On September 19th, Optimal HRV teammates Dr. Inna Khazan and Dr. David Hopper will present a three-hour Pain Management & Heart Rate Variability presentation. This comprehensive training will equip you with the necessary knowledge to understand the complex relationship between pain and heart rate variability. In the lead-up to this, we'll explore some of the basics of pain in a series of blog posts. You can learn more about the training and sign up here.
Pain is a complex and subjective experience that involves sensory, emotional, and cognitive components. Pain is "an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage" (International Association for the Study of Pain, 2011). Pain can have different causes, types, and intensities, and it can affect various aspects of a person's life, such as physical functioning, psychological well-being, and social relationships.
The autonomic nervous system (ANS), which regulates the body's involuntary functions, such as heart rate, blood pressure, digestion, and sweating, is a remarkably adaptable system. It has two branches: the sympathetic nervous system (SNS), which prepares the body for action and stress, and the parasympathetic nervous system (PNS), which promotes relaxation and recovery. This adaptability is reflected by the heart rate variability (HRV), which is the variation in the time intervals between consecutive heartbeats. A higher HRV indicates a more flexible and adaptive ANS, while a lower HRV indicates a more rigid and stressed ANS.
Pain can influence the ANS and the HRV in diverse ways, contingent on the characteristics of the pain and the individual. Acute pain, typically caused by tissue damage or injury, tends to activate the SNS and reduce the HRV as the body mobilizes resources to cope with the threat. Chronic pain, which persists beyond the average healing time or occurs without a clear cause, can have more variable effects on the ANS and the HRV. These effects depend on factors such as the intensity, duration, location, and meaning of the pain and the person's psychological and emotional state, coping strategies, and social support.
Some studies have found that chronic pain is associated with lower HRV, indicating a chronic stress response and a reduced ability to regulate emotions and cope with challenges. Other studies have found that chronic pain is associated with higher HRV, indicating a chronic activation of the PNS and a reduced ability to respond to external stimuli and engage in social interactions. (Koenig et al., 2016; Kemp et al., 2010; Chalaye et al., 2019).
In this blog post, we have introduced the topic of pain and heart rate variability and how they are related to each other and the autonomic nervous system. We have seen that pain can have different effects on the ANS and the HRV, depending on the nature and context of the pain and the individual. Understanding these effects not only helps us better assess and manage pain but also holds the potential to significantly improve the quality of life and well-being of people living with pain.
References:
Chalaye, P., Goffaux, P., Lafrenaye, S., & Marchand, S. (2019). The many faces of heart rate variability in pain. Journal of Pain Research, 12, 3119-3133.
International Association for the Study of Pain. (2011). IASP taxonomy.
Kemp, A. H., Quintana, D. S., Gray, M. A., Felmingham, K. L., Brown, K., & Gatt, J. M. (2010). Impact of depression and antidepressant treatment on heart rate variability: A review and meta-analysis. Biological Psychiatry, 67(11), 1067-1074.
Koenig, J., Jarczok, M. N., Ellis, R. J., Hillecke, T. K., & Thayer, J. F. (2016). Heart rate variability and experimentally induced pain in healthy adults: A systematic review. European Journal of Pain, 20(3), 301-314.