ST-segment elevation myocardial infarction and the clinical significance of differentiated electrocardiogram

Abstract

Aim. To evaluate the markers of changing dynamics recorded by digital processing of routine ECG using own diagnostic complex software “Smart-ECG” in patients with ST-segment elevation myocardial infarction (STEMI) based on the results of a 40-day follow-up. Materials and methods. The main group consisted of 20 patients with STEMI according to the ESC guidelines (2017) (mean age of males 56.11 ± 11.62, n = 10; mean age of females 58.22 ± 13.11, n = 10). ECG were analyzed using own developed diagnostic complex software “Smart-ECG” on the 1st, 10th, 40th day after STEMI. The first derivative of T wave – ratio of maximum velocity (MVR), inclination angle (β) and inclination height (H) of ST segment was calculated. The control group – 20 apparently healthy people. Results. MVR indicators decreased by 61.90 %, 68.20 % and 51.48 % on the 1st, 10th and 40th day, respectively, after STEMI as compared to those of the control group (p < 0.01). At the moment of the maximum ST segment elevation, the height (H) of ST inclination was 347.7 % increased (p < 0.01); on the 40th day, H was 25 % increased, close to control indicators, with ST segment shift to isoline (р > 0.05). During the acutest period, the angle β increased by 172.2 % (p < 0.01) and then decreased by 15.8 % at the recovery phase, but insignificantly. Conclusions. Self-developed medical software “Smart-ECG” for qualitative evaluation of ECG is an effective tool to diagnose pathological changes in the myocardium, makes it possible to improve the specificity, sensitivity and prognostic significance of ECG in STEMI. The significant decrease in MVR has been detected at all stages of STEMI, which was associated with a violation of electrogenesis in the repolarization phase; the critical increase in ST slope indicators (angle β and height H) on the 1st day has been found as a characteristic of ST elevation, as well as its decrease on the 40th day as a sign of reduced potential difference between healthy and damaged areas of the myocardium during the recovery stage.