Aim. To identify the features of Holter ECG monitoring indicators and structural and functional cardiac remodeling in patients with Q-wave myocardial infarction (Q-MI) in the acute period after primary coronary intervention (PCI).

Materials and methods. In total, 78 patients with acute Q-MI were divided into 2 groups: group 1 – patients (n = 42) who underwent PCI during the acute period of Q-MI (median age 62 (52; 71) years); group 2 – patients (n = 36) who received standard pharmacological therapy (median age 67.5 (61.5; 75.0) years).

Results. The mean corrected QT interval (QTc) was 404 (391; 423) ms and 418 (397; 445) ms in groups 1 and 2, respectively. Group 1 demonstrated a significantly lower incidence of left ventricular (LV) akinesia (14 vs. 21 cases, p = 0.03), a significantly higher number of patients with normal ejection fraction (EF) (30 vs. 19, p = 0.01), and fewer patients with reduced EF (1 vs. 8, p = 0.01). A trend toward a shorter QTc was observed in group 1 (by 3.35%, p = 0.05). QTc duration correlated with the number of ST-segment episodes (r = 0.36, p < 0.05), the duration of tachycardia episodes (r = 0.37, p < 0.05; r = 0.43, p < 0.05), the number of premature ventricular contractions (PVCs) during the day and night (r = 0.52, p < 0.05; r = 0.51, p < 0.05), and the number of single and paired PVCs (r = 0.49, p < 0.05; r = 0.45, p < 0.05). The presence of LV akinesia correlated with episodes of supraventricular arrhythmias (r = 0.35, p < 0.05), while the presence of LV aneurysm correlated with the number of PVCs during both daytime and nighttime periods (r = 0.35, p < 0.05; r = 0.38, p < 0.05). In both groups, patients with significantly or moderately reduced heart rate variability (HRV) were observed: 13 vs. 16 (p = 0.2). In both study periods, an increase in the relative value of the very low frequency (VLF) component (>30 % of total power, TR) and a decrease in the high-frequency (HF) component (<15 %) were noted. The number of patients with RMSSD <20 ms was similar between groups: 19 (45 %) vs. 16 (44 %), p = 1.0.

Conclusions. In all patients with acute Q-MI, regulatory system tension was observed, characterized by predominance of the sympathetic component of HRV. A high proportion of the VLF component in total power indicated elevated psycho-emotional stress levels. Patients receiving standard pharmacological therapy demonstrated QTc prolongation and reduced autonomic nervous system flexibility compared with PCI-treated patients. In patients after PCI, the number of PVCs and ischemic episodes showed a direct relationship with QTc duration. Moreover, these patients had significantly fewer cases of LV akinesia, a greater number of patients with normal EF, and fewer cases of reduced EF compared with the drug therapy group.