Background/Aim. Depressed heart rate variability (HRV) indicating autonomic
disequilibrium and propensity to ventricular ectopy can be useful for risk
stratification in patients following acute myocardial infarction (AIM). The
aim of the study was to assess heart rate variability as a predictor of
allcause mortality in post-infarction patients. Methods. We analyzed the
24-hour electrocardiographic (ECG) recordings of 100 patients (80 males)
during hospitalization for AIM. The mean age of patients was 56.99 + 11.03
years. Time domain heart rate variability analysis was obtained from 8 to 13
days after index infarction by mean of a 24- hour ECG recording, and the
calculated parameters were: standard deviation of all normal to normal RR
intervals (SDNN), RRmax-RRmin (difference between the longest RR interval and
the shortest RR interval), mean RR interval. We also analyzed ventricular
premature complexes from the ECG data. The patients underwent clinical
evaluation, laboratory tests and echocardiography. Results. Within a oneyear
follow-up period 11 patients experienced death, 10 of them because of cardiac
reason and one because of stroke. There were significantly lower values of
SDNN (60.55 ? 12.84 ms vs 98.38 ? 28.21 ms), RRmax-RRmin (454.36 ? 111.00 ms
vs 600.99 ? 168.72 ms) and mean RR interval (695.82 ? 65.87 ms vs 840.07 ?
93.97 ms) in deceased patients than in the survivors, respectively (p <
0.01). The deceased patients were of higher mean age, with lower left
ventricular ejection fraction (0.46 ? 0.05 vs 0.56 ? 0.06 in survivors), and
more frequent clinical signs of heart failure and ventricular ectopic
activity (> 10VPCs/h; p < 0.01). Multivariate Cox analysis showed that SDNN
was a significant, independent predictor of all-cause mortality in
postinfarction patients. The other independent predictors were clinical signs
of heart failure - Killip class II and III and ventricular ectopic activity.
Conclusion. Depressed HRV is an independent predictor of mortality in
post-infarction patients and may provide useful additional prognostic
information in non-invasive risk stratification of these patients.
Risk stratification in advanced heart failure using lorenz plot indices of heart rate variability
