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.
8. Regulation in human health
Heart rate and TP of HRV
Both indicators are interrelated: the higher the HR, the lower TP of the HRV, and vice versa.
Regarding this book, it is natural to dwell on the TP, but in real life, HR is more accessible, and therefore we will stay on it.
The topic is important, but physicians do not pay attention to it.
We consider it not possible, but necessary to pay special attention to HR.
HR is one of the fundamental physiological characteristics of a person, not of the heart only. It determines by gender, body composition, age, metabolism, functional type, physiological state (rest, load, their types), and other factors. It changes in pathological conditions.
Moreover, if it changes by the “favorable” development of the pathological state, then everything is fine. If not – trouble. That is why HR today refers to independent predictors of health, illness and even death.
There are genetic grounds for being HR independent factor in the quality of health and a predictor of fatal conditions at the same time.
In rats with spontaneous arterial hypertension, the genetic locus of chromosome 3 (HR-SPI) is directly involved in the regulation of HR and does not affect blood pressure (BP). Similar genetic loci are present in human chromosomes.
HR is genetically encoded by loci specifically designed for it.
Resting HR is a predictor of death.
The higher the resting HR, the higher the risk of death:
• with a resting HR of 90-99 beats/min versus 60 beats/min, the risk of death, regardless of its cause, is three times higher,
• in persons older than 81 years, the risk of recurrent coronary episodes is increased by 14%,
• at resting HR more than 84 beats/min with its growth for every 5 beats/min, and with more than 100 beats/min – increases by more than 40%,
• in patients with coronary heart disease (CHD), resting HR above 90 beats/min is an independent predictor of sudden death, and its frequency compared to that in patients with ischemic heart disease with a heart rate of 60 beats/min increases 5 times or more,
• an increase in resting HR to 90-100 beats/min in the first 2 hours in the cardio-resuscitation and intensive care unit is associated with a doubling of mortality from AMI, and more than 100 beats/min – trebling, in patients with AMI with a resting HR of more than 90 beats/min 4-6 times higher than that of 90 or 84?
Physiological for resting conditions, many consider the HR range from 60 to 100 beats/min. Kossman and Jose installed it in experiments with pharmacological blockade of the sinus node with atropine and propranolol. These borders have not been revised for many years and have not been adjusted.
In the Framingham study completed in 1987 on a population of 5,000 people (their borders) specified HR: 46-93 beats/min for men and 51-95 beats/min for women with an average level of 70 beats /min.
Later, Spodic proposed to narrow them to 50-90 beats/min with taking 90 beats/min as the lower threshold of sinus tachycardia. The reason for the proposal was the establishment of a negative predictive value of the heart rate more than 90 beats/min.
More stringent restrictions on the upper limit of physiological resting HR follow from Wilhelmsen et al. Data, which showed a sharp increase in the risk of fatal states after exceeding the threshold of 84 beats/min.
The proverb “Hurry slowly” – into the “apple” for the upper limit of the resting HR. It does not matter if we are talking about a healthy or sick person.
More HR – less TP of HRV, and vice versa. The patient is 51 years old. At the top – above the HR and below the TP of the HRV. At the bottom – vice versa.