ECG patterns of ischaemia and infarction — structured written assessment

Abbreviations

Short-answer question 1 (10 marks)

Scenario

Practice scenario (not a real patient). A 58-year-old man has 1 hour of ongoing central chest pain. His ECG shows new ST elevation of 2 mm at the J-point in II, III and aVF, ST depression of 1 mm in I and aVL, and 1 mm ST depression in V1–V3 with positive terminal T waves. There is no LVH or bundle branch block. The emergency physician has diagnosed an inferior STEMI.

Questions — question 1

1. State the ST elevation cut-points of ESC 2023 and say whether his ECG meets them. (2)^[1]
2. What does the Fifth UDMI (2026) say about reciprocal ST depression, and how does it help separate coronary occlusion from pericarditis or early repolarisation? (2)^[12]
3. Which additional leads should be recorded, why, and with what ESC 2023 class? (3)^[1]
4. What might the ST depression in V1–V3 represent, and what do the posterior leads add? (3)^[1][12]

Model answers — question 1

1. ESC 2023, in the appropriate clinical context: new ST elevation at the J-point in at least two contiguous leads of ≥2.5 mm in men under 40, ≥2 mm in men 40 or over, or ≥1.5 mm in women regardless of age in V2–V3, and/or ≥1 mm in the other leads, in the absence of LV hypertrophy or LBBB, is considered suggestive of ongoing acute coronary occlusion.^[1] He has 2 mm in II, III and aVF, which meets the ≥1 mm cut-point for leads other than V2–V3.^[1]
2. The Fifth UDMI (2026) says that with an acute coronary pathology, ST elevation is typically regional and often accompanied by reciprocal ST depression.^[12] It adds that regional ST elevation generally reflects an acute coronary occlusion requiring immediate restoration of blood flow to reduce infarct size.^[12] In contrast, in other conditions such as pericarditis or early repolarisation, ST elevation is often diffuse or global, not confined to a single coronary territory, and occurs without reciprocal changes.^[12]
3. Right precordial leads V3R and V4R: ESC 2023 recommends them in suspected inferior STEMI to assess for ST elevation, and ST elevation in V3R and V4R is highly suggestive of ongoing RV ischaemia.^[1] The Fifth UDMI (2026) says a right ventricular MI is indicated by ST elevation in the right precordial leads (V3R–V6R), especially when accompanied by ST elevation in aVR.^[12] Posterior leads V7–V9: ESC 2023 says ST depression in V1–V3, especially when the terminal T wave is positive, is highly suggestive of posterior coronary occlusion, often of the left circumflex artery.^[1] ESC 2023 Recommendation Table 1: additional ECG leads (V3R, V4R and V7–V9) are recommended in inferior STEMI or if total vessel occlusion is suspected and standard leads are inconclusive (Class I, Level B).^[1]
4. ESC 2023: ST depression in V1–V3, especially with a positive terminal T wave, and/or ST elevation in V7–V9 is highly suggestive of posterior coronary occlusion, often of the left circumflex artery.^[1] The Fifth UDMI (2026) says a posterior MI is suggested by ST depression ≥1 mm in V1, V2 and/or V3, particularly when the R-wave amplitude is greater than the S wave (dominant) in V1 or V2, and is confirmed by ST elevation in the posterior leads V7 to V9.^[12] ACC/AHA 2025 Table 3: posterior leads (V7–V9) should be obtained in patients with suspected left circumflex occlusion, particularly in the setting of isolated ST depression ≥0.5 mm in V1–V3.^[2]

Short-answer question 2 (10 marks)

Scenario

Practice scenario (not a real patient). A 46-year-old woman had 90 minutes of chest pain at rest last night and is now pain free. Her ECG shows an isoelectric J-point with biphasic T waves in V2 and V3. Her first high-sensitivity troponin is pending.

Questions — question 2

1. Name the pattern, state what ESC 2023 links it to, and state how the Fifth UDMI (2026) describes Wellens syndrome. (3)^[1][12]
2. Where does NHFA/CSANZ 2025 place this pattern, and what does it recommend when it is recognised? (3)^[4]
3. The Fifth UDMI (2026) cites a 1982 report for Wellens syndrome. Summarise that report. (2)^[12][8]
4. NHFA/CSANZ 2025 gives two other high-risk ECG patterns as examples alongside it. Name them, and what ESC 2023 or the Fifth UDMI (2026) says about each. (2)^[4][1][12]

Model answers — question 2

1. Wellens T waves: ESC 2023 lists biphasic T waves or prominent negative T waves (Wellens sign, related to severe proximal LAD stenosis) among the ECG abnormalities of NSTE-ACS.^[1] The Fifth UDMI (2026) Table 5 describes Wellens syndrome as biphasic or deeply inverted T waves in leads V2 and V3.^[12] Its text lists Wellens syndrome (biphasic or deeply inverted T waves in V2–V3 during pain-free intervals) among further ECG patterns that suggest acute coronary occlusion.^[12]
2. NHFA/CSANZ 2025 lists Wellens T waves among high-risk ECG patterns associated with potential progression to ACOMI, separately from the ACOMI patterns it names beyond the traditional criteria (including high lateral MI, posterior MI, right ventricular MI, De Winter T waves, modified Sgarbossa criteria and transient STE).^[4] Recognition should prompt urgent, continuous cardiac monitoring and consideration for coronary angiography.^[4]
3. The Fifth UDMI (2026) cites de Zwaan, Bär and Wellens (Am Heart J 1982) for Wellens syndrome.^[12] Of 145 patients consecutively admitted with unstable angina, 26 (18%) showed the characteristic precordial ST-T pattern, which the authors linked to a critical stenosis high in the LAD.^[8] Despite symptom control with nitroglycerin and beta blockade, 12 of 16 patients (75%) not operated on developed a usually extensive anterior wall infarction within a few weeks of admission.^[8]
4. Diffuse ST depression in multiple leads with ST elevation in aVR: ESC 2023 says ST depression ≥1 mm in ≥6 surface leads, with ST elevation in aVR and/or V1, suggests multivessel ischaemia or left main obstruction, particularly with haemodynamic compromise.^[4][1] The Fifth UDMI (2026) says global ischaemic changes (diffuse ST depression along with ST elevation in aVR) may reflect left main stem or balanced three-vessel coronary artery disease, and that these ECG findings are not specific to MI and can be observed in other cardiac and non-cardiac conditions.^[12] Hyperacute T waves: the Fifth UDMI Table 5 describes them as symmetrical, broad T waves disproportionately large to the preceding QRS complex in two contiguous leads.^[4][12] Its text lists marked ST depression or hyperacute T waves in V1–V2 with reciprocal changes elsewhere among further ECG patterns that suggest acute coronary occlusion.^[12]