Heart rate variability: for real doctors. Translation from the Russian version of the book, published at Kharkiv, 2010, 131 p.
The basics and practice of the clinical use of the technology of heart rate variability are outlined for doctors of all specialties and students of medical faculties of universities.
Protocol example: active orthostatic test
A case can be used as a sample for compiling and as a model for drawing up any other protocol. It can be a short recording protocol, it can also be included in a long recording as one of its stages (one of the protocols included in it).
• determining the degree of the physiology of orthostatic reactions;
• identification of early violations of the baroreflex control of arterial
• establishment of the genesis of syncopal states;
• determination of contraindications for prescribing drugs that violate
baroreflex control of blood pressure;
• monitoring the condition of patients taking drugs that affect the baroreflex control of blood pressure;
• establishing the degree of neuropathy (diabetic, other);
• confirmation of the diagnosis of orthostatic hypotension in old;
• setting the degree of risk of sudden coronary death in cardiac patients and making decisions on its prevention;
• evaluation of the effectiveness of medical interventions;
• optimization of therapeutic interventions;
• control and optimization of any quality control measures health
• ECG registration at all stages of the protocol or continuous with marks of the beginning and end of each of the stages,
• being examined in the supine position according to the standard protocol for 7 minutes,
• active transition to the standing position and being in this position without support for the hands during the entire transition period and no less than 7 minutes after an established ECG rhythmogram, characteristic of the standing position,
• registration of arterial pressure at stages:
– in the 7th minute of lying down,
– a minute after the ECG rhythmogram has taken an established form
after moving to a standing position
– in the 7th-minute standing position,
• processing of the ECG rhythmogram for the selected well-established 5-minute
areas for lying and standing, • analysis and interpretation of results.
• duration of the transition process up to 3 minutes,
• increase in heart rate by (3-5)%,
• drop in the total power of the HRV spectrum by (35-50)%,
• a relative increase in the power of the LF component,
• a corresponding decrease in the power of the HF component,
• growth in the LF / HF ratio.
Interpretation of results:
• the absence of the expected increase in the LF / HF ratio with a history of syncopal conditions may indicate their vaso-vagal genesis,
• an insufficient increase in LF / HF during the test requires a careful attitude to the prescription of drugs that alter the baroreflex control of arterial pressure,
• lack of reactions to orthostasis in patients with diabetes mellitus indicates late stages of diabetic neuropathy,
• inversion of orthostatic responses is characteristic for some cases of orthostatic hypotension of the elderly,
• a sharp decrease in the total power of the spectrum in a standing position indicates a high risk of life-threatening conditions.
The value of the protocol increases significantly when other samples are included (when it is added) (a multi-step protocol).
How do we understand the active orthostatic test (active tilt test):
• transition to a standing position is associated with activation and being in it – with overshooting of baroreceptor control.
• really great importance belongs to unexplored navigation systems (retention of equilibrium position)
• the quality of the transition to the standing position is determined by the quality of the rapid regulation
• the quality of standing up is determined by the quality of slow and very slow regulation
• In fact, an active orthostatic test is the result and reflects a holistic change in the regulation system.