Purpose: to estimate interrelations between heart
rate variability (HRV) and left ventricle ejection fraction
(LVEF) in patients after the acute Q-wave myocardial
infarction (Q-AMI).
Materials and methods: 9 6 m ale p atients i n t he
average age of 52.78±9.05 y. o. survived after the
primary Q-AMI were included into the study. The
diagnosis of Q-AMI was established in accordance
with the ESC criteria (2012). All patients underwent
Holter ECG monitoring (HMECG) with the estimation
of HRV and transthoracic echocardiography. HMECG
in all cases were performed in normal conditions,
on standard therapy without any specific restrictions
on 10–14 day of the Q-AMI and after the 6 month
of follow up. Standard therapy included antiplatelet
agents, beta-blockers, ACE inhibitors or ARB, statins
in individually matched doses, nitrates (if necessary) and amiodarone (if necessary). Interpretation of
HRV parameters was made in accordance with the
recommendations of the ESC working group and the
NASPE (1996) with estimation of SDNN, SDANN,
RMSSD and pNN50. As a decrease in the total
HRV, a reduction of SDNN≤100 ms was assumed.
Statistical analysis was performed using Office Excel
2007 (Microsoft Corp., USA) and STATISTICA version
6.0 (StatSoft, Inc., USA). Nonparametric ANOVA χ2
test was performed. Differences were considered
significant for p<0.05.
Results: Analysis of the features of the baseline
level of HRV and its dynamics by the 6th month
after the acute Q-AMI was carried out. It was noted
that level of the SDNN, SDANN and pNN50 values
increased on therapy by more than 20%, and the
rMSSD - more than 12%. To estimate of LV function, which exert their
influence on the dynamics of HRV in patients after
Q-AMI, LVEF was analyzed. In patients with reduced  HRV (SDNN<100 ms; mean SDNN 85.2±32.2 ms)
at 6 months of follow-up, were noted significantly
lower initial values of the LVEF (49.28±11.89% vs. 51.98±10.39%; p=0.038), compared with patients with
normal HRV (SDNN>100 ms; mean SDNN 110.6±28.0
ms). There was also a significant positive correlation
between baseline LVEF values and SDNN (R=0.21,
p=0.041) and SDANN (R=0.22, p=0.034) after the
6th month follow-up. Also, group of patients with a
significant baseline decrease in EF<40% (mean EF
32.96±5.34%) compared with patients with baseline
EF>40% (mean EF 54.23±8.77) were further analyzed.
It was noted that patients with significantly reduced
EF, at baseline, had reliably lower rates as SDNN (84.8±25.9 ms vs. 103.5±28.9 ms, p=0.035) and
SDANN (75.3±21.9 ms vs. 92.9±26.9 ms, p=0.038).
Conclusions: Group of patients with reduced
total HRV at 6 months of follow-up demonstrates
significantly lower initial values of the LVEF and there
is a significant positive correlation between baseline
LVEF values and total HRV level on 6th month of
follow-up. Low level of LVEF on 10–14 day of Q-AMI
may be consider as a 6-month predictor of decreasing
of HRV which in combination points to worsening of
prognosis for such category of patients.