Table 3.

Summary table of cardiovascular reflex tests and spectral analysis of HRV

Protocol, year (reference)	Test	Position	Approximate time for test (mins)	Apparatus used	Outcome measure
The Ewing protocol 1982 [165]	(Following order downwards) HR response to Valsalva manoeuvre	Sitting	5	Aneroid manometer	Ratios of change in R–R intervals at two fixed points for each of the HR stimuli reflecting PNS component of ANS BP tests denote tests reflecting SNS component of ANS BP change by minimum amount not exceeding a maximum drop on standing
	HR variation to deep breathing	Sitting	2	ECG
	BP response to sustained handgrip	Sitting	5	Handgrip dynamometer, sphygmomanometer
	Immediate HR response to standing	Lying to standing	3	ECG
	BP response to standing	Lying to standing	(Same 3 min)	Sphygmomanometer
The O’Brien protocol 1986 [98]	HR during resting (baseline resting HR variation)	Lying	1	ECG	Normal age-adjusted ranges for the R–R ratios calculated from changes in HR (nearest five yearly age group in a table)
	HR with deep inspiration	Sitting	(10-s single deep breath)	ECG
	HR with the Valsalva manoeuvre	Lying	1	ECG
	Immediate HR response to standing	Standing	1	ECG
Spectral analysis of HRV (Agelink et al.) 2001 [23]	VLF (SNS component of ANS) 0.003 to 0.04 Hz LF (PNS and SNS component of ANS) 0.04 to 0.15 Hz HF (PNS component of ANS) 0.15 to 0.4 Hz	Lying	10	ECG	Spectral analysis computer software during a resting ECG, age- and gender-dependent normal values of each of the HRV indices

ANS autonomic nervous system, BP blood pressure, ECG electrocardiogram, HF high frequency, HR heart rate, HRV heart rate variation, LF low frequency, PNS parasympathetic nervous system, SNS sympathetic nervous system, VLF very low frequency