ECG Interpretation Course – ECG Principles

Electrical Activity of the Heart
Electrocardiographic Language of Direction
Functions of an Electrocardiograph
How the ECG Machine Measures Current Direction
The Dipole Concept
The ECG of Ventricular Depolarization
The ECG of Ventricular Repolarization

Frontal Plane Hexaxial System
Plotting Vectors in the Hexaxial System
The Bipolar Limb Leads 1, 2 and 3
The Semicircle Method of Plotting Frontal Vectors
The Triaxial System I, II
The Unipolar Limb Leads

Placing the Chest Electrodes
Plotting Vectors with the Horizontal Plane Hexaxial System
How to Draw a Spatial Vector

The Normal Frontal Plane
Frontal Plane Indeterminate Axes
Effects of Age and Chest Shape on Frontal Plane QRS Axes
Normal Horizontal Plane QRS Ranges and Patterns
Horizontal Plane Normal T Ranges and Patterns
Horizontal Plane Normal P Ranges and Patterns
Pediatric P, QRS and T Directions
How to Recognize a Normal ECG

How to Produce a Good ECG Tracing – Basic Terminology
ECG Paper Speed and Time Markings
Applying the ECG Electrodes
Special ECG Leads
Patient and Bed Aspects
Lead Reversal and Lead Placement Artifacts
ECG: Artifacts

Left Ventricular Hypertrophy: The Problem of Increased Voltage
Frontal Plane LVH Criteria
Horizontal Plane LVH Criteria
Secondary LVH Criteria
Secondary Horizontal Plane LVH Criteria
The LVH Strain Pattern
Other Secondary T Criteria for LVH
Causes of Reduced Voltage
Acquired Ventricular Dilatation
Complete Bundle Branch Block and LVH
Volume Overloading of the Left Ventricle
The Significance of LVH on the ECG in Systolic Overloads

Frontal Plane Criteria for RVH
The Frontal Plane ECG in Emphysema or COPD
The Horizontal Plane ECG in Emphysema or COPD
Pectus Excavatum Versus Emphysema
Cachectic Heart Versus COPD
Horizontal Plane RVH Criteria
Initial V1 Negativity in RVH
S-T, T in the Right Precordium with RVH
Right Ventricular Systolic or Pressure Overloading
RVH of Pulmonary Stenosis
RBBB Pattern and Right Ventricular Overloading
RVH with Acute Pulmonary Embolism
Right Ventricular Diastolic Overload Pattern
Combined Ventricular Overloads and Differential Diagnosis of RVH

General Principles of Atrial Overload
The P Axis in Right Atrial Overload
The P Axis in COPD
P Pulmonale and Pseudo P Pulmonale in RA Overload
Horizontal Plane Signs of Right Atrial Overload
The Ta Wave and P-R Segment
Left Atrial Overload – Physiology and Etiologies
Wide, Notched P Waves (Intraatrial Block) in LA Overload
The P Axis in Left Atrial Overloads
Horizontal Plane Signs of Left Atrial Overload
Left Atrial Overload in Coronary Disease
Atrial Overloads in Atrial Arrhythmias

General Vector Rules in Myocardial Infarction
Direction of Initial Forces in Myocardial Infarction
Pathogenesis and Recognition of Necrosis Vectors
Recognition of a Necrosis Vector in the Frontal Plane
Recognizing Sites of Infarction by Frontal Plane Necrosis Changes
Horizontal Plane Necrosis Changes
Posterior Infarction
Normal Septal Versus Infarct Vectors in the Horizontal Plane
Uncovering Hidden Necrosis Vectors
Infarction in the Presence of LBBB
LBBB Initial Vectors Versus Infarct Vectors
Right Ventricular Overload Initial Vectors Mimicking Necrosis
Normal Q Wave in Lead 3 Versus Inferior Infarction

Hemiblocks or Divisional Blocks
Anterior Divisional Blocks
Left Axis Deviation With No Divisional Blocks
LVH and Anterior Divisional Blocks
Congenital Heart Disease With Possible ADBs
Posterior Divisional Blocks
Initial Vector in Divisional Blocks
Bifascicular and Trifascicular Blocks
Masquerading Bundle Branch Block
Postdivisional LBBB and QRS Axis
Trifascicular and Quadrifascicular Blocks or Delays
Etiologies and Prognoses of Bifascicular and Trifascicular Blocks
Lev’s Disease and Lenegre’s Disease
Periinfarction Blocks
Imitators of Classic Periinfarction Block

Electronic Pacemakers
Fixed-Rate Pacemakers
Demand Pacemakers
Three-Letter Pacemaker Code
Pacemaker Failure
Recognition of Implantion Site
Pacemaker Arrhythmias

Normal Repolarization Process
Genesis and Direction of the Injury Current
Frontal Plane Sites of Infarction
Horizontal Plane Sites
Significance of the Injury Current
Pericarditis Versus Infarction
Early Repolarization Versus Pericarditis
Left Ventricular Hypertrophy Strain Pattern Versus an Injury Current
Digitalis S-T Vector Versus the LVH Strain Pattern
Subendocardial Current of Injury
J Wave and Hypothermia
Exercise Testing
Criteria for an Ischemic S-T Response to Exercise Testing
How to Avoid False Positive Exercise Tests
How to Avoid False-Negative Exercise Tests for Ischemia
Vasospastic Angina Pectoris S-T Abnormalities

Direction of the Normal T Vector
QRS-T Angle
Shape and Duration of the Ischemic T
T Direction in Myocardial Infarction
T Negativity in Pericarditis
Postextrasystolic T Abnormalities

Tall T Wave Differential Diagnosis
Q-T Interval
Q-T and Hypercalcemia
Q-T and T in Hypocalcemia
U Wave
T Waves of Cardiomyopathies (Myocardial Infiltration, Fibrosis, Inflammation)
Notched T Waves
Digitalis Effect on the T Wave
T Wave In Hypothyroidism

Types of T Abnormalities and Syndromes Associated with a Normal Myocardium
Juvenile T Pattern
Neurotic Heart T Syndrome
Hyperventilation Syndrome T Abnormalities
S-T, T Abnormalities and the Valsalva Maneuver
Isolated T Negativity Syndrome
Benign T Negativity of Athletes
Cerebral Autonomic T Abnormalities
Prolapsed Mitral Valve Syndrome
Suspended Heart Syndrome
T Inversion of Schizophrenia
T Waves After Artificial Pacing

Initial Activation & the Septal Vector

Initial QRS Vector in Right Bundle Branch Block
Direction of the Terminal QRS Vector in Right Bundle Branch Block
Terminal Slowing in Right Bundle Branch Block
Complete and Incomplete Right Bundle Branch Block
Right Bundle Branch Block Pattern
Axis in Right Bundle Branch Block
Initial Vector in Left Bundle Branch Block
Mid-QRS Forces in Left Bundle Branch Block
Terminal QRS Forces and Intrinsicoid Deflections in Left Bundle Branch Block
Complete and Incomplete Left Bundle Branch Block
Secondary S-T, T Changes of Bundle Branch Block
Significance of Right and Left Bundle Branch Block

Wolff-Parkinson-White Syndrome
Eliciting the Accessory AV Bundle Type of Preexcitation
Delta Wave Masking and Mimicking Effects
Nonatrioventricular Accessory Bundle Preexcitation

Bundle of His Recordings

Reading Heart Rates
Sinus Tachycardia and Bradycardia
Automatic Control of the SA Node
Sinus Arrhythmia
Natural Pacemakers and the Transmembrane Action Potential
Phase 4
SA Block and Sinus Arrest
Sinus Node Dysfunction and the Sick Sinus Syndrome
AV Nodal Conduction Properties
First-Degree AV Block
Laddergram
Second-Degree AV Block
Complete AV Block
Supernormal Conduction
Escape Beats
Escape Pacemakers with Myocardial Infarction
Atrial Ectopic Beats and Pacemakers (Physiology of Automatic Cells)
P Wave Directions and Atrial Ectopic Sites
Premature Atrial Contractions
P’ in Junctional and Low Atrial Pacemakers
P’-R and P’-P Intervals
Hidden Ectopic P Wave Diagnosis
Aberrant Conduction with Premature Atrial Contractions
Right and Left Atrial Dissociation

Premature Ventricular Contractions
Site and Origin of PVCs
Timing of PVCs in the Cycle
Post-PVC Perfect Compensatory Pause
Interpolated PVCs
Group Beating
Concealed Extrasystoles
Possible Causes of PVCs (Reentry Theory)
Multiform Versus Multifocal PVCs
Ectopic Focus Theory
PVCs Versus Parasystole (Parasystole Defined)
Parasystole
Parasystolic Entrance and Exit Blocks
Capture and Fusion Beats
Reciprocal Beats
Ectopic Tachycardias
Atrial Fibrillation I, II
Atrial Flutter
Atrial Tachycardia
Isorhythmic Dissociation
Electrical Alternans
Ventricular Tachycardia
Mechanisms and Causes of Ventricular Tachycardia
Chronic VT
Differentiation of VT from Supraventricular Tachycardias
AV Dissociation
Bidirectional Tachycardia
Ventricular Flutter and Fibrillation