Frequency of arrhythmia in cardiovascular diseases

It is customary to speak of the 21st century as a century of future epidemics: epidemics of chronic heart failure, arterial hypertension (AH), type II diabetes mellitus (DM), obesity, atrial fibrillation (AF). However, the number of people on our planet is limited, therefore, the likelihood that the same people can be involved in different "epidemics" is quite high [1].

Cardiac arrhythmias are an important medical and social problem of modern medicine. Various aspects of heart rhythm disorders - clinical, electrophysiological, molecular-genetic, laboratory-immunological, hormonemetabolic are intensively studied in all countries of the world. Currently, the prevalence of heart rhythm disorders is recognized, their negative impact on the course of IHD, myocardial infarction (MI). Cardiac arrhythmias are considered an independent predictor of MI, various thromboembolic complications, and sudden cardiac death. heart rhythm disorders are a frequent complication of acute cardiovascular disease (CVD), which significantly worsens the course of the underlying pathology and, naturally, has a negative impact on the state of working capacity, up to the disability of patients [2].

Among all the heart rhythm disturbances that occur, AF is a leading position and can occur at any age, but more often in elderly patients. It is detected in 0,4% in the general population, in 2-5% of hospital patients, and among persons older than 65 years in 6.2% of cases in men and 4.8% in women. In some cases, AF occurs as a complication of IHD, AH, diabetes, thyrotoxicosis, mitral malformations. At the same time, there is an increase in the number of patients with this pathology and an increase in the registration of AF cases as a whole. This arrhythmia accounts for up to 40% of all cardiac arrhythmias. It is recognized as an important risk factor for the development of a feasibility study, leading to an increase in cases of temporary and persistent disability [3].

Paroxysmal, persistent and persistent forms of AF require an individual approach to control this arrhythmia. There are many hypotheses for the mechanisms of the development of phase transitions, but the most widespread is the theory of focal mechanisms and the hypothesis of multiple fine waves. And these mechanisms can be combined with each other. Focal mechanisms include trigger activity and excitation circulation by microreentry type. According to this theory, AF occurs as a result of the arrival of multiple pulses from autonomous foci, which are most often located in the mouths of the pulmonary veins or along the posterior wall of the left atrium near the connection with the pulmonary vein. Fabrics in these zones have a shorter refractory period, which approximates their properties to the cells of the sinus node. According to the hypothesis of multiple shallow waves, the phase transition is conserved as a result of a chaotic conduct of many independent small waves. Changes in the atria also occur after the development of AF. This shortens the refractory period of the atrium by suppressing the current of calcium ions through L-type channels and increasing the intake of potassium ions into the cells. Also reduces atrial contractile function due to a slowing of the intake of calcium ions in the cells, the violation of the release of calcium ions from the intracellular depot and the violation of energy metabolism in myofibrils. Slowed blood flow in the atria due to a violation of their contraction, which leads to the formation of thrombi mainly in the left atrial appendage [4,5,6].

The overwhelming majority of studies on epidemiology of AF have been conducted in Europe and North America. Symptoms of AF have been studied in many studies, in particular The French Etudeen Activité Libérale dela Fibrillation The Auriculaire study reports that in patients with paroxysmal AF, the symptoms manifest themselves more often than in persistent and permanent forms [7]. But despite this, studies conducted by Colombia and Canada found that between 15% and 30% of cases of AF is asymptomatic [8,9], and Euro Heart Surveyon Atrial Fibrillation gives tax results [10].

A study was conducted at the University of Minnesota, consisting of a large cohort of 185566 patients from three major studies: the Atherosclerosis Risk in Communities study, the Cardiovascular Health Study and the Framingham Heart Study. In this work, the duration of 5 years, there are risk factors for the development of AF. According to this study, elderly age, European origin, high growth and body weight, left ventricular hypertrophy, dilatation of the left atrium, diabetes, AH, IHD, are risk factors for AF development [11].

Thus, heart rhythm disturbances represent a serious problem of modern medicine, which requires further research in this area.