Unexpected heart rate variability complexity in the aging process of arrhythmic subjects

In the present work we applied the multiscale sample entropy (MSE) calculation in RR time series of healthy subjects as well as patients with ventricular arrhythmia (VA) and previous myocardial infarction (MI) distributed in different age groups. We explored the hypothesis of complexity reduction in aging and disease. Our results showed that in the arrhythmic patient, complexity decreases with age increment as well as in healthy subjects, however no significant differences were found in the comparison of healthy and non-healthy older group.