The electrocardiogram
(Redirected from ECG)
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Assistant Editor-in-Chief: Rim Halaby
Fundamentals of EKG
Basic Principles of Interpretation of an EKG
- Introduction to EKG
- How to read an EKG
- Normal sinus rhythm
- QRS axis and voltage
- Overall overview on electrocardiography
EKG Complexes
EKG Intervals
Abnormal Findings on the EKG
- Delta wave
- H wave
- K wave
- Low QRS voltage
- Nonspecific ST-segment and T-wave changes
- NSSTW changes
- Osborn wave
- P wave alternans
- Poor R wave progression
- PR interval alternans
- QRS complex alternans
- QT prolongation
- Retrograde P wave
- Sine wave pattern
- T wave alternans
- T wave inversion
- Tombstone ST elevation
- U wave
Conduction System
Tachyarrhythmias
Atrial Arrhythmias
- Atrial fibrillation
- Atrial flutter
- Ectopic atrial rhythm
- Multifocal atrial tachycardia (MAT)
- Paroxysmal atrial tachycardia (PAT) with block
- Premature atrial contractions (PAC)
- Sinus tachycardia
- Supraventricular tachycardia
- Wandering atrial pacemaker
Ventricular Arrhythmias
- Accelerated idioventricular rhythm
- Ventricular fibrillation
- Ventricular parasystole
- Ventricular tachycardia
- Wide complex tachycardias
Bradycardia and Conduction Abnormalities
- Sinus bradycardia
- First degree AV block
- Second degree AV block
- Complete or third-degree AV block
- Concealed conduction
- AV junctional rhythms
- Wolff-Parkinson-White syndrome
- Left bundle branch block
- Right bundle branch block
- Trifascicular block
EKG Findings in Diseases
Cardiac Hypertrophy and Dilatation
- Left ventricular hypertrophy (LVH)
- Right ventricular hypertrophy (RVH)
- Biventricular hypertrophy
- Left atrial enlargement
- Right atrial enlargement
- Biatrial enlargement
Acute Myocardial Infarction
Pre-excitation Syndromes
Cardiomyopathies
Congenital Heart Diseases
- Dextrocardia
- Atrial septal defect
- Ventricular septal defect
- Tetralogy of Fallot
- The heart in conjoined twins
- Congenital heart block
Inherited Diseases
Other Heart Diseases
EKG in Other Disease States
EKG Abnormalities in Electrolyte Disturbances
EKG Abnormalities in Normal Pregnancy (Physiological Changes)
- Left axis deviation
- Right axis deviation
- Q wave in lead III
- T wave inversion
- Increased R/S ratio in V1 and V2
- ST-segment depression (usually after anesthesia for C-section)
Drug Effects on the EKG
- Adenosine
- Amiodarone
- β-blockers
- Bretylium
- Calcium channel blockers
- Digitalis
- Disopyramide
- Encainide
- Flecainide
- Lidocaine
- Lithium
- Phenothiazines
- Phenytoin
- Procainamide
- Propafenone
- Quinidine
- Tocainide
- Tricyclic antidepressants
Technical Issues and Potential Errors in Interpretation
- EKG Artifacts
- EKG lead placement errors
- EKG in a patient with a pacemaker
- EKG in athletes
- Persistent juvenile T-wave pattern
- Postprandial EKG changes