De Winter T waves is a specific electrocardiographic (ECG) pattern recognised as an ECG equivalent of ST-segment elevation myocardial infarction (STEMI), specifically indicating occlusion of the proximal left anterior descending (LAD) coronary artery 1. It is characterised by tall, symmetric, deeply inverted T waves in the precordial leads (V1-V6), often accompanied by ST-segment depression in these same leads 1. The recognition of this pattern is crucial as it signifies a high-risk situation requiring immediate intervention to restore coronary blood flow and limit myocardial damage 1. Failure to recognise this pattern can lead to delayed reperfusion and worse outcomes.
Epidemiology
The incidence of De Winter T waves is relatively low compared to classic STEMI presentations. It is more commonly observed in patients with anterior myocardial infarction, particularly those with proximal LAD occlusion. While specific prevalence data is limited, it is considered an important pattern to recognise in the context of acute coronary syndromes (ACS) 1. It can occur in both younger and older patients, and while some studies suggest a slightly higher prevalence in men, it can occur in both sexes. Risk factors are those associated with coronary artery disease, such as hypertension, hyperlipidaemia, diabetes mellitus, smoking, and family history.
Aetiology
primary causes / triggers: The primary cause is acute occlusion of the proximal left anterior descending (LAD) coronary artery 1. This occlusion leads to severe ischaemia of the anterior wall of the left ventricle, which manifests as the characteristic ECG changes.
secondary associations: While the direct cause is LAD occlusion, underlying conditions contributing to coronary artery disease, such as atherosclerosis, coronary artery spasm, or coronary embolism, are the usual predisposing factors. Hyperkalaemia can sometimes mimic this pattern, highlighting the importance of checking potassium levels 4.
Pathophysiology
The pathophysiology involves severe ischaemia of the anterior myocardial wall supplied by the proximal LAD artery 1. The exact mechanism leading to T wave inversion rather than ST elevation is not fully elucidated but is thought to relate to the specific location and extent of the ischaemia, potentially involving subendocardial ischaemia or early transmural ischaemia in the proximal LAD territory. The deep, symmetric T wave inversion reflects the widespread and severe myocardial cell dysfunction due to lack of oxygen and nutrients 1. This pattern is considered a STEMI equivalent because it indicates complete or near-complete occlusion requiring urgent reperfusion.
Clinical presentation
presenting symptoms: Patients typically present with symptoms of acute myocardial infarction, such as chest pain (often described as crushing or pressure-like), shortness of breath, nausea, vomiting, diaphoresis (sweating), and sometimes syncope or cardiac arrest 1. The onset is usually acute.
physical examination signs: Physical examination findings may include signs of sympathetic activation (tachycardia, hypertension, diaphoresis) or signs of cardiac decompensation (hypotension, pulmonary oedema, basal crackles, jugular venous distension) depending on the severity of the infarction and left ventricular dysfunction 1. An S4 gallop may be present.
Investigations
Bedside & Laboratory
specific test name: The key investigation is a 12-lead ECG, which should be performed immediately upon presentation with suspected ACS 1. The characteristic findings are deep, symmetric T wave inversions in leads V1-V6, often with ST-segment depression. Serial ECGs may be needed as the pattern can evolve. Blood tests, including cardiac troponins (high-sensitivity troponin I or T), CK-MB, and a full blood count, urea and electrolytes (including potassium) should be obtained urgently 1.
Imaging & Special Investigations
specific modality / diagnostic study: Echocardiography (transthoracic echocardiogram, TTE) is useful to assess left ventricular function, wall motion abnormalities (typically showing hypokinesis or akinesis of the anterior wall and septum), and to rule out other causes of chest pain or complications like pericardial effusion 1. Coronary angiography is the definitive diagnostic test to confirm the proximal LAD occlusion and guide revascularisation.
Management
acute / first-line management: Immediate management follows standard UK guidelines for STEMI equivalent presentations 1. This includes immediate transfer to a cardiac catheterisation laboratory for primary percutaneous coronary intervention (PCI) within the target time frame (typically within 90 minutes of first medical contact if presenting to a PCI-capable centre, or within 120 minutes if requiring transfer). Aspirin (300 mg loading dose), dual antiplatelet therapy (e.g., clopidogrel, prasugrel, or ticagrelor), anticoagulation (e.g., heparin or bivalirudin), oxygen (if hypoxic), nitrates (if no hypotension or RV infarct), and morphine (for pain relief) are administered according to local protocols 1. Beta-blockers and ACE inhibitors should be started as appropriate once haemodynamically stable.
definitive / long-term management: Definitive management involves successful revascularisation of the occluded LAD artery via PCI with stenting, or potentially coronary artery bypass grafting (CABG) in selected cases. Long-term management includes secondary prevention strategies such as antiplatelet therapy, statins, beta-blockers, ACE inhibitors/ARBs, lifestyle modifications (smoking cessation, diet, exercise), and cardiac rehabilitation 1.
Differential diagnosis
Hyperkalaemia: Can cause peaked T waves, which may sometimes resemble De Winter T waves, although typically less symmetric and often associated with other ECG changes like prolonged PR interval or widened QRS complex. Checking serum potassium is essential.
Left Ventricular Hypertrophy (LVH): Can cause T wave inversion in lateral leads (I, aVL, V5, V6), but typically not the deep, symmetric inversions seen in V1-V6 characteristic of De Winter T waves.
Takotsubo Cardiomyopathy: Can present with ECG changes mimicking ACS, including ST elevation or T wave inversion, but typically occurs in the context of significant emotional or physical stress and often shows characteristic apical ballooning on echocardiography or ventriculography.
Prognosis & complications
De Winter T waves indicate a complete or near-complete occlusion of a major coronary artery (proximal LAD), which carries a high risk of significant myocardial damage and adverse outcomes if not treated promptly 1. Prognosis depends heavily on the timeliness of reperfusion. Complications include heart failure, cardiogenic shock, ventricular arrhythmias, and death. Early and effective reperfusion significantly improves prognosis.