ST-segment elevation myocardial infarction, stenting of the infarct-related coronary artery, silent (painless) myocardial ischemia, diabetes mellitus, 24-hour electrocardiographic monitoring.
 Introduction. Currently, approximately 422 million people in the world have diabetes mellitus, and over 1.3 million individuals in Ukraine are diagnosed with diabetes mellitus. Diabetic neuropathy is known to contribute to the development of atypical and painless variants of ischemic heart disease in individuals with diabetes. This poses a challenge for timely diagnosis and obscures the course of ischemic heart disease, as the prevalence of silent myocardial ischemia is significantly high in these patients. Therefore, the aim of this study is to investigate the occurrence of myocardial ischemia episodes in patients with ST-elevation myocardial infarction within the first day following stenting of the infarct-related coronary artery. Furthermore, we aimed to demonstrate the painless nature of these episodes in the presence of type 2 diabetes mellitus through a clinical case presentation.
 Materials and methods. 30 patients with ST-segment elevation myocardial infarction were examined, and 24-hour electrocardiographic monitoring was performed during the first day after the infarct-related coronary artery stenting. Results. Episodes of transient myocardial ischemia were registered in 50% of people. We found that the majority of episodes (80%) were painless. In the presence of diabetes mellitus, only episodes of painless myocardial ischemia were noted that is supported by the example of a clinical case. The study highlighted the informativeness of 24-hour electrocardiographic monitoring in identifying episodes of myocardial ischemia, particularly in its painless variant. The results demonstrate that patients with ST-elevation myocardial infarction (STEMI) experience episodes of transient myocardial ischemia within the first day after coronary artery stenting, with a majority of these episodes being painless. Furthermore, in the presence of diabetes mellitus, ischemic episodes tend to be painless. Therefore, 24-hour electrocardiographic monitoring serves as a valuable method for the detection of myocardial ischemia.