Chronic Disease and Heart Rate Variability – What's The Link?

Heart rate variability (HRV) based autonomic nerve system monitoring represents a revolution in healthcare. Measurement is a non-invasive test of autonomic nervous system (ANS) functioning. This helps us to start answering such questions as are you stressed?? Are you not able to recover from stress efficiently? Are you recovering from your day and what was the quality of your sleeo? Why you might have little energy? Why the chronic condition you have just keeps on getting worse! These things that have, historically, been difficult to prove, but are now possible with HRV technology.  HRV specifically looks to gauge the interaction between the two branches of the ANS, which controls much of the internal functioning in the body.  These two branches are called the sympathetic (SNS) and parasympathetic nervous systems (PSNS). Heart rate variability represents the cardiovascular control mediated by the autonomic nervous system and other mechanisms and looks to determine the interaction between the sympathetic (‘fight or flight’) and the parasympathetic (‘rest and digest’) parts.  This information can then be used to establish disease risk and understand why people may be having problems with their body, and then guide them towards lifestyle changes that could correct any unwanted imbalance between the two. For example, dominance in the Sympathetic Nervous System short term is great should you need to exercise, but long term can bring about many ailments and lead to an early death. Before we get into more detail there, lets learn a little more as to why this is the case. The autonomic nerve system differs from the voluntary system in that it is not under control of human intention, but rather operates automatically and involuntarily to support homeostasis and help maintain a relatively constant internal environment.  It is responsible for controlling such involuntary functions as digestion, respiration, perspiration and metabolism, as well as regulating blood pressure and heart rate. The ANS plays a large part in the regulation of bodily functions and assessing activity in the ANS can tell us about the body’s regulatory state. State 1: Active, scared, exercising, alert, on-guard, high fuel levels, high anxiety, catabolic – the system responsible is the SNS. The SNS reacts to challenge from the environment by increasing metabolic output. State 2: Relaxed, recovering, sleeping, eating, sexual, comfortable. System responsible is the PSNS. PSNS then think: rest, repair and growth. Anabolic. Restoration and conservation of energy. From understanding these physical states, it becomes clear that these two systems discharge to bring about opposing affects in the body. Therefore the natural homeostatic state of the body i.e. resting heart rate, resting level of stress hormones, 24 hour blood pressure, general digestive function, sleep pattern, cardiovascular risk etc is directly linked to which system is the dominant force.   Lets give some examples of physiological parameters controlled by the ANS: Heart rate Blood pressure Blood sugar fluctuations Digestive ability Temperature Immune strength Sleep quality Sexual functioning Activity brought about by PNS Stimulation: Prepares the body for rest and digestion Energy conservation Restoration and recovery Digestion and absorption of food Crying Resting/sleeping Activity brought about by SNS activity: Prepares body for emergency situations and the ‘fight or flight’ Allows body to “escape danger” through mechanisms below: Dilation of pupils of eye Increase in heart rate and force of contraction Redistribution of blood to muscles and periphery Increased respiratory rate Increased mobilisation of blood sugar Release of stress hormones adrenaline, noradrenalin and cortisol Reduction in digestion Thoughts and even subtle emotions influence the activity and balance of the ANS. The ANS interacts with our digestive, cardiovascular, immune and hormonal Systems. Negative reactions create disorder and imbalance in the ANS. Positive feelings such as appreciation create increased order and balance in the ANS, resulting in increased hormonal and immune system balance and a more efficient brain function.  As we move into further parts of this article, I will be going into more detail explaining the many links with health physically and mentally. But for now, hopefully you can start to understand how imbalances in the ANS can lead to chronic disease and in cases of present disease, make it much worse.         ]]>