1. What Is HRV
HRV stands for heart rate variability, which means the variation in the time interval between heartbeats. The heart rate is produced by the SA node generating an electrical impulse that causes the heart to contract. This physiological phenomenon is
deeply related with the autonomic nervous system. The autonomic nervous system is influenced by an external and internal circumstances and this influenced autonomic nervous system also has an effect on the heart rate variability reflecting the biofeedback. Therefore, if the heart rate variability is analyzed, the autonomic nervous system function, and stress and health status can be indicated. 

2. Why Do the Repeated Measurements Come with Different Test Results?
We mainly manufactures diagnostic equipment that measures the heart rate variability [HRV], analyzes the sympathetic and parasympathetic nerve in the autonomic nervous system [ANS], and indicates the stress status. Once stressful circumstance influences the ANS, it also has an effect on a heartbeat. Then, this influenced heartbeat becomes irregular, and is called heart rate variability [HRV]. On the other hand, if the HRV can be detected, the ANS influenced by the stressful circumstance can be also tracked back. In this way the stress status will be able to be analyzed. Medicore equipment indicates the analyzed stress status based on the HRV so that patients can understand their body condition. 

We obtain the HRV from consecutive heartbeats. However, the Heartbeats are not regular, and due to this phenomenon, the HRV has a dynamic variation. Since the pattern of heartbeats changes easily, chances are that each test has the various results. 

The cycle of heartbeats continuously changes every moment by sensitively responding to the internal and exterior  ircumstance such as changing position, emotion change, and stress. For example, if you go hiking your heart rate increases. If you are scared of your cat suddenly jumping into your face at night, your heart rate also increases. Those examples mean that your heartbeats can easily change even from a light stimulation. 

According to the clinical research, those who consistently work out and have a regular life pattern in their 20’s and 30’s usually have various fluctuations in their HRV, which means that their ANS is well activated and help them to quickly recover from stressful situations. However, if the HRV has less variations and remains flat on the graph, the HRV status is not good and healthy. For example, people with medical conditions such as diabetes, myocardial infraction, arteriosclerosis, or obesity or who are aged have monotonous HRV. 

If you don’t comply with the instructions below and have multiple tests, the results will be also unusual.
– Take a rest for about 10 minutes before the measurement 
– Do not move or talk during the measurement 
-The measurement is recommended to be conducted in the morning 
-Take a normal breath and refrain from taking a deep breath during the measurement 
-Do not keep your eyes closed during the measurement 
-Smoking, drug, coffee, or any food are prohibited at least 3 hour before the measurement 
-Alcohol is prohibited at least 24 hour before the measurement 
-Nail polish will lead to the inaccurate test result 

3. Why Should Left Index Finger Be Used for Measurement? 
When clinical research was conducted, left index finger was used for obtain the reference data. Therefore, the left index finger is recommended for the measurement. However, right index finger can be still used in case that there is no choice. 

4. How Does the Irregular Heartbeats Mean the Healthy Status? 
It seems as if a heart regularly beats up but actually heartbeats are not regular. If it has a dynamic variation, it means the healthy status. Recently a lot of researches discovered that the heart rate variability and autonomic nervous system are deeply related and the normal pattern of heartbeats are supposed to be irregular. It is because the autonomic nervous system changed by internal and external circumstances has an effect on heartbeats. At this point, if the autonomic nervous system well responds to the circumstances, the heart rate variability is also dynamic. In1996, the European Society of Cardiology proved that the various fluctuations of the heart rate variability mean the healthy status. 

5. DoWe Know Everything about the Autonomic Nervous System by Analyzing the Heart? 
It is impossible to know everything by analyzing the heart, but this organ is under the control of sympathetic and  parasympathetic nervous system. Since the heart sensitively reflects the autonomic nervous system activity and R-R interval, it is possible to know the activity and function of the autonomic nervous system. 

6. How Do We Know the Balance of Autonomic Nervous System?
The heart rate variability [HRV] can be analyzed by the two methods (Time Domain Analysis and Frequency Domain Analysis). Using the frequency domain analysis, the balance of the autonomic nervous system can be indicated. Since it turned out that the low frequency clinically indicates the sympathetic nervous system and the high frequency clinically does the
parasympathetic nervous system, the HRV became a representative parameter for the autonomic nervous system. In this regard, we can know the balance from a ratio of sympathetic and parasympathetic nervous system. 

7. Can Arrhythmia Be Detected by the HRV Test? 
Normal heart rate would be from 60 to 90 with consistent contraction. However, in some cases, the heart skips contraction or
it happens too fast. This phenomenon is called extra systole contraction. When the extra systole contraction is detected during the HRV measurement, abnormal heartbeats will be automatically counted. Arrhythmia can be deeply related with the abnormal heartbeats. When the R-R interval gets shortened or longer than the normal range, there is a possibility of  arrhythmia. However, the extra systole contraction can happen when the sympathetic nervous system gets dominant bystress, alcohol, or caffeine. Also, arteriosclerosis, myocardial infarction, hypertension, cardiovascular diseases and pneumonia can cause the extrasystole contraction. 

8. In Which Department Is the HRV Test Used?
Our HRV test has been used in internal medicine, family medicine, psychiatry, otolaryngology, neurology, pain management, and examination centers. It can be also applied to dysfunction issues such as chronic fatigue, depression, anxiety disorders,stress, migraine, dizziness, immunity disorder, inldigestion, diabetic, and autonomic neuropathy. Especially, it is possible to objectify early stage before it becomes chronic and to keep patients in a healthy status.

– Stress Clinic: depression, anxiety disorders, somatization disorder, sleep disorder, and other disorders related with stress. 
– Chronic Fatigue: chronic fatigue syndrome caused by mental and physical issues.
– Endocrinology (diabetes mellitus): diabetes mellitus comes with multiple complications caused by autonomic nervous system
  dysfunction.
– Obesity Clinic: stress-related obesity, eating disorder, and systematic management of autonomic nervous system dysfunction.
– Anti-aging Clinic: diagnostic information on menopausal transition, and prediction of cardiovascular diseases. 
– Studying Management: learning anxiety, stress management, and attention deficit 
– Cardiology: Arrhythmia, myocardial infarction, and intensive care of cardiovascular issues.   
– Dysfunction Clinic: various symptoms that don’t appear abnormal on examination results. 
– Hypertension Clinic: evaluation of cardiovascular autonomic regulation function, and prognosis of pre & post
  antihypertensive medicine.
– Examination Center: adult disease prevention, neurological disease, sudden death prevention clinic
– Pain Management: autonomic nervous system function measurement, and prognosis of pre & post treatment such as manual
  therapy 

9. How to Find the Clinical Papers on HRV?
– Go to ‘www.ncbi.nlm.nih.gov/Pubmed’ and search by ‘heart rate variability’
– You will be able to find more than 50,000 cases
– You can find more information if you go to ‘www.ncbi.nlm.nih.gov/Pubmed’
– We also have more than 300 papers related with our equipment. 

10. What Are the Benefits Compared to Competitors?
1) Asia Reference Data 
We studied for two years with 8 university hospitals and established the HRV reference standard for Asian people. The data are applied to our equipment for the first time and we provide more accurate test result. We have also updated the HRV reference every 10 years, and the collected data reached 200,000.
2) We are the first company that have researched and developed the HRV since 2000 in Korea.
3) We have more than 95% of market share in Korean hospitals. (Clinical Accuracy for diagnosis is important)
4) We have over 300 clinical papers where our equipment is used, and multiple patents.
5) We have the reference standard for Asian and western people
6) Automatic interpretation and comments provided. (Only the company with a consistent clinical experience can provide)
7) Our medical equipment was granted CE certificate and FDA clearance.
8) 1 minute measurement is provided based on 200,000 data analysis. 

11. Do Western People and Asian People Have a Different Test Result?
There are many differences between Asian people and Western people in HRV results, which measure subtle variations in the heart. Asian people tend to have lower values in terms of the standard deviation of measurement. Some doctors insist that it
happens due to the difference of diet and heart size. Even men and women have a different heart size. Men’s heart size is
around 135/m2 and women’s heart size is around 110/m2. Furthermore, professional athletes have a bigger heart than the one from normal people. According to the clinical research, Western people tend to have a stronger autonomic nervous system
function and stress resilience. Therefore, Western and Asian reference must be correctly applied to get an accurate test result. 

12. What Are the Recommended Condition and Caution for Measurement?
1) Room condition and caution
– Patients must feel comfortable for the measurement 
– Room temperature must be maintained and noise should be insulated.
– Before the measurement, patients must take a rest at least for 5 minutes.

2) Exclusions 
Since patients with arrhythmia have an abnormal heart rhythm, it is impossible to evaluate with the HRV the autonomic nervous system function or stress status. Other than arrhythmia, patients with asthma, and heart disease are not suitable for this measurement. When someone’s heart rate is too high or too low, even if he or she doesn’t have any disease above, have
them relaxed until they have a normal heart rate back before the measurement.

3) Cautions
1. You are invited to have a comfortable position before the test and do not move or talk during the test.
2. Do not have a deep breath but have a normal one. If you already walk or work out, you must take a rest at least for 10
   minutes before the test.
3. Caffeine, smoke, drugs are not allowed at least 2 hours before the test
4. Sit on a chair and place the left hand on the left lap during the test.  
5. Finger nail must remain intact. Please remove nail polish for the test.
6. Test result will not be accurate right after eating food.
7. Patients must stay relaxed. Refrain from deep breath, coughing, sigh, or yawn.
8. Keep your eyes open.
9. It is recommended that the test should be processed in the morning. The biofeedback is usually accurate in the morning.
  The fatigue is accumulated and it might have an effect on the result afternoon.
10. The test should be processed at the same time on which the first measurement is implemented.
11. The intended deep breath can be regarded as a healthy HRV status. Therefore, test result will not be accurate 
12. In terms of pregnancy, the heartbeats of fetus can be also detected. Furthermore, since hormone change has an effect on
  the autonomic nervous system, the result is not 100% accurate. 
13. How Much Time Does the Test Require?
We provide the 1 minute, 3 minute, and 5 minute mode. The test result will be the most accurate with the 5 minute mode but some patients have a hard time having the 5 minute measurement. In this case, we recommend the 3 minute mode. Through the clinical trials, the 3 minute mode is as accurate as 5 minute mode. Furthermore, we analyzed the data of 200,000 cases and developed the 1 minute mode using an A.I algorithm. 

14. What Is the Correlation between Stress and Heart Rate Variability?
Consistent stress reduces the self-control of homeostasis (Main Function of Autonomic Nervous System). Stress causes the cortisol to be secreted, the immune system to get weakened, and break the balance of the autonomic nervous system. In this case, body response to the external circumstance gets debilitated, and there is a high possibility of getting various diseases from simple fatigue to cardiovascular issue. Especially, the autonomic nervous system dysfunction comes with a short distance of R-R interval.   

15. What is the difference between HRV and ECG?
The HRV (Heart Rate Variability) test is an analysis of R-R interval that indicates the autonomic nervous system and stress
status. On the other hand, ECG (Electrocardiography) is a recording of P, Q, R, S, and T waves from the heart’s electrical activity
through repeated cardiac cycles. It can be used for arrhythmia, myocardial infraction, and cardiac issues.