Core
Results:
Terminal QRS Distortion: OMI Pattern
Key Points: What it is: In V2 or V3, there is no S wave (the R does not descend below the PQ baseline) and no J wave (no notch/slur at…
Digoxin Toxicity
Key Points Narrow therapeutic window: Small dosing errors or renal decline can push serum digoxin above the safe range. Excess automaticity + AV block: Toxicity increases atrial and ventricular irritability…
QRS Axis Interpretation: Basics
Key Points: Definition: The QRS axis reflects the net direction of ventricular depolarization and is expressed in degrees on the frontal plane. Why It Matters: Axis assessment is a fast,…
Extreme Axis Deviation: Basics
Key Points Definition: Extreme axis deviation (aka “Northwest Axis”) occurs when the QRS axis is between –90° and ±180°. ECG Clue: QRS negative in Lead I QRS negative in Lead…
Left Axis Deviation: Basics
Key Points Definition: LAD occurs when the QRS axis is between –30° and –90°. ECG Pattern: QRS positive in Lead I QRS negative in Lead aVF Clinical Use: LAD can…
Indeterminate QRS Axis: Basics
Key Points Definition: An indeterminate QRS axis (also called “no man’s land”) occurs when the frontal QRS vector lies between –90° and ±180°, but no dominant direction is evident. ECG…
Right Axis Deviation: Basics
Key Points Definition: Right Axis Deviation (RAD) occurs when the QRS axis is > +90°, typically up to +180°. ECG Criteria: Negative QRS in Lead I Positive QRS in Lead…
Right Axis Deviation: DDx
Top 3 Emergent Causes of New Rightward Axis Deviation: When you see new RAD in an adult, immediately consider life-threatening etiologies: Acute Right Heart Strain Pulmonary embolism until proven otherwise…
Normal QRS Axis
Key Points Normal Axis Range: –30° to +90° Lead I: QRS complex is positive Lead aVF: QRS complex is positive → This combination confirms a normal QRS axis Frontal plane…
Interval Interpretation
Key Points: Intervals are your ECG safety rails. Before you get seduced by ST segments and T waves, lock down PR, QRS, and QT/QTc. They frequently reveal the real danger…
Fusion Beats
Key Points Definition: A fusion beat occurs when two impulses — one from the normal conduction system (typically supraventricular) and one from an ectopic ventricular focus (e.g., during VT) —…
History of the “STAT ECG”
Key Points The ECG is a cornerstone of acute care medicine, offering immediate, non-invasive insight into cardiac function in critically ill patients. Its evolution spans over a century, from rudimentary…
Pseudonormalization of T Waves
Key Points Definition: Pseudonormalization is the apparent normalization of previously inverted T waves, often signaling reocclusion of a coronary artery that had recently reperfused. Mechanism: During reperfusion, ischemic T wave…
Sinus Tachycardia
Key Points Definition: Sinus tachycardia is a regular rhythm originating from the sinoatrial (SA) node, defined by a heart rate >100 bpm in adults or above age-adjusted norms in children….
Trifascicular Block
Key Points Definition: Trifascicular block describes ECG evidence of impaired conduction across all three fascicles: right bundle branch (RBB), left anterior fascicle (LAF), and left posterior fascicle (LPF). Common Usage:…
Slow Atrial Fibrillation
Key Points Definition: Atrial fibrillation with a slow ventricular response, usually < 60 bpm. ECG: Irregularly irregular rhythm, no discrete P waves, slow R-R intervals. Common causes: AV-nodal blockers (digoxin,…
Precordial Swirl: OMI Pattern
Key Points Definition: The precordial swirl sign refers to a rotational pattern of ST-segment abnormalities across the precordial leads, suggesting a dynamic and evolving occlusion myocardial infarction (OMI). It is…
Unifasicular Block
Key Points Definition: Unifascicular block refers to conduction delay or interruption in a single fascicle of the ventricular conduction system: the right bundle branch (RBB), left anterior fascicle (LAF), or…
QRS Voltage: Basics
Key Points: Definition: QRS voltage represents the amplitude (height) of the QRS complex on ECG, reflecting ventricular electrical activity during depolarization. High Voltage: Increased QRS voltage typically indicates ventricular hypertrophy—most…
Sodium Channel Blocker Toxicity
Key Points: Recognizing the Danger: Sodium channel blocker toxicity can present with a variety of ECG changes that are critical to recognize, especially in patients with altered mental status or…
ECG Tags
- 5th Universal Definition of MI
- A-Z
- ACS Mimics
- ACS-OMI
- Activation
- Acute MI
- Advanced Level Curriculum
- Annual ECG Competition
- Anterior OMI
- Anterior STEMI
- Approach
- Arrest
- Arrhythmia
- Arrhythmogenic Cardiomyopathy
- Artifact
- ARVC
- ARVD
- Atrial Parasystole
- Attending
- AV Block
- aVF
- aVL
- aVR
- Axis
- Barcelona
- Basics
- Bix Rule
- Board Review
- Bradyarrhythmia
- Cath Lab
- Chest Pain
- Clumped Beats
- Competition
- Conduction
- Core
- Core Level Curriculum
- Critical ECG Patterns
- Curriculum
- DDx
- Delta
- Devices
- Diagonal Branch Occlusion
- Differential Diagnoses
- Diffuse ST Elevation
- Documentation
- Early Repolarization
- ECG Interpretation
- ECG Localization
- ECG Variant
- Education/Teaching
- Electrolytes
- Emergencies
- Emergent Cath Lab Activation
- EMS
- Expert Level Curriculum
- Flutter
- Flutter Waves
- Foundations Level Curriculum
- Guidelines
- High-Lateral STEMI
- Hub
- Hyperacute T waves
- Hypercalcemia
- Hyperkalemia
- Hypermagnesemia
- Hypocalcemia
- Hypokalemia
- Hypomagnesemia
- Hyponatremia
- Hypothermia
- I
- II
- Index
- Inferior OMI
- Inferior STEMI
- Intervals
- Irregular
- Ischemia
- Ischemia & Infarction
- J point
- J Waves
- JT
- Junctional Rhythm
- Juvenile T wave
- LAD Occlusion
- Lateral STEMI
- LBBB
- LCx Occlusion
- Lead Placement
- Left Atrial Enlargement (LAE)
- Life Savers
- LV an
- LV Aneurysm
- LVAD
- Mastery Level Curriculum
- Metabolic
- MI
- Mimics
- Morphology
- Narrow QRS
- Occlusion MI
- OMI Pattern
- Orthodromic AVRT
- Osborn Waves
- P Wave
- Paced Rhythms
- Pacemaker/ICD
- Paramedics
- Pauses
- PE
- Pediatrics
- Pericardial
- Pericarditis
- PGY-1
- PGY-2
- PGY-3
- PGY-4
- Post-Arrest
- post-arrest STEMI
- Post-Cardiac Arrest
- Posterior Extension
- Posterior MI
- Posterior STEMI
- potpourri
- PR
- Preexcitation
- Premature Complexes
- Prolonged QT
- Pulmonary Embolism
- Pulse-Tapping Artifact
- PVCs
- Q Wave
- QRS
- QT
- R Waves
- RAD
- Rate
- RBBB
- RCA Occlusion
- Regular
- Reperfusion
- Rhythm
- Right Atrial Enlargement (RAE)
- RR
- S Waves
- S1Q3T3
- Segments
- Seizure
- Serial ECGs
- Sgarbossa
- Shock
- South African Flag Sign
- ST
- ST Depression
- ST Elevation
- STEMI
- STEMI Equivalent
- STEMI Mimics
- STEMI Negative OMI
- Stepwise
- Stroke
- Structural
- Students
- SVT
- Syncope
- T Wave Inversion
- T Waves
- Tachyarrhythmia
- Tachycardia
- Tamponade
- Terminal QRS Distortion
- Toxicology
- TP
- Traditional STEMI Criteria
- U Waves
- Unstable
- V1-V4
- V2
- V5
- V6
- Vectors
- Ventricular Repolarization
- Ventricular Rhythms
- Ventricular Tachycardia
- Voltage
- Waveforms
- Wide QRS
- Workflow
- WPW
© 2026 ECG Weekly. All rights reserved. | Terms of Use | Privacy Policy
Powered by the member(dev) platform
Loading...