ST elevation
V2, V3 · Men 40 and over
0.20 mV
≥ 2.0 mm
V2, V3 · Men under 40
0.25 mV
≥ 2.5 mm
V2, V3 · Women, any age
0.15 mV
≥ 1.5 mm
V2, V3 · Sex unknown
0.15 mV, an EKGLab default, not an AHA value
≥ 1.5 mm
All other leads
any patient · 0.10 mV
≥ 1.0 mm
ST depression
All leads
any patient, no stratification · −0.10 mV
≤ −1.0 mm
Reciprocal ST depression
Inferior STEMI · II, III, aVF
Opposite vector: depression of 1.0 mm or more in the mirror leads confirms the infarct direction
aVL, ± I
verifiedReciprocal changes are highlighted after reveal only when the Marquette 12SL measurement meets the depression threshold (≤ −0.10 mV) in that lead: anatomy predicts them, measurement confirms them.
infoThe "sex unknown" row is not an AHA criterion. The guidelines stratify V2 and V3 by sex and age but do not define a value for when those are unknown, because a clinician has the patient in front of them. Where the PTB-XL record is missing that information, EKGLab applies the lowest of the three published cut-points so a genuine elevation is shown rather than hidden.
infoGround 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.
infoThese same thresholds are used everywhere in EKGLab: the ST Map overlay on the 12-lead viewer, the per-lead ST badges, and the Beat Isolator’s ST flags all read one shared definition, so a lead judged elevated here is judged elevated there.
Pathological Q wave
V2, V3
Any Q wave wider than 20 ms (0.02 s), or a QS complex in V2 and V3
> 20 ms
I, II, aVL, aVF, V4, V5, V6
Q wave 30 ms (0.03 s) or wider and 1.0 mm (0.1 mV) or deeper, or a QS complex, in any two leads of a contiguous grouping
≥ 30 ms · ≥ 1 mm
Contiguous groupings
I with aVL · II, III, aVF · V1 through V6, neighbouring leads
two leads
What does not count
A Q in one lead only
III alone, aVL alone, a lone V5: no contiguous partner. Shown after reveal as "isolated" with zero weight; selecting it is an over-call
isolated
QS in V1 alone, or in V1 and V2 only
A normal variant. V1 counts only when V2 also qualifies, and a V2 QS needs V3
normal
Small septal q in I, aVL, V5, V6
Under 30 ms or under 1 mm: normal septal depolarisation
normal
aVR
Never evaluated
skipped
Tall R in V1 to V2
R 40 ms or wider with R/S ≥ 1 and an upright T: the inferobasal (posterior) Q-wave equivalent. A tall R, not a Q, and not part of this quiz
not scored
verifiedGround truth is the Marquette 12SL per-lead Q duration and depth from PTB-XL+, tested lead by lead against the criteria above. Every record in the bank also carries a cardiologist infarction statement of a matching wall (likelihood 50 or more) or a Q-wave statement, and records with LBBB, IVCD, pre-excitation or a paced rhythm are excluded because the criteria do not apply to them.
infoTwo EKGLab floors that are not in the definition. A V2 or V3 Q wave must be at least 0.5 mm deep to count, so the wave is actually visible at standard gain, and a QS complex must be at least 1 mm deep. Neither changes what the definition calls pathological; they keep the answer key to waves a reader can see.
infoThe clinical panel after reveal lists every lead’s Q duration and depth, and the record’s own cardiologist interpretation, so each answer can be checked against the numbers.