Heart Rate Variability

UntitledThe heart does not beat steadily and the interval between each heartbeat varies, as does the frequency. This indicates that flexibility is necessary to adapt to certain environmental stimuli and challenges such as reacting to stressful situations.

Heart rate variability (HRV) is therefore an ideal parameter to detect states of stress within the body and mind, and resolve them by means of stress reduction. HRV allows for stress analysis to be performed on four levels consisting of 13 parameters.

These parameters are grouped as follows:

  • The Vegetative nervous system or relation of sympathetic and parasympathetic nervous system and general overall energy
  • Regulatory ability of the systems with acute and chronic stress parameters
  • Combined view of heart rate variability (HRV) plus extra systoles or contractions showing the stress state of a person with six parameters and their correlation to the Psycho-Neurological-Endocrine-Immune system (mind, nerves, hormones, immune system)

It has only been five decades since scientists began to alter their long-held belief that the human body’s cells, tissues and organs, particularly the heart, strive to maintain a constant static or steady state.

“We now know that the normal resting rhythm of the heart is highly variable rather than being monotonously regular, which was the widespread notion for many years,” write the authors of a new article slated to appear in the January issue of Global Advances in Health and Medicine (GAHM), a professional journal.

Heart rate variability, the change in the time intervals between adjacent heartbeats, is directly related to the body’s interdependent regulatory systems and ultimately, their efficiency and health.

Although generally the greater the HRV, the better, they note that too much variability, or instability “such as arrhythmias or nervous system chaos is detrimental to efficient physiological functioning and energy utilization… “Too little variation indicates age-related system depletion, chronic stress, pathology, or inadequate functioning in various levels of self-regulatory control systems.”

The GAHM article cites much of the pivotal heart rate variability research since 1965, when HRV began to be recognized for its importance in indicating or predicting various risk factors.

Among these are fetal distress, autonomic nervous system dysfunction, heart disease, anxiety, depression and asthma among other health conditions.

Many studies, including some conducted by McCraty and others at HMI, correlate an optimal level of HRV, or HRV coherence and coherence training, to a variety of benefits. Among the results of these studies were enhanced cognitive function in a range of age groups and greater functional capacity in heart-congestive patients.

Improvements were demonstrated in a study employing coherence training with a group of middle school students with attention-deficit hyperactivity disorder. Other improvements were shown in their short- and long-term memory, ability to focus and behaviours at home and school.

A range of positive health-related outcomes also has been demonstrated in studies with correctional officers who participated in coherence training, McCraty and Shaffer explain.

In one study conducted by McCraty, correctional officers improved their blood pressure, total cholesterol and fasting glucose levels and reduced overall stress and fatigue. Similar results were achieved with police officers.