LD products analyze the photoplethysmography (PTG) waveform for precise and accurate detection of the beat to beat heart rate (RR-intervals).
The blood pressure lying down and while standing are measured by oscillometry (ANS-1) or by volume plethysmography (TM-FLOW)
The sudomotor function is assessed by a galvanic skin response device either using metal plates following an electrical stimulation of the sweat glands (ANS-1), or disposable cloth electrodes and pressure cuffs placed on the ankles following a double stimulation: 1) metaboreflex and 2) electrical stimulation of the sweat glands (TM-FLOW).
The LD products’ assessment of the autonomic nervous system (ANS) follows the diagnostic guidance of the Cardiac Autonomic Neuropathy (CAN) Subcommittee of the Toronto Consensus Panel on Diabetic Neuropathy.
The methods for assessing the autonomic nervous system in a clinical practice include the evaluation of symptoms and signs, as well as the Heart Rate variability (HRV) analysis, the Cardiac autonomic reflex tests (CART’s) which are based on heart rate and blood pressure recordings. In addition, Sudomotor function tests are performed.
The Gold standard assessment of CART’s includes heart rate variability analysis and Ewing tests - such as heart rate responses to deep breathing , standing, Valsalva maneuver and blood pressure response to standing. A tilt table may be suggested for performing the tests.
The CART’s score is calculated by using the Jermendy Scoring System and it allows the result interpretation according to the guidance of the neurological associations.
* Medications that significantly affect autonomic testing results:
Chlorpromazine, Thioridazine (Effects: Anticholinergic, antiadrenergic); Tricyclic antidepressants (Effect: Anticholinergic); Bupropion, Mirtazepine, Venlafaxine (Effect: NE reuptake inhibitors); Clonidine (Effect: Alpha-blocking agent); Alpha-blockers, Beta-blockers, Ca-channel blockers (Effects: Alter vasomotor tone and responses); Opiates (Effects: Intoxication: smooth muscle relaxation, histamine release, withdrawal hyperadrenergic state);
Topical capsaicin (Effect: Altered skin vasomotor responses).