There are over 1200 pages of published literature on the three VS Diagnostics tests.
Below please find a selection of representative articles:
The relationship of autonomic imbalance, heart rate variability and cardiovascular disease risk factorsThayer, JF, et al. International Journal of Cardiology. 2009
Briefly: The article reviews the evidence linking HRV to cardiovascular disease risk factors such as hypertension, obesity, family history and stress and finds that substantial evidence suggests that low HRV actually precedes the development of a number of risk factors. Furthermore, evidence indicates that improving risk profiles likewise improves HRV. The paper also proposes autonomic imbalance, as measured by HRV, as a framework with which to investigate the impact of various risk factors on cardiovascular disease.
Heart rate variability and first cardiovascular event in populations without known cardiovascular disease: meta-analysis and dose-response meta-regressionHillebrand, S., et al. Eurospace (European Society of Cardiology) 2013.
Briefly: Low HRV is associated with a 32-45% increase in the risk of a first adverse cardiovascular event even in those patients without a known history of cardiovascular disease.
Diabetes and cardiac autonomic neuropathy: Clinical manifestations, cardiovascular consequences, diagnosis and treatment Balcioglu, AS and Muderrisoglu, H. World Journal of Diabetes. 2015.
Briefly: Cardiac autonomic neuropathy (CAN) is the most clinically significant, and most frequently overlooked, diabetic autonomic neuropathy. CAN is caused by damage to the mostly parasympathetic nerve fibers that innervate the heart and blood vessels. CAN is associated with higher incidence of adverse cardiovascular events because of its relationship to silent myocardial ischemia, arrhythmias, intraoperative CV instability, cardiomyopathy and orthostatic hypotension. The earliest and even subclinical finding of CAN is a decrease in heart rate variability. The paper recommends testing diabetic patients for CAN because early therapy can delay, halt or reverse the progression of the disease.
Prediction of sudden cardiac death by fractal analysis of heart rate variability in elderly subjectsMakkallio, TH, et al. Journal of the American College of Cardiology. 2001.
Briefly: Alterations in HRV indicate the increased risk of cardiac mortality in elderly patients, and of sudden cardiac death in particular.
Heart rate variability and progression of coronary atherosclerosis Huikuri, HV, et al. Arteriosclerosis, Thrombosis and Vascular Biology. 1999.
Briefly: Lower heart rate variability is an independent predictor of rapid progression of coronary artery disease, and provides clinical information beyond traditional risk markers such as blood pressure and blood lipid levels.
Aortic pulse wave velocity improves cardiovascular event prediction: an individual participant meta-analysis of prospective observational data from 17,635 subjects Ben-Schlomo, Y. et al. Journal of American College of Cardiology. 2014.
Briefly: The addition of pulse wave velocity scores improved identification of high-cardiovascular risk populations who could benefit from more aggressive risk factor management.
Expert consensus document on arterial stiffness: methodological issues and clinical applicationsLaurent, S., et al. European Heart Journal. 2006.
Briefly: PWV is "generally accepted as the simplest, non-invasive, robust and reproducible method to determine arterial stiffness." Arterial stiffness and wave reflection are the most important determinants of increasing blood pressure and therefore are major contributors to risk of stroke and heart attack. "Aortic stiffness has independent predictive value for all-cause and CV mortalities, fatal and non-fatal coronary events and fatal strokes" and is now well-accepted as an intermediate endpoint for adverse cardiovascular events.
Effects of exercise modalities on arterial stiffness and wave reflection: a systemic review and meta-analysis of randomized controlled trialsAshor, AW, et al. PLOS ONE. 2014
Briefly: Aerobic exercise significantly improved arterial stiffness. Greater intensity of aerobic exercise and greater baselines stiffness associated with enhanced effects.
Small fiber neuropathy: a common and important clinical disorderHoitsma, E. et al. Journal of Neurological Sciences. 2004.
Briefly: Small fiber neuropathy is a relatively common disorder that may result in severe symptoms that are difficult to control. Standard electrophysiological tests are normal in SFN but other diagnostic tests, including Sympathetic Skin Response, which is a well-tested, simple and requires only a very modest amount of time, can detect abnormalities.
Sympathetic skin response: review of the method and its clinical use Kucera P, et al. Bratisl Lek Listy. 2004; 105(3): 108-16
Briefly: This paper provides an introduction to SSR as a method for assessing the function of the sympathetic nervous system, in particular by evaluating the postganglionic unmyelinated C-type nerves that innervate the sweat glands.