In simple terms heart rate variability (HRV) is the variation in time between beats of the heart. Although we often think of the heart beating like a well-paced metronome, a healthy heart is always responding to its environment and is able to speed up or slow down as needed - two consecutive beats may be a second apart, the next two beats may be 0.8 seconds apart, etc.
The autonomic nervous system plays a large role in modulating HRV, with a kind of tug-of-war between the sympathetic (fight or flight) and parasympathetic (rest and digest) branches increasing or decreasing heart rate in response to stimuli.
But what does this have to do with health? Well, the autonomic nervous system is made up of all the tiny nerve branches that go everywhere in your body to regulate processes that you don’t even think about. When the nervous system is affected by illness or injury, it will have a more difficult time regulating these automatic processes, including your ability to modulate your heart rate.
As an example, we can think of someone that has had uncontrolled diabetes for a long time. We know that over time uncontrolled diabetes can damage nerve fibers. As the damage to nerve fibers worsens, this would impair the ability of the autonomic nervous system to function at its best and thereby lead to challenges in modulating he speed up/slow down ability of the heart. Heart rate variability would be impacted.
Heart rate variability can be hard to interpret as there are many factors that affect it, including age and different medical conditions. This has made it difficult to use in traditional clinical encounters, but it has become more commonly accessed via consumer-level devices. For a lot of people, it can be a starting point to monitor the health of their body and mind.
If you have questions or concerns about your HRV data, it may be helpful to check in with your primary care provider to ensure that you are proactive about your health. If you are having difficulty connecting with your doctor, Empirical Health can help!
