Home > ECG findings

5.1

Minnesota Code 5-1: deep T-wave inversion ≥ 5 mm — ischaemia, Wellens pattern, cardiomyopathy and other causes; when to seek urgent care.

Code 5.1 — Minnesota Code 5-1: deep T-wave inversion. The T wave is negative, or biphasic with a negative first part, and its negative amplitude is 5.0 mm (0.5 mV) or more in a lead where the T wave should normally be upright. This is the most pronounced T-wave abnormality in the Minnesota Code. It can indicate myocardial ischaemia, an evolving or past infarction, severe hypertrophy, cardiomyopathy or other serious conditions.

Minnesota Code 5T-wave inversionRepolarisation

Negative T amplitude≥ 5.0 mm

Leads assessedI, II, aVL, aVF, V2–V6

Classmajor abnormality

Novacodepart of NC-5.6

What the T wave shows

The T wave represents ventricular repolarisation, the electrical recovery of the muscle after each contraction. In adults it is normally upright in leads I, II and V3–V6 and negative in aVR. It may normally be negative in III, aVR and V1, so the Minnesota Code does not code T inversion in these leads. In aVL and aVF it is coded only when the QRS there is mainly upright. Deep inversion in leads where the T should be positive means that repolarisation is markedly disturbed.

Figure 1. Left: normal upright T wave. Right: deep, symmetric T-wave inversion ≥ 5 mm (Minnesota 5-1) — typical of ischaemia or an evolving infarction.

Causes of deep T-wave inversion

Cause	Features
Acute coronary syndrome, evolving infarction	Symmetric deep T inversion in a coronary territory; with chest pain and rising troponin
Wellens pattern	Deep symmetric (or biphasic) T in V2–V3 after chest pain resolves; critical stenosis of the proximal left anterior descending artery
Apical hypertrophic cardiomyopathy	"Giant" negative T waves in V3–V5 with high R voltage
Takotsubo (stress) cardiomyopathy, myocarditis	Widespread deep T inversion with QT prolongation
Pulmonary embolism, right ventricular strain	T inversion in V1–V4 and III
Intracranial haemorrhage	Wide, deep "cerebral" T waves, long QT
LVH with strain, after pacing or tachycardia (memory T waves)	Asymmetric inversion, context-dependent

Clinical significance

Deep T-wave inversion in a person with chest pain needs urgent evaluation, even if the pain has gone. The Wellens pattern, for example, may precede a large anterior infarction. In people without symptoms, deep inversion is a reason for echocardiography and further cardiac testing, because it can be the first sign of cardiomyopathy. In population studies, major T-wave abnormalities are associated with higher cardiovascular mortality.

Call emergency services

if T-wave inversion is found together with current or recent chest pain, breathlessness, fainting, severe headache or neurological symptoms.

References

Prineas RJ, Crow RS, Zhang ZM. The Minnesota Code Manual of Electrocardiographic Findings. 2nd ed. London: Springer; 2010. doi:10.1007/978-1-84882-778-3
Rautaharju PM, Surawicz B, Gettes LS. AHA/ACCF/HRS recommendations for the standardization and interpretation of the electrocardiogram: part IV: the ST segment, T and U waves, and the QT interval. Circulation. 2009;119(10):e241–e250. doi:10.1161/CIRCULATIONAHA.108.191096
de Zwaan C, Bär FW, Wellens HJ. Characteristic electrocardiographic pattern indicating a critical stenosis high in left anterior descending coronary artery in patients admitted because of impending myocardial infarction. Am Heart J. 1982;103(4 Pt 2):730–736. doi:10.1016/0002-8703(82)90480-x

This article is for general information and does not replace a consultation with a doctor. ECG findings must be interpreted by a physician together with symptoms and other tests.

Published on 14 May 2019

Medical Book