An Extra-Systole Arrhythmia Lowers the Scaling Exponent: DFA as a Beneficial Biomedical Tool

We made our own DFA (detrended fluctuation analysis) program. We applied it for checking characteristics for the heartbeat of various individuals. Healthy subjects showed a normal scaling exponent, which is near 1.0 (ranging 0.9 to 1.19 in our own temporary guideline). This is in agreement with the original report by Peng et al. long time ago. In the present study, we investigated the person who has an extra-systole heartbeat, which is so called as PVCs (premature ventricular contractions), and revealed that their arrhythmic heartbeat exhibited a low scaling exponent (around 0.7). Alternans, which is the heart beating in period-2 rhythms, exhibited a much low scaling exponent (around 0.6). We may conclude that if it would be possible to make a device that equips a DFA program, it might be useful to check the heart condition, and contribute not only in nonlinear physics but also in biomedical fields; especially as a device for health check, which is applicable for people who are spending an ordinary life, before they get seriously heart sick.