Heart rate variability is a measure of the autonomic nervous system and is widely regarded as one of the best objective indicators of physical health and determination of physical readiness. It can be seen that the influence of normal heart rate variability on people is self-evident. So what is heart rate variability?
What is heart rate variability
Heart rate variability (HRV) refers to the changes in the difference of the heartbeat cycle from time to time. It contains information on the regulation of the cardiovascular system by neurohumoral factors, so as to determine its condition and prevention of cardiovascular diseases. It is a prediction of sudden cardiac death and arrhythmia. A valuable indicator of sexual events.
For example, if our heart rhythm is 60 beats per minute, we don’t actually beat once per second. There may be 0.9 seconds between two beats, and there may be 1.15 seconds between the other two beats. The greater this variability, the easier it is for the body to prepare for a high level. These time intervals between two consecutive heartbeats are called RR intervals and are measured in milliseconds.
At present, the analysis of HRV mainly adopts time domain analysis method, frequency domain analysis method and nonlinear analysis method.
How does heart rate variability occur?
Although HRV appears as a function of heart rate, it actually originates from the human nervous system. The human autonomic nervous system controls this involuntary aspect of physiology. It has two branches, namely the parasympathetic nerve and the sympathetic nerve.
The branch of the parasympathetic nerve processes input from internal organs, such as slippage or growth of nails and hair, which causes a decrease in heart rate.
The compassionate branch reflects responses to stress and exercise, etc., and increases the heart rate
Heart rate variability comes from these two competing branches, sending signals to the human heart at the same time. If the human nervous system is in a balanced state, the parasympathetic nervous system will continue to tell the human heart that the heart beats slowly, while the sympathetic nervous system makes the human heart beat faster. This will cause a person’s heart rate to fluctuate: HRV.
Schematic diagram of sympathetic and parasympathetic nerves
What is a normal HRV?
Since HRV is affected by factors such as gender, age, and environment, most standards are for reference only. Take age as an example
It can be seen that with age, HRV will drop sharply. The middle 50% of the 20-25 age group usually have an average HRV of 55-105, while the average HRV of the 60-65 age group is between 25-45.
Although the above figure shows that it belongs to the category of “normal HRV” technically, it is much more complicated to answer “What is good heart rate variability?”
Application of heart rate variability
At present, the main application of HRV is to monitor cardiovascular diseases
(1) Hypertension: The pathogenesis of hypertension is complex, but sympathetic hyperfunction is an important part of it. Especially in the early stage of the disease, LF is higher than normal people, while HF is lower than normal people. The diurnal changes of LF in hypertensive patients disappear, while HF remains elevated at night, suggesting that the regulation mechanism of sympathetic center is not good.
(2) Myocardial infarction: Sympathetic nerve hypertonia is often 30 minutes after myocardial infarction, especially when the anterior wall myocardial infarction, the inferior myocardial infarction may be vagal hypertonia. For example, patients with infarction use SD as an indicator, and it is found to be generally reduced. In the prognostic observation, the mortality rate of SDNN>50 ms is low, while the mortality rate of SDNN<50 sdnn=””>100 ms is about 5 times.
(3) Prediction of sudden cardiac death: Most of sudden cardiac death caused by arrhythmia is caused by ventricular tachyarrhythmia. The decrease in HRV is due to the weakening of parasympathetic nerve activity and the increase of sympathetic nerve activity. Reduce the threshold of ventricular fibrillation, so HRV has a certain significance for the detection of sudden cardiac death.
(4) Coronary heart disease: The HRV circadian rhythm of patients with coronary heart disease is weakened, especially when the vagus nerve excitement suddenly changes to sympathetic nerve activation at 5-6 am, LF increases, HF decreases, and the LF/HF ratio increases. At this time, plasma catecholamines increase. , Myocardial oxygen consumption also increases, which can trigger cardiac accidents, which reflects that HRV is indeed related to coronary ischemia.
(5) Congestive heart failure: Heart failure is often accompanied by elevated plasma catecholamines, which is related to the severity of the disease. HRV decreases during heart failure, which may be due to increased sympathetic activity and weaker parasympathetic activity
At present, the monitoring of heart rate variability has been widely used in smart watches. Among them, Shenzhen Weiyi Po Technology Co., Ltd. was established in 2011 and has been deeply engaged in the field of health smart watches. Yipang has applied medical monitoring technologies such as ECG, blood oxygen, heart rate variability, and scientific sleep in smart watches. Veepo has integrated the above technologies into Veepo Watch RIG. Veepo Watch RIG will always pay attention to the health of the wearer.
With the vision of “maintaining the physical health of hundreds of millions of people”, Shenzhen Weiyipo Technology Co., Ltd. is committed to scientific and technological innovation and application of data monitoring of human activities, physiological functions, and medical assistance. After 8 years of technological precipitation, Wei Yi Po is far ahead in human activity and health monitoring technology. Its research results have obtained more than 30 domestic and foreign invention patents. The data accuracy, scientificity and stability of its various wearable solutions Highly recognized and trusted by the market.