Choose a Quiz
Practice rhythm strips and full 12-lead interpretation.
Assigned to you
Quizzes your instructor has assigned to your class.
Rhythm Identification
Read the strip: rate, regularity, and morphology on a single lead.
Practice Quiz
6 curated ECG strips: NSR, AFIB, AFL, PVC, LBBB, RBBB. Great for getting started.
12-Lead Interpretation
Localize findings across all twelve leads on a real ECG.
ST Elevation
Identify which leads show ST elevation on a real 12-lead ECG. Covers inferior, anterior, and lateral STEMI patterns.
ST Depression
Identify leads showing ST depression on a real 12-lead ECG. Includes subendocardial ischemia and reciprocal patterns.
Bundle Branch Blocks
Identify LBBB, RBBB, or neither on real 12-lead ECGs. Confirmed complete blocks and clean narrow-complex records, drawn from the PTB-XL database.
Rhythm
Identification
Stuck on this rhythm?
Describe what you see, the rate, regularity, P waves, QRS width, and I'll guide you toward the right interpretation without giving the answer.
Quiz Complete!
Keep practicing to master rhythm interpretation.
Lead Accuracy Map
Where you found, missed & over-called ST elevation
Left BBB, Right BBB, or Neither?
AHA/ACC/HRS ST Thresholds
AHA/ACCF/HRS 2009 ECG Standards, Part VI: Acute Ischemia/Infarction
Wagner GS et al., Circulation 2009;119:e262–e270 (PMID 19281933)
ST Elevation
| Lead(s) | Patient | Threshold |
|---|---|---|
| V2, V3 | Men ≥ 40 yr | ≥ 2.0 mm (0.20 mV) |
| V2, V3 | Men < 40 yr | ≥ 2.5 mm (0.25 mV) |
| V2, V3 | Women (any age) | ≥ 1.5 mm (0.15 mV) |
| V2, V3 | Sex unknown | ≥ 1.5 mm (conservative) |
| All other leads | Any | ≥ 1.0 mm (0.10 mV) |
ST Depression
| Lead(s) | Patient | Threshold |
|---|---|---|
| All leads | Any | ≤ −1.0 mm (−0.10 mV) |
Reciprocal ST Depression (Inferior STEMI)
| Elevation territory | Reciprocal lead(s) | Mechanism |
|---|---|---|
| Inferior (II, III, aVF) | aVL, ± I | Opposite vector; STD ≤ −1.0 mm confirms infarct direction |
Reciprocal changes are highlighted after reveal only when the Marquette 12SL measurement meets the STD threshold (≤ −0.10 mV) in that lead, anatomy predicts them, measurement confirms them.
Ground truth is the Marquette 12SL numeric ST measurement from PTB-XL+, filtered through the sex/age-adapted threshold for this patient. A lead is marked "correct" only when its measured ST meets the applicable threshold.