1. HRV Reading Guide
Reading Basic Guide & CASES

2. < HRV Reading Guide>
1st, HR / SDNN
2nd, TP / LF / HF
3rd, LF / HF ratio
4th, Stress Index

3. SDNN (Standard Deviation NN or RR interval)
: Representative parameter that shows the Heart Rate
variable status
: Most important indicator of Autonomic Nerve function
evaluation
: Ex) Although ANS balance is good, it is evaluated as
the lowering activity of ANS and excessive stress state
if SDNN is still lowering level.
Lowering in SDNN
-Drop the function of ANS
Drop the function of body regulation
Lower in stress resistance
Lower in general health status

4. <Graph with the Heart Rate Variability>
Please explain with SDNN parameter.
Tacho
Histogram
RRV
SDNN
Healthy
irregular, complicate
wide, flat
wide, spread
30-100
Disease
simple, constant
narrow, sharp
concentrated at one spot
below 25

5. 2. Frequency Domain - TP / LF/ HF
: Evaluate the activity of SNS, PNS, ANS compared with
age, gender and normal reference.
: It may not be visible for SNS or PNS dominant clearly
because it is compared with the normal reference.
Check this evaluation at the ratio rate.
: Ex) ANS activity is lowered by the stress, and SNS is
highly dominant.
1. Check if SNS and PNS are below the normal.
2. SNS is higher than PNS when compared with each.
-> Express the rate as SNS : PNS.

6. 2. Frequency Domain - TP / LF/ HF
TP Lowering
VLF Lowering
LF Lowering
HF Lowering
* Decreased ANS function
* Lowered adaptability
* Decreased ability to
cope with the requirements
of continuously changing
environment
* 3-5min. measurment doesn’t have a significant meaning.
* Loss of energy
* Fatigue
* Insufficient sleep
* Lethargy
* Listless
* Chronic stress
* Aging
* Reduced electrical
stability of heart
* Functional *Indigestion

7. Clarify the balance of SNS and PNS
3. LF / HF Ratio
Clarify the balance of SNS and PNS
“ Autonomic Nerve System……. ?
Parasympathetic Nerve System
Sympathetic Nerve System
ANS
It is changing continuously.
▶ Only with SNS/PNS rate, it is not arguable.
2. If the central axis is rusted, the seesaw doesn’t move.
▶ Check the SDNN parameter.
3. Therefore, if SDNN is lowered, it is not activating in seesaw.
▶ Currently, if SNS/PNS has a balance, but it causes problems.

8. 3. LF / HF Ratio ▣ SNS:PNS = 6 : 4 (Best)
( In a healthy, it can be variable of SNS and PNS by a constant emotion. If one of them is not mostly higher, it is not saying that the balance is broken.)
KEY POINT
SDNN - NORMAL
SDNN - ABNORMAL
LF/ HF
BALANCE
Normal
Balance is good, but ANS activity is lowered. It can be possible to go bad if you have any stimulus from internal/external environment. It is necessary to improve the condition.
UNBALANCE
Temporary Case
LF Increase
: Temporary Stress State
HF Increase
: Relaxation or test after meal
As ANS activity is very lowered, the balance of SNS & PNS is not easy to be controlled to make it balance. Although the balance can be changed, but it can be keeping this condition constantly.

9. 4. Check Stress Index Evaluate the stress level ▣ Pressure Index :
-> Based on mean HR , SDNN activity, it is calculated the Pressure for Regulation System. As much as distance from the Normal,
the stress level is getting worse.
▣ Emotional State :
Decide by the balance of SNS & PNS
High – Anxiety, Irritation, Nervous, Panic,
Distractable, Hyper-arousal
Low – Slow mental speed, Hypo-arousal,
Lethargy, Chronic Neurasthenia

10. 5. Be noticed while reading the report!
- Check the Tachogram at the beginning stage
CASE #1. Respiration Control
SDNN,TP,LF,HF ,PSI = All normal
However, SNS in ANS balance is excessively high. It can be possible to show as the balance is broken instantly by the stress. You may measure the test again.
Throughout the respiration control with HRV Tachogram, it is seen that HR is changing in a regular pattern.
In this case, the change of respiration influences the HR and it is not easy to get the correct data.
(If the HR is changing by the respiration control, it will be getting a better result.)
Take a test again while the position is stable.

11. CASE #2. Abnormal HR in high quantity
Before evaluation, should be known as Tachogram is abnormal. It can be happening this result when she talked or moved, but also when she may have an arrhythmia.
It will be necessary to measure the test again for the analysis in detail.
Did the patient move or talk during the measurement?
Was the sensor working properly?
Was there any similar signal as like arrhythmia?
In case of 3), it will be necessary to get consultation with a doctor.

12. # CASE 8 CASE #3. Bronchial Asthma, allergy
It is found that tachogram of HRV is changing regularly, but its range is big.
In this case of patients, it is normal pattern that those who have bronchial asthma or allergy have the similar tachogram and also if the patient has a respiration control as inhaling or exhaling.