Assessment of frequency components of ECG waveform variability: Are there prospects for research into cardiac regulation processes?

This brief review discusses the potential and prospects of using the electrocardiogram (ECG) signal directly for frequency analysis to study the processes of cardiac regulation. The advantage of the ECG signal over the generally accepted frequency analysis of the RR series is its higher sampling rate: 1000 samples per second (sps) for ECG signal vs. 4 sps for RR series. This may be important, first of all, when analyzing the interaction of cardiac regulation processes with other periodic processes in the body, such as the activity of neural circuits in the brain.