Basics & Fundamentals
Latest
Pulse-Tapping Artifact
Key Points: Mechanical artifact caused by an ECG electrode sitting on top of a strong arterial pulse. Seen frequently in dialysis patients with AV fistulas. Can mimic serious pathology including…
Arrhythmogenic Cardiomyopathy (ACM)
Key Points: Definition & Terminology: Arrhythmogenic Cardiomyopathy (ACM), previously known as Arrhythmogenic Right Ventricular Cardiomyopathy/Dysplasia (ARVC/D), is an inherited disorder characterized by progressive fibrofatty replacement of the ventricular myocardium, predominantly…
Atrial Parasystole
Key Points: Atrial parasystole is a rare atrial rhythm in which an ectopic atrial focus fires at its own intrinsic rate, relatively protected from sinus-node reset by entrance block. The…
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…
Pacemakers: Basics
Key Points: Pacemakers treat bradyarrhythmias by delivering timed atrial, ventricular, or dual-chamber pacing when intrinsic activity is slow or absent. Know the major device types encountered in the ED: single-chamber,…
Himalayan T Waves
Key Points Tall, broad-based T–U fusion that looks like a mountain peak, usually from severe hypokalemia; think high torsades risk until proven otherwise. Hallmark is prolonged repolarization: QT appears long…
Pediatric ECG: Basics
Key Points Pediatric ECGs are not scaled-down adult ECGs. Right axis deviation, large R waves in V1, and T wave inversions in V1 to V3 are expected in healthy children….
Pseudo-Wellens Waves
Key Points: Pseudo-Wellens waves are anterior T-wave patterns that mimic the biphasic or deeply inverted T waves of true Wellens syndrome but are caused by non-LAD, non-ischemic physiology. These normal-variant…
Wellens Waves
Key Points Wellens waves are anterior precordial T wave abnormalities (biphasic or deeply inverted) most often in V2–V3, occasionally extending to V1 and V4–V6. They signal a high likelihood of…
T Wave Alternans
Key Points: Definition: Beat-to-beat alternation in T wave amplitude or morphology with stable P waves and QRS complexes. Significance: A visible marker of ventricular electrical instability. Strongly associated with torsades,…
Torsade de Pointes (TdP)
Key Points Definition: TdP is a specific subtype of polymorphic ventricular tachycardia associated with a prolonged QTc interval. It often presents with a “twisting” pattern on ECG but can be…
Ventricular Tachycardia (VT): Core Overview
Key Points VT is a ventricular-origin rhythm: ≥3 consecutive ventricular beats, QRS >120 ms, rate usually 120–250 bpm. Types include monomorphic VT, polymorphic VT, torsades (PMVT with long QT), ventricular…
Prominent Upright T Wave in V1
Key Points: Normal T Wave in V1: The normal ECG typically shows a flat or inverted T wave in lead V1 in sinus rhythm. An upright T wave in V1 can…
Premature Atrial Complexes (PACs)
Key Points PACs are early atrial depolarizations from an ectopic focus that create a premature P wave with a different morphology and axis than the sinus P wave, usually followed…
Atrial Fibrillation (AFib)
Key Points Prevalence: The most common sustained cardiac arrhythmia, particularly prevalent among elderly individuals, associated with increased stroke, heart failure, and mortality risks. Mechanism: Caused by chaotic, multiple reentry circuits…
Post-Cardiac Arrest ECGs
Key Points: Early post-ROSC ECGs often mislead. Obtain the first ECG immediately after ROSC, but treat it as an early snapshot, not the entire story. Post-arrest physiology, defibrillation, acidosis, and…
First-Degree AV Block
Key Points Defined by a PR interval >200 ms with consistent 1:1 AV conduction and no dropped QRS complexes. Conduction delay is most often at the AV node; His–Purkinje delay…
Premature Junctional Complexes (PJCs)
Key Points PJCs are premature impulses from ectopic foci in or near the AV junction. ECG hallmark is a narrow premature beat with an absent or retrograde P wave. Retrograde…
J Point: Basics
Key Points The J point is the junction where QRS ends and the ST segment begins. It is a location, not a waveform. ST deviation is judged at the J…
Blocked Premature Atrial Complexes (PACs)
Key Points Definition: early ectopic atrial beats that do not conduct to the ventricles. You see a premature P wave with no following QRS and a pause that is usually…
Free Content
Jump on our email list for free tips and insights delivered to your inbox monthly. No spam - just quick pearls and ECG education.
Categories
- No categories
© 2026 ECG Weekly. All rights reserved. | Terms of Use | Privacy Policy
Powered by the member(dev) platform
Loading...