Contents Section 1 “How To” Introduction & Helpful Hints 9 Applications of the Electrocardiogram 10 Circulation System 11 Conduction System 12 Five Physiologic Properties of Cardiac Muscle 13 Electrocardiogram-Definition 14 What is Lead, Anyway? 15 Generation of the Electrocardiogram 16 Electrocardiographic Recording Technique 17 ECG Paper & Standardization 19 Calculating the Heart Rate 20 Measuring the P-QRS-T 22 Canine ECG Normal Values 24 Feline ECG Normal Values 25 Quick & Dirty Guide to ECG Enlargements & Bundle Branch Blocks 26 Classification of Arrhymias 27 Building Blocks for Arrhythmia Interpretation 28 Interpreting Arrhythmias-the Easy Way 30 Section 2 Electrocardiographic Examples Normal Sinus Impulse Formation Normal Sinus Rhythm 34 Sinus Arrhythmia 36 Disturbances of Sinus Impulse Formation Sinus Bradycardia 38 Sinus Tachycardia 40 Disturbances of Supraventricular Impulse Formation Atrial Premature Complexes 44 Atrial Tachycardia 46 Atrial Fibrillation 48 Atrioventricular (AV) Junctional Premature Complexes & Tachycardia 50 Disturbances of Ventricular Impulse Formation Ventricular Premature Complexes 54 Ventricular Tachycardia 56 Ventricular Asystole 58 Ventricular Fibrillation 60 Disturbance of Impulse Conduction Sinus Arrest or Block 64 Sick Sinus Syndrome 66 Atrial Standstill 68 Ventricular Pre-Excitation & Wolff-Parkinson-White Syndrome 70 Secret to Atrioventricular Blocks 73 First-Degree Atrioventricular Block 74 Second-Degree Atrioventricular Block 76 Third-Degree Atrioventricular Block 80 Left Bundle Branch Block 82 Right Bundle Branch Block 84 Escape Rhythms Junctional & Ventricular Escape Rhythms 88 Miscellaneous Disturbances Pericardial Effusion (low voltage QRS Complexes & electrical alternans 92 ST Segments & T Wave Changes 94 Artifacts 96 Appendix Anti-Arrhythmic Drugs 100 Recommended Textbook Readings 104