5.7
Code 5.7 (Novacode NC-5.7) — minor Q waves. The ECG shows small Q waves that are slightly larger than normal septal q waves, but without significant ST-segment or T-wave changes. This is a minor finding: it may reflect a small old scar, but it is much more often caused by heart position, body build or normal variation. The Minnesota equivalent is code 1-3-x.
Common explanations
- Normal septal activation, especially in leads III, aVL and aVF
- Horizontal heart position, obesity, pregnancy
- Left ventricular hypertrophy, conduction disorders
- Small old myocardial infarction (less common)
Clinical significance
Minor Q waves on their own have a low predictive value for infarction. They become more meaningful when they are new compared with earlier ECGs, when they occur in several adjacent leads, or when the person has symptoms or coronary risk factors. In serial studies, Novacode was designed to distinguish such minor findings from clinically significant progression.
Usually no special action is needed beyond discussing the ECG with a doctor and keeping risk factors under control. Seek care if you have chest pain or breathlessness.
References
- Rautaharju PM, Park LP, Chaitman BR, Rautaharju F, Zhang ZM. The Novacode criteria for classification of ECG abnormalities and their clinically significant progression and regression. J Electrocardiol. 1998;31(3):157–187.
- 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
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