What's new
Every change to ECG Sweep, newest first.
September 2026
- New
Hyperkalaemia and hypokalaemia on the 12-lead
Both potassium disorders as progressions you can step through. Hyperkalaemia from peaked T waves at K⁺ 6, through a long PR and a wide QRS, to the sine wave and ventricular fibrillation. Hypokalaemia from a flatter T and a small U at K⁺ 3.0, through ST depression and a U taller than the T, to torsades de pointes. Each form has its own short article, and tapping a lead shows its measurements beside the normal range.
- New
ECG flashcards
A deck of ECG flashcards: a strip and a question, four answers to choose from, then the card turns over to the findings, the look-alikes and a link to the live 12-lead. The first card is up; more are added every week.
- New
Left anterior and left posterior fascicular block on the 12-lead
Both fascicular blocks, drawn from the part of the left ventricle each one reaches late, each with an article and a With RBBB variant for bifascicular block. Each links to the axis page at its own angle.
- New
Incomplete right and left bundle branch block
Both bundle branch blocks now have an incomplete variant, chosen beside the title: the same pattern with a QRS of 110 to 119 ms, drawn from the same late activation, shorter. Each article explains how to tell it from the complete block.
- New
A Normal switch draws the normal ECG behind the whole 12-lead
Under the tracing, a Normal switch draws the same ECG without the condition in grey behind every lead. The grey hides under the trace wherever nothing changed, so in right bundle branch block it shows only the late QRS and the turned-over T waves. N turns it on and off, and the page remembers your choice.
- New
Right and left bundle branch block on the 12-lead
12-lead tracings of complete right and left bundle branch block, each drawn from the heart's own late activation, with an article on reading it. Right: the rSR′ in V1 and the broad S in I and V6. Left: the QS in V1, the broad notched R in I and V6, the discordant ST and T, and why the usual signs of infarction cannot be read.
- New
Articles for the five sinus rhythms
Normal sinus rhythm, sinus bradycardia, sinus tachycardia, sinus arrhythmia and sinus arrest each have an article: how to recognise it, why it happens and what it can be mistaken for.
- New
Every rhythm article has a strip to read yourself, and the same strip annotated
Each article now carries a 30 second strip drawn by the simulator to work through first, then the same strip marked up with every interval measured.
- New
The PAC family: PACs, blocked PACs and aberrant PACs
Three articles on premature atrial contractions, with bigeminy and trigeminy, and two simulation faults they exposed fixed along the way.
- New
A cardiac axis page with three ways to read the axis
Drag the axis around the dial and watch the six limb leads follow, then work it out by the quadrant, isoelectric or three-lead method.
- New
Articles for 17 rhythms
Each rhythm's page now explains how to recognise it, why it happens and what it can be mistaken for, beside the live trace.
- New
Wolff-Parkinson-White pattern
A short PR and a delta wave slurring the start of a wide QRS, the triad that defines the pattern.
- New
The SVT family: AVNRT, AVRT and focal atrial tachycardia
Three narrow-complex tachycardias, each drawn with the features that tell them apart.
- New
Comment on a rhythm, or request one
Every rhythm has a way to send a comment, and a request page takes suggestions for rhythms to add.