
			ECG Appearance
			Treatment
		Ventricular Escape Beats
			Description
			Causes
			Effects
			ECG Appearance
			Treatment
		Idioventricular Rhythm
			Description
			Causes
			Effects
			ECG Appearance
			Treatment
		Accelerated Idioventricular Rhythm
			Description
			Causes
			Effects
			ECG Appearance
			Treatment
		Ventricular Tachycardia
			Description
			Causes
			Effects
			ECG Appearance
			Treatment
		Polymorphic Ventricular Tachycardia
			Description
			Causes
			Effects
			ECG Appearance
			Treatment
		Ventricular Fibrillation
			Description
			Causes
			Effects
			ECG Appearance
			Treatment
		Asystole
			Description
			Causes
			Effects
			ECG Appearance
			Treatment
		Pulseless Electrical Activity
			Description
			Causes
			Effects
			ECG Appearance
			Treatment
		Practice Makes Perfect
	Chapter 16: AV Heart Blocks
		Block of the Atrioventricular Node
		1st-Degree Atrioventricular Heart Block
			Description
			Causes
			Effects
			ECG Appearance
			Treatment
		2nd-Degree Atrioventricular Heart Block, Type I
			Description
			Causes
			Effects
			ECG Appearance
			Treatment
		2nd-Degree Atrioventricular Heart Block, Type II
			Description
			Causes
			Effects
			ECG Appearance
			Treatment
		3rd-Degree Atrioventricular Heart Block
			Description
			Causes
			Effects
			ECG Appearance
			Treatment
		Atrioventricular Dissociation
			Description
			Causes
			Effects
			ECG Appearance
			Treatment
		Practice Makes Perfect
	Chapter 17: Pacemakers and Implanted Cardioverter-Defibrillators
		Pacemakers and Implantable Defibrillators
		Temporary Pacemakers
			Epicardial Pacing
			Transvenous Pacing
		Permanent Pacemakers
			Uses
		Permanent Pacemaker Components
			Generator
			Lead Wire(s)
		Function of Permanent Pacemakers
			Pacing Modes
			Output
			Sensitivity
			Refractory Period
			Rate Adaptation
			Coding System
			Cardiac Resynchronization Therapy
		Appearance of the Paced ECG
			Unipolar vs. Bipolar Systems
		Pacemaker Failure and Complications
			Failure to Capture
			Failure to Pace
			Failure to Sense
			Oversensing
			Pacemaker-Mediated Tachycardia
			Complications of Pacemakers
		Implantable Cardioverter-Defibrillators
			Pulse Generator
			Electrode Wires
			Recognition of Ventricular Dysrhythmias
			Therapies Provided by the ICD
			Provider Safety
		Practice Makes Perfect
Section 4: 12-Lead ECGs
	Chapter 18: Overview of 12-Lead ECGs and Electrical Axis
		The 12-Lead ECG
			Views
		Limb Leads
			Leads I, II, and III
			Leads aVR, aVL, and aVF
		Precordial Leads
			Leads V1, V2, V3
			Leads V4, V5, V6
		ECG Views of the Heart
			Contiguous Leads
		Analyzing the 12-Lead ECG
		Electrical Axis and the ECG
			Vectors
			Mean Instantaneous Vector
			Waveform Direction
			Ventricular Depolarization and Mean QRS Axis
		Determining the Electrical Axis
			Hexaxial Reference System
		Altered QRS Axis
		Causes of Altered Electrical Axis
		Practice Makes Perfect
	Chapter 19: Myocardial Ischemia, Injury, and Infarction
		Coronary Circulation
			Right Coronary Artery (RCA)
			Left Coronary Artery (LCA)
		The ECG Waveforms
			Q Waves
			Normal ST Segments
			Normal T Waves
		ECG Indicators of Ischemia, Injury, and Infarction
			T Wave Changes
			ST Segment Changes
			STEMI and NSTEMI
			Q Wave Changes
			Left Bundle Branch Block
			Reciprocal Changes
			ECG Evolution during Myocardial Infarction
			MI—Age Indeterminate
		Criteria for Diagnosing Myocardial Infarction
			Clinical History
			Serum Cardiac Markers
			ECG Findings
		Identifying the Myocardial Infarction Location
			Septal Wall Infarction
			Anterior Wall Infarction
			Lateral Wall Infarction
			Anterolateral Wall Infarction
			Extensive Anterior Wall Infarction
			Inferior Infarction
			Posterior Wall Infarction
			Right Ventricular Infarction
		Treatment of Myocardial Infarction
			Right Ventricular Infarction Treatment
		Practice Makes Perfect
	Chapter 20: Bundle Branch Block
		Ventricular Conduction Disturbances
		The Bundle Branches
		Bundle Branch Block
			ECG Leads Used to Identify Ventricular Conduction Disturbances
			Right Bundle Branch Block
			Left Bundle Branch Block
			Incomplete Bundle Branch Block
			Nonspecific Intraventricular Conduction Defect
		Fascicular Block
			Left Anterior Fascicular Block
			Left Posterior Fascicular Block
			Bifascicular and Trifascicular Blocks
		Identifying MI and/or Hypertrophy in the Presence of Bundle Branch Block
		Treatments of Bundle Branch Block
		Inherited Conditions That Mimic Right Bundle Branch Block
			Brugada Syndrome
			Arrhythmogenic Right Ventricular Dysplasia (AVRD) (ARVC)
		Practice Makes Perfect
	Chapter 21: Atrial Enlargement and Ventricular Hypertrophy
		ECG Changes Used to Identify Enlargement and Hypertrophy
		Atrial Enlargement
			Right Atrial Enlargement
			Left Atrial Enlargement
		Ventricular Hypertrophy
			Right Ventricular Hypertrophy
			Left Ventricular Hypertrophy
		ST Segment and T Wave Changes
			Hypertrophic Cardiomyopathy
		Practice Makes Perfect
	Chapter 22: Other Cardiac Conditions and the ECG
		Pericarditis
			ECG Changes
		Pericardial Effusion
			ECG Changes
		Pulmonary Embolism
			ECG Changes
		Electrolyte Imbalance
			Hyperkalemia
			Hypokalemia
			Calcium Disorders
		Drug Effects and Toxicity
			Digoxin
			Other Medications
		Practice Makes Perfect
Section 5: Review and Assessment
	Chapter 23: Putting It All Together
		Using the Nine-Step Process and Deductive Analysis
		Step 1: Heart Rate
			Slow Rate
			Normal Rate
			Fast Rate
		Step 2: Regularity
			Regular Rhythms
			Irregular Rhythms
		Step 3: P Waves
			Normal P Waves
			Abnormal P Waves
		Step 4: QRS Complexes
			Normal QRS Complexes
			Abnormal QRS Complexes
		Step 5: PR Intervals
			Normal PR Intervals
			Abnormal PR Intervals
		Step 6: ST Segments
			Normal ST Segments
			Abnormal ST Segments
		Step 7: T Waves
			Normal T Waves
			Abnormal T Waves
		Step 8: QT Intervals
			Normal QT Intervals
			Abnormal QT Intervals
		Step 9: U Waves
		So Why Do It
		Practice Ruling Out Dysrhythmias and Conditions
		Practice Makes Perfect
Appendix A
Glossary
Index
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	L
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	N
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