Insights from the study of heart rate variability

Annu Rev Med. 1999;50:249-61. doi: 10.1146/


Indices of heart rate variability (HRV) provide a window onto autonomic modulation of the heart. HRV indices, determined in either the time or frequency domain, are closely related and reflect parasympathetic, mixed sympathetic, and parasympathetic and circadian rhythms. In population studies, decreased HRV has had predictive value for mortality among healthy adults. It is a well-established risk factor for arrhythmic events and mortality among post-myocardial-infarction patients but has only moderate sensitivity and specificity. Decreased HRV has had mixed predictive success in congestive heart failure. Reduced HRV identifies diabetic patients with autonomic neuropathy. HRV in combination with other risk stratifiers, e.g. ejection fraction, can identify cardiac patients at especially high risk of mortality. Many but not all interventions associated with increased HRV are also associated with better survival rates.

Publication types

  • Review

MeSH terms

  • Adult
  • Arrhythmias, Cardiac / physiopathology
  • Autonomic Nervous System / physiology
  • Autonomic Nervous System Diseases / physiopathology
  • Cardiac Output / physiology
  • Circadian Rhythm / physiology
  • Death, Sudden, Cardiac / etiology
  • Diabetic Neuropathies / physiopathology
  • Heart Conduction System / physiology
  • Heart Failure / physiopathology
  • Heart Rate / physiology*
  • Humans
  • Mortality
  • Myocardial Infarction / physiopathology
  • Parasympathetic Nervous System / physiology
  • Predictive Value of Tests
  • Risk Factors
  • Sensitivity and Specificity
  • Survival Rate
  • Sympathetic Nervous System / physiology