Intervals
Results:
ECG Foundations: Vectors, Leads, & Activation
Key Points: An ECG records voltage differences over time. The ECG tracing is a plot where the horizontal axis is time and the vertical axis is voltage. Leads are viewpoints….
QT Interval: Basics
Key Points: Definition: QT is measured from QRS onset to T-wave end. It reflects total ventricular depolarization plus repolarization. Use QTc: QT varies with heart rate. Interpret QTc, not the…
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)….
Short QT Interval: DDx
Key Points: Short QT Interval: A QT interval is considered short when the corrected QT (QTc) interval is less than 350 ms. A short QT interval on the ECG can…
Prolonged QT Interval: DDx
Key Points: The QT interval reflects the time it takes for total ventricular depolarization and repolarization (Q wave onset to T wave end). QT prolongation increases the risk of torsades…
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…
Short QT Syndrome
Key Points Short QT Syndrome (SQTS) is a rare condition characterized by a shortened QT interval on the ECG, increasing the risk of atrial and ventricular arrhythmias, including sudden cardiac…
Congenital Long QT Syndrome
Key Points Congenital Long QT Syndrome (LQTS) is a group of genetic disorders characterized by a prolonged QT interval on ECG, leading to an increased risk of ventricular arrhythmias and…
Acquired Long QT Syndrome
Key Points Acquired Long QT Syndrome (LQTS) is the most common form of LQTS, resulting from medications, electrolyte disturbances, or underlying medical conditions. High-risk factors include the use of multiple…
ECG Tags
- A-Z
- ACS Mimics
- ACS-OMI
- Activation
- Advanced Level Curriculum
- Annual ECG Competition
- Anterior OMI
- Anterior STEMI
- Approach
- Arrest
- Arrhythmia
- Artifact
- Attending
- AV Block
- aVF
- aVL
- aVR
- Axis
- Basics
- Board Review
- Bradyarrhythmia
- Chest Pain
- Clumped Beats
- 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
- Foundations Level Curriculum
- Guidelines
- High-Lateral STEMI
- Hub
- Hyperacute T waves
- Hypercalcemia
- Hyperkalemia
- Hypermagnesemia
- Hypocalcemia
- Hypokalemia
- Hyponatremia
- Hypothermia
- I
- II
- Index
- Inferior OMI
- Inferior STEMI
- Intervals
- Irregular
- Ischemia
- Ischemia & Infarction
- J Waves
- JT
- LAD Occlusion
- Lateral STEMI
- LBBB
- LCx Occlusion
- Lead Placement
- Life Savers
- LV an
- LV Aneurysm
- Mastery Level Curriculum
- Metabolic
- Mimics
- 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-Cardiac Arrest
- Posterior Extension
- Posterior MI
- Posterior STEMI
- 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
- RR
- S Waves
- Segments
- Seizure
- Serial ECGs
- Shock
- ST
- ST Depression
- ST Elevation
- STEMI
- STEMI Equivalent
- STEMI Mimics
- STEMI Negative OMI
- Stepwise
- Stroke
- Structural
- Students
- SVT
- Syncope
- T Waves
- Tachyarrhythmia
- Tachycardia
- Tamponade
- Terminal QRS Distortion
- Toxicology
- TP
- Traditional STEMI Criteria
- U Waves
- Unstable
- V1-V4
- 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...