Jimena Rodríguez-Carbó, Ana Mincholé, Esther Pueyo
Abstract
Ischemic heart disease remains the leading cause of mortality worldwide. Its diagnosis largely relies on detecting dynamic changes in the ST segment of the electrocardiogram (ECG). However, alterations in other ECG waves and intervals have also been reported. One factor that is often overlooked is the presence of a prior myocardial infarction and its influence on the myocardial response to a new ischemic event. This study aimed to quantify the magnitude and temporal dynamics of ECG changes during acute myocardial ischemia and to evaluate how a previous infarction modifies these changes.
Introduction
Cardiovascular diseases (CVD) remain the leading cause of mortality worldwide for both men and women [1]. Among all CVD, ischemic heart disease accounts for the highest number of deaths, with mortality nearly threefold higher than that attributed to the second most common cause, ischemic stroke [2].
Myocardial ischemia constitutes the underlying pathophysiological mechanism of ischemic heart disease and is characterized by a reduction in blood supply to the myocardium as a result of the partial or complete obstruction of one or more coronary arteries.
Materials and methods
Study population
This study was conducted using the STAFF III database [16], which comprises ECG recordings of 102 patients undergoing elective PCI. This database is available at https://physionet.org/content/staffiii/1.0.0/. The patients had a mean age of 60.7 ± 11.52 years, and the interventions targeted one of the major coronary arteries: the left circumflex artery (LCx), the right coronary artery (RCA), or the left anterior descending artery (LAD).
The occlusion distribution included 21 LCx, 47 RCA, and 34 LAD cases. Although some patients presented with multiple occlusions, only the first balloon inflation of the complete PCI procedure was analyzed.
Results
Temporal dynamics and magnitude of ischemia-induced ECG changes
Table 1 shows the baseline characteristics table that summarizes the study population; it shows the percentage of patients and the median values with the interquartile range. Extent and severity percentages were significantly different between the occluded arteries groups, with LAD occlusion patients having higher values, followed by RCA and the smallest values for LCx occlusion patients.
Discussion
The study demonstrated that myocardial ischemia induces rapid and marked alterations in multiple ECG markers extending beyond the ST segment. These changes exhibit a clear temporal pattern, with repolarization-related markers showing earlier and larger responses than depolarization-related markers. Importantly, the magnitude and time course of these electrical alterations were not uniform but were significantly modulated by the underlying myocardial substrate, including sex, age, prior myocardial infarction, and occlusion location.
Conclusions
By comparing ECG recordings obtained before and during PCI-induced ischemia, we show that acute myocardial ischemia produces significant alterations not only in ST-segment deviation but also in multiple ECG markers reflecting ventricular depolarization and repolarization. The magnitude and temporal dynamics of these changes vary according to the occlusion site, patient sex, and the presence of a prior MI.
Acknowledgments
Computations were performed using ICTS NANBIOSIS (HPC Unit at U. Zaragoza).
Citation: Rodríguez-Carbó J, Mincholé A, Pueyo E (2026) Characterizing acute ischemia via ECG: A study of severity, extent, and spatial variability in myocardial infarction and non-infarction groups. PLoS One 21(10): e0361220. https://doi.org/10.1371/journal.pone.0361220
Editor: Redoy Ranjan, Bangabandhu Sheikh Mujib Medical University, BANGLADESH
Received: February 20, 2026; Accepted: October 7, 2026; Published: October 29, 2026
Copyright: © 2026 Rodríguez-Carbó et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Data Availability: The data underlying the results presented in the study is available in PhysioNet (https://physionet.org/content/staffiii/1.0.0/).
Funding: This work was supported by the Agencia Estatal de Investigación - Ministerio de Ciencia e Innovación (Spain) in the form of projects PID2022-140556OB-I00 and PID2023-148975OB-I00 funded by MCIN/AEI/10.13039/501100011033/ERDF, EU awarded to EP and AM, CNS2022-135899 funded by MCIN/AEI/10.13039/501100011033/ERDF, EU and the EU “NextGenerationEU”/PRTR awarded to AM, and project TED2021-130459B-I00 funded by MCIN/AEI/10.13039/501100011033 and the EU “NextGenerationEU”/PRTR and ‘ERDF A way of making Europe’ awarded to AM, EP, and JRC. The study was also supported by fellowship RYC2019-027420-I/AEI/10.13039/501100011033 funded by the Ramón y Cajal Program awarded to AM given by the Agencia Estatal de Investigación - Ministerio de Ciencia e Innovación (Spain), by the project BSICoS group T39_23R funded by the Aragón Government and ‘ERDF 2014-2020 Building Europe from Aragon’ awarded to AM, EP, and JRC, and by the PhD fellowship ‘Ayudas para iberoamericanos y ecuatoguineanos en Estudios de Doctorado - Curso 2023/2024’ funded by the University of Zaragoza and Banco Santander awarded to JRC. There was no additional external funding received for this study. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interests: The authors have declared that no competing interests exist.
