It is a well known fact that decrease in the Parasympathetic activity directly correlates with the damage of Parasympathetic receptors that occurs as a result of any disease. The goal of Autonomic Function testing is to recognize the stage of pathological developments by assessing the level of Parasympathetic activity.
For example, if parasympathetic activity is within the norm, level of SNS activity is not clinically relevant. However, in instances where PSNS is decreased, it is useful to know what's going on with the SNS activity. For example, in cases of acute Myocardial Infarction, stress, pain, or acute intoxication, the SNS activity increases while PSNS activity decreases. Low SNS and PSNS activity can be seen in cases such as degenerative joint disease in the elderly and beta-blocker overdose.
Another aspect of Autonomic Function Testing based on Heart Rate Variability analysis is Risk Stratification of Sudden Cardiac Death. It's most effective when combained with appropriate clinical and/or ECG evidence of cardiac arrest, like T-wave alteration, but sometimes even without it.
Quantitative Assessment of ANS based on heart rate variability analysis has been the subject of intensive research for the past four decades. Currently multiple facets of its theoretical and practical value encourage numerous cutting-edge investigational studies in both basic and clinical research. However, for many years this method has remained the privilege of research laboratories, and was not accessible to medical practitioners, and only recently was recognized for its effectiveness in clinical use by the FDA, AAMI, ANSI, and a number of health organizations and insurance companies.
Intellewave technology is unique in its ability to automatically differentiate between Sympathetic and Parasympathetic influences on R-R intervals variability regulation mechanisms by using proprietary patented method based on Artificial Intelligence theory. Such method did not require any source of information other than R-R variability.
Hence, we included here an overview of theoretical and practical aspects of ANS assessment based on HRV, courtesy of Alexander Riftine,PhD, a distinguished investigator recognized worldwide for his contribution in heart rate variability research.
This theoretical overview covers results of Dr. Riftine’s multiple investigational projects, uses statistical data accumulated over the period of 25 years, and incorporates findings of other published research studies in Heart Rate Variability analysis and ANS assessment. To illustrate typical cases of ANS reaction to controlled exercises, the author selected results from patients tested with Intellewave system, as this product is currently part of U.S. medical market.