Dynamics of heart rate variability and ventricular ectopic activity in ivabradine-treated patients with chronic heart failure

Aim. In patients with chronic heart failure (CHF) of ischemic aetiology, to assess the dynamics of heart rate variability (HRV) and ventricular ectopic activity during the complex, ivabradine-including therapy. Material and methods. In total, 90 patients with CHF and stable angina pectoris ;were examined. All participants were randomised into three equally sized groups: Group 1, receiving perindopril and ivabradine, as a part of the complex treatment; Group 2, receiving perindopril, bisoprolol, and ivabradine; and Group 3, receiving perindopril and bisoprolol. The therapy duration was 6 months. At baseline and in the end of the treatment phase, the following parameters were assessed: HRV measures (mean 24-hour hear rate (HR), SDNN, triangular index (HRVti), and mean weighted variation of rhythmogram (MWVR)); mean 24-hour QT, QTc, QTc dispersion (QTcd), and ventricular extrasystolia (VE). Results. The treatment was associated with a significantly greater reduction of mean 24-hour HR in Groups 1 and 2 vs. Group 3 (p<0,001). In Group 3, the SDNN increase was significantly lower than in Groups 1 and 2 (p<0,001), where SDNN values were similar (p=0,091). Group 3 also demonstrated a significantly lower increase in MWVR, compared to Groups 1 and 2 (p<0,001). This parameter was similar in Groups 1 and 2 (p=0,065). The increase in HRVti was more pronounced in Group 2 than in Groups 1 and 3 (p<0,001). The reduction in the total 24-hour VE number was significantly more pronounced in Group 2 than in Groups 1 and 3 (p<0,001). The dynamics of 24-hour QTc and QTcd was similar across three groups. Conclusion. Including ivabradine in the complex therapy of patients with CHF and stable angina pectoris was associated with improved HRV, no marked QTc or QTcd changes, and a moderate preventive effect on VE.