5.2

Minnesota Code 5-2: moderate T-wave inversion 1–5 mm — causes, normal variants and when it needs evaluation.

Code 5.2 — Minnesota Code 5-2: moderate T-wave inversion. The T wave is negative, or biphasic with a negative first part, and its negative amplitude is 1.0 mm or more but less than 5.0 mm in a lead where it should normally be upright. Together with code 5-1, it belongs to the major T-wave abnormalities. It is often found in myocardial ischaemia, after an infarction, in left ventricular hypertrophy and in other heart diseases.

Minnesota Code 5T-wave inversionRepolarisation

Negative T amplitude1.0 – < 5.0 mm

Leads assessedI, II, aVL, aVF, V2–V6

Classmajor abnormality

Novacodepart of NC-5.6

Figure 1. Left: normal upright T wave. Right: moderate T-wave inversion of about 3 mm (Minnesota 5-2).

Causes

Myocardial ischaemia or a past myocardial infarction
Left ventricular hypertrophy with strain (asymmetric inversion in leads with tall R waves)
Cardiomyopathy, myocarditis, pericarditis in a later phase
Right ventricular overload (pulmonary embolism, pulmonary hypertension) — mainly V1–V3
Medicines (digoxin, antiarrhythmics), electrolyte disorders
Normal variants: "persistent juvenile" T inversion in V1–V3 in young people, and T inversion in some athletes of African or Caribbean descent preceded by J-point elevation

Interpretation

Less concerning

Long-standing, unchanged inversion; obvious non-cardiac cause; isolated change in one lead; normal echocardiogram.

More concerning

New inversion compared with earlier ECGs; symmetric inversion in several neighbouring leads; symptoms; inversion in V4–V6 or inferior leads in a young athlete (exclude cardiomyopathy).

Clinical significance

On its own, moderate T inversion is not diagnostic, but it should not be ignored. In people with coronary risk factors it may indicate silent ischaemia. When it appears together with ST depression or Q waves, the likelihood of significant heart disease is higher. Large cohort studies have shown that such T-wave abnormalities predict cardiovascular events.

What to do

Discuss the result with a doctor. Comparison with previous ECGs, echocardiography and assessment of coronary risk factors are usually needed.

Call emergency services

if you have chest pain, breathlessness, fainting or palpitations.

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

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