Usefulness of the four-variable formula on serial electrocardiograms in detecting subtle anterior myocardial infarction

Ekrem Taha Sert; Murat Gül; Kamil Kokulu; Hüseyin Mutlu

doi:10.1016/j.ajem.2023.08.032

Usefulness of the four-variable formula on serial electrocardiograms in detecting subtle anterior myocardial infarction

Am J Emerg Med. 2023 Nov:73:83-87. doi: 10.1016/j.ajem.2023.08.032. Epub 2023 Aug 21.

Authors

Ekrem Taha Sert¹, Murat Gül², Kamil Kokulu³, Hüseyin Mutlu³

Affiliations

¹ Department of Emergency Medicine, Aksaray University Medical School, Aksaray, Turkey. Electronic address: tahaekrem@hotmail.com.
² Department of Cardiology, Aksaray University Medical School, Aksaray, Turkey.
³ Department of Emergency Medicine, Aksaray University Medical School, Aksaray, Turkey.

PMID: 37633077
DOI: 10.1016/j.ajem.2023.08.032

Abstract

Objective: To perform serial electrocardiogram (ECG) analyses in patients with subtle ECG changes in the anterior leads and evaluate the performance of the four-variable formula in detecting left anterior descending (LAD) coronary artery occlusion.

Methods: This prospective study included patients admitted to the emergency department with acute chest pain between April 2021 and January 2023, whose initial ECG was not diagnostic but indicated suspicion of myocardial infarction (MI) and who underwent percutaneous coronary intervention in their follow-up. The control group consisted of patients who were diagnosed with benign variant ST-segment elevation (BV-STE) due to ST-segment elevation (STE) of at least 1 mm in the anterior lead, who had normal cardiac troponin levels, and who presented with non-cardiac chest pain. Following admission, six ECGs were taken at 10-min intervals. The scores of all patients were calculated with the four-variable formula on serial ECGs and compared between the groups.

Results: A total of 232 patients, including 116 with anterior MI and 116 with BV-STE, were included in the study. When the cut-off value for the four-variable formula was taken as ≥18.2, the sensitivity, specificity, and diagnostic accuracy of the first ECG were determined to be 82.7%, 85.3%, and 83.6%, respectively. We found that the four-variable formula had the highest sensitivity, specificity, and diagnostic accuracy in detecting LAD occlusion for the ECG taken at the 20th minute (83.6%, 89.6%, and 86.2%, respectively).

Conclusion: The four-variable formula was found to be a valid method for the differentiation of STEMI and BV-STE in patients with subtle ECG changes. While managing this patient group, using serial ECGs rather than a single ECG to evaluate the clinical status of patients can help clinicians make more accurate decisions.

Keywords: Benign variant ST-segment elevation; Four-variable formula; Serial electrocardiograms; Subtle anterior myocardial infarction.