Analysis 5-min and 24-hours protocols are recommended for HRV examination.

In 12 hours before the examination all the drugs need to be repealed. The patient should not have alcohol or coffee and avoid any stresses (mental or physical). ECG-recordings should be obtained between 9 and 12 a.m. in comfortable environment (about 22 C). Talking is not recommended.

To exclude the possibility of mental influence on HRV via autonomic regulation mechanisms some specialists demonstrate neutral movies while examination.

First examination evaluates the basic regulation system characteristics of the patient. It is hold in comfortable conditions when patient position is supine or sitting. Later depending on the aim of the examination an additional recording may be made in the mental and physical stress conditions or during pharmacological or autonomic tests.

The Most Frequently Used Protocols

1. Active tilt - test
2. Passive tilt - test
3. Hand dynamometers
4. The recording with a fixed frequency of respiration
5. Autonomic tests
6. Pharmacological tests
7. Mental tests

For any of the protocols the ECG-recording registration is carried out on the times intervals providing realisation of the chosen protocol. For the 5 - min protocol this time is 7 minutes. The first minute is used not for examination, but for the patient's adaptation to the new conditions. The examinations are performed between the 2^nd and 6^th minutes and the 7^th min is used for blood pressure measuring.