ISSN: 1885-5857 Impact factor 2023 7.2
Vol. 77. Num. 3.
Pages 277 (March 2024)

Letter to the editor
Looking for ECG signs of acute coronary syndrome

En búsqueda de signos ECG para el síndrome coronario agudo

Miquel Fiol SalaaAndrés Carrillo LópezbAlberto Rodríguez Salgadoc
Rev Esp Cardiol. 2023;76:66510.1016/j.rec.2022.12.014
José Antonio Fernández-Sánchez, Antonio Esteban Arriaga-Jiménez, Miriam Jiménez-Fernández
Rev Esp Cardiol. 2024;77:277-810.1016/j.rec.2023.10.008
José Antonio Fernández-Sánchez, Antonio Esteban Arriaga-Jiménez, Miriam Jiménez-Fernández

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To the Editor,

We read with interest the article published by Fernández-Sánchez et al.1 in which they described the South African flag sign. This is one of many signs already described to help identify particular electrocardiogram patterns associated with acute coronary syndrome, such as the shark fin sign, the triangular wave, and the lambda-like wave. Nonetheless, in our opinion, the South African flag sign is an ill-suited teaching tool,2 as one must first be familiar with the flag. The sign also demands a certain degree of imagination and only applies to 3×4 display formats. In addition, the ST depression mirror image is also observed in II and aVF, meaning it is positioned outside the flag. This is, however, not the main point we wish to make in reference to the article by Fernández-Sánchez et al.

The pattern described by the authors is a characteristic finding in first diagonal or intermediate branch occlusion. Although this pattern has traditionally been considered to depict high lateral ischemia due to circumflex artery occlusion, when not associated with ST depression in V1-V2,3 it is a manifestation of occlusion of the first diagonal or intermediate branch, which both supply blood to the mid-low anterolateral wall, not the high lateral wall.4 Strictly speaking, thus, the pattern represents mid-anterior myocardial infarction, which in its subacute or chronic phase can be confirmed by delayed enhancement cardiac magnetic resonance imaging.5

We agree with the authors that it is a grave error to expect ST elevation in 2 contiguous leads when assessing a potential case of acute coronary syndrome. In this particular case, however, the I and aVL leads displaying ST elevation in the frontal plane can be considered contiguous.

FUNDING

Article funded by Fundación Instituto de Investigación Sanitaria de les Illes Balears (IdISBa).

STATEMENT ON THE USE OF ARTIFICIAL INTELLIGENCE

Artificial intelligence has not been used.

AUTHORS’ CONTRIBUTIONS

All the authors contributed to revising this letter to the editor.

CONFLICTS OF INTEREST

No conflicts of interest.

References
[1]
J.A. Fernández-Sánchez, A.E. Arriaga-Jiménez, M. Jiménez-Fernández.
IAMCEST lateral alto con signo de la bandera de Sudáfrica.
Rev Esp Cardiol., (2023), 76 pp. 665
[2]
Laszlo Littmann.
South African flag sign: a teaching tool for easier ECG recognition of high lateral infarct.
Am J Emerg Med., (2016), 34 pp. 107-109
[3]
Y. Birnbaum, D. Hasdai, S. Sclarovsky, I. Herz, B. Strasberg, E. Rechavia.
Acute myocardial infarction entailing ST segment elevation in lead AVL: electrocardiographic differentiation among occlusion of the left anterior descending, first diagonal and first obtuse marginal coronary arteries.
Am Heart J., (1996), 131 pp. 38-42
[4]
A. Bayés de Luna, G. Wagner, Y. Birnbaum, et al.
A new terminology for the left ventricular walls and for the location of myocardial infarcts that present Q wave based on the standard of cardiac magnetic resonance imaging: a statement for healthcare professionals from a committee appointed by the International Society for Holter and Non Invasive Electrocardiography.
Circulation., (2006), 114 pp. 1755-1760
[5]
A. Bayes de Luna, J.M. Cino, S. Pujadas, et al.
Concordance of electrocardiographic patterns and healed myocardial infarction location detected by cardiovascular magnetic resonance.
Am J Cardiol., (2006), 97 pp. 443-451
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