What are De Winter T-waves and when should you activate the cath lab?

De Winter T-waves: J-point depression + tall symmetric upright T waves in V1–V6 in a patient with chest pain. They represent proximal LAD occlusion without classic ST elevation. Cath lab activation is indicated immediately — same urgency as overt STEMI. De Winter T-waves are one of the most commonly missed high-risk ECG patterns in emergency triage.

What does Wellens syndrome look like on ECG?

Wellens syndrome: biphasic T waves (Type A) or deep symmetric T-wave inversions (Type B) in V2–V3, occurring in a patient who is pain-FREE but recently had ischemic symptoms. This 'reperfusion pattern' indicates a critically narrow proximal LAD that temporarily reperfused. Stress testing is absolutely contraindicated — exercise can trigger re-occlusion. Urgent cardiology referral is required.

ECG Mastery · Clinical Guide

STEMI equivalents: De Winter T-waves, Wellens syndrome, and other missed occlusion patterns

STEMI equivalents for nurses: De Winter T-waves, Wellens syndrome, posterior STEMI, LBBB with Sgarbossa criteria — patterns requiring emergent cath lab activation without classic ST elevation.

Why STEMI equivalents matter: same urgency, different appearance

Traditional STEMI criteria require ST elevation ≥1mm in two contiguous limb leads or ≥2mm in precordial leads. But acute coronary occlusion — which requires emergent reperfusion — can present without meeting these criteria. STEMI equivalents are patterns indicating total or near-total coronary occlusion without classic ST elevation.

De Winter T-waves: J-point depression (1–3mm) with tall, symmetric, upright T waves in V1–V6. Caused by proximal LAD occlusion. No ST elevation is present — commonly misdiagnosed as early repolarization or hyperkalemia. These patients need cath lab activation now, not troponin-guided workup.

Wellens syndrome (reperfusion T-wave pattern): biphasic T waves (Type A) or deep symmetric T-wave inversions (Type B) in V2–V3 in a pain-free patient. Represents reperfused proximal LAD stenosis — the plaque has momentarily reperfused but remains critically narrow. These patients are at extremely high risk for sudden re-occlusion. Stress testing is contraindicated — they need urgent cardiology consultation and likely PCI.

Frequently asked questions

What are De Winter T-waves and when should you activate the cath lab?: De Winter T-waves: J-point depression + tall symmetric upright T waves in V1–V6 in a patient with chest pain. They represent proximal LAD occlusion without classic ST elevation. Cath lab activation is indicated immediately — same urgency as overt STEMI. De Winter T-waves are one of the most commonly missed high-risk ECG patterns in emergency triage.
What does Wellens syndrome look like on ECG?: Wellens syndrome: biphasic T waves (Type A) or deep symmetric T-wave inversions (Type B) in V2–V3, occurring in a patient who is pain-FREE but recently had ischemic symptoms. This 'reperfusion pattern' indicates a critically narrow proximal LAD that temporarily reperfused. Stress testing is absolutely contraindicated — exercise can trigger re-occlusion. Urgent cardiology referral is required.

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