vlrMemos and Telemonitoring |

Although the heart is relatively stable, the time between two heartbeats (R-R interval) may be different. The HRV measures the fluctuations in the cardiac system over the time. The R-R intervals are generally given by the electrocardiogram (ECG).

The variability of the heart rate is a very important parameter, because this parameter is:

- A reflection of the autonomic nervous system.

- An excellent general health level indicator.

- A predictor of the hypertension.

- An indicator of stress and fatigue.

Its decrease is a sign of risks of cardiac events.

Its interest is also demonstrated in the analysis of the recovery of the athletes.

The Analysis in time and frequency domains allow to quantify the HRV.

The short-term and long-term variabilities will be computed.

Optionally, with the modules that support the ECG, we will perform at the readings of the ECG recordings, calculations in the time domain and in the frequency domain:

- In the time domain, we will calculate the recommended standard deviations by the Task Force.

- In the frequency domain, we will do the spectral analysis (spectral density as a function of the frequency) from the Fast Fourier Transform performed on the signal (RR intervals as a function of the time) by presenting four spectral components:

- The high frequencies (HF).

- The low frequencies (LF).

- The Very low frequencies (VLF).

- The ultra low frequencies (ULF).

From the arterial blood pressure waveforms, one can extract parameters like:

- The Systolic Blood Pressure (SBP).

- The Diastolic Blood Pressure (DBP).

- The Mean Blood Pressure (MBP).

- The Pulse Pressure (PP).

The Blood Pressure Variability (BPV) measures the fluctuations in the Systolic Blood Pressure (SPB) over the time.

Optionally, as for the Heart Rate Variability (HRV), with the modules supporting the arterial blood pressure waveforms, we will perform during the reading of the recordings, calculations in the time domain and in the frequency domain.

The short-term and long-term variabilities will be computed.

Unlike the HRV, a significant increase in BPV is a risk factor of cardiovascular events and strokes.