Core
Results:
JT Interval: Basics
Key Points: The JT interval isolates ventricular repolarization by removing QRS duration from the QT. JT = QT − QRS. It is most useful when the QRS is wide, where…
PR Interval: Basics
Key Points: Definition: PR interval runs from P-wave onset to the first ventricular deflection (start of QRS). It reflects atrial depolarization plus conduction through the AV node and His-Purkinje system….
RR Interval: Basics
Key Points: The RR interval is the time between consecutive R waves. It is the most practical way to assess rate and regularity. RR is the backbone of rhythm interpretation:…
Waveforms, Segments, & Intervals: Basics
Key Points: Every ECG tracing is built from waveforms (deflections), segments (baseline portions between waveforms), and intervals (time that include waveforms plus segments). Waveforms describe electrical events (depolarization or repolarization)….
STAT ECG 101: The Acute Care ECG Workflow
Key Points: The ECG is the fastest bedside test for rhythm, conduction, ischemia, and tox-metabolic disease. It only saves lives when interpreted systematically and acted on. In acute care, the…
Hypokalemic Periodic Paralysis
Key Points: Definition: Hypokalemic periodic paralysis (HPP) is a rare disorder characterized by episodic, reversible flaccid muscle weakness associated with a shift of potassium from the extracellular space into skeletal…
STEMI in the Presence of Baseline ECG Abnormalities
Key Points: Baseline ECG abnormalities do not protect patients from occlusion MI. They increase miss rates because they distort the ST segment and T waves. The core question is not…
Lateral and High-Lateral STEMI: Criteria, Localization, and Pitfalls
Key Points: Lateral and high-lateral STEMI often present with subtle ST elevation and are commonly missed or labeled as nonspecific ST-T changes. Small-appearing ECG changes may represent true coronary occlusion…
Inferior STEMI: Criteria, RV Involvement, and Pitfalls
Key Points: Inferior STEMI is the most common STEMI subtype and is frequently complicated by right ventricular and posterior involvement. Inferior occlusion may present with classic ST elevation, subtle ischemic…
Anterior STEMI: Criteria, Localization, and Pitfalls
Key Points: Anterior STEMI represents large myocardial territory at risk and carries the highest mortality among STEMI subtypes. Early recognition and reperfusion are critical. LAD occlusion may present with classic…
Posterior STEMI: Criteria & Pitfalls
Key Points: High risk of missed diagnosis. Isolated posterior occlusion MI is frequently missed because ST elevation is absent on the standard 12-lead ECG. Instead, posterior infarction most often presents…
STEMI vs LV Aneurysm: DDx
Key Points: LV aneurysm pattern is a post MI scar pattern with persistent ST elevation in the prior infarct territory, usually with pathologic Q waves and a stable, non evolving…
STEMI Mimics: DDx
Key Points: ST elevation is a pattern, not a diagnosis. STEMI represents one cause of ST elevation and requires correlation with ECG morphology, distribution, evolution, and clinical context. Most ED…
STEMI vs Severe Hyperkalemia: DDx
Key Points: Severe hyperkalemia is a true ECG chameleon. It can produce ST elevation, wide QRS complexes, axis shifts, and conduction blocks that closely mimic STEMI or ventricular tachycardia. New…
STEMI vs Acute Pericarditis: DDx
Key Points: Start by looking for STEMI, not pericarditis. The safest workflow is to actively search for occlusion MI features first, then use pericarditis features as supportive evidence. Reciprocal ST…
STEMI vs Takotsubo Cardiomyopathy: DDx
Key Points: Takotsubo (stress) cardiomyopathy is a transient, non-ischemic LV dysfunction—classically apical ballooning with basal hyperkinesis—often after emotional or physical stress. Presentation mimics occlusion MI (chest pain, ECG changes, elevated…
Earliest Evidence of Occlusion MI
Key Points: ACS is dynamic. Coronary arteries can occlude, partially reperfuse, and re-occlude over minutes to hours, and the ECG can show these shifts before biomarkers do. The earliest actionable…
ECG Evidence of Reperfusion After Occlusion
Key Points: Reperfusion and re-occlusion can occur spontaneously or after therapy. The ECG often reflects these changes earlier than symptoms. Most useful bedside ECG marker of reperfusion is ST-segment resolution…
Early Reciprocal Changes: OMI Pattern
Key Points: STEMI criteria alone miss some acute coronary occlusions, so look for subtle “occlusion clues,” not just traditional STEMI criteria cutoffs. Minor ST elevation under 1 mm paired with…
de Winter T Waves: STEMI Equivalent Pattern
Key Points: STEMI Equivalent: The de Winter ECG pattern is an uncommon STEMI equivalent indicative of an unstable proximal occlusion of the LAD (left anterior descending coronary artery). Treat the…
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
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