Pathological Turbulence of the Heart Rhythm and Activation of the Antinociceptive System as Predictors of the Complicated Course of Silent Myocardial Ischemia in Patients with Post Infarction Cardiosclerosis According to the Data of Long-term Observation
Authors: Merhel Tetyana , Sarapuk Ihor , Yusypchuk Ulyana , Vatseba Maryana , Haliuk Nadiya , Sarapuk Oksana , Komissarova Olha 
Published: July 2024

To date, the issues of evaluating the course of silent myocardial ischemia (SMI) after a myocardial infarction (MI) taking into account risk factors (RF), evaluating the pathological turbulence of the heart rhythm, the state of activation of the body’s antinociceptive system, which necessitates an in-depth study of this pathology, remain unresolved, as well as new differentiated approaches to the treatment and rehabilitation of the modern category of patients.
The objective: to analyze the features of the SMI course in patients with post-infarction cardiosclerosis depending on the RF. Identification of the interdependence between the degree of activation of the sympathoadrenal system and the features of the SMI course in patients with post-infarction cardiosclerosis, as well as the prognostic value for assessing the severity of the course of the disease.
Materials and methods. The research was performed on the basis of the Ivano-Frankivsk Regional Clinical Cardiology Center (Ukraine). 154 patients with a silent form of coronary artery disease, which occurred in people with post-infarction cardiosclerosis, were examined. The diagnostic criteria were: episodes of SMI verified with the help of HM ECG and a test with dosed physical load.
Results. Significant deviation of the ST segment which was detected during Holter monitoring of the ECG (HM ECG) in patients with SMI episodes does not mean that the absence of pain sensations in the presence of efferent nociceptive stimulation is a sign of the absence of ischemia and does not indicate an easier course of SMI compared to clinically manifest forms of CHD.
The average concentration of β-endorphins in patients with lipid metabolism disorders was 4.01±0.02 ng/ml, in the presence of diabetes mellitus this indicator was equal to 4.68±0.03 ng/ml (р<0.01), and in persons with concomitant arterial hypertension it was 4.91±0.02 ng/ml (р<0.05). In subjects with two or more RFs, the similar indicator was the highest and amounted to 5.73±0.03 ng/ml (р<0.01). The point-biserial correlation coefficient was equal to 0.61 (р<0.05), which indicates a sufficiently high probability of the influence of the processes of activation of the antinociceptive system on the risk of myocardial infarction and unstable angina.
Conclusions. It has been proven that the presence of postinfarction cardiosclerosis, type 2 diabetes mellitus, dyslipidemia, and arterial hypertension should be considered as factors that increase the risk of complications of coronary artery disease in patients with SMI. In the painless form of CHD, there is a probable increase in β-endorphins in the blood, which indicates the presence of pronounced afferent nociceptive stimulation, the intensity of which depends on the degree of myocardial ischemia. It has been proven that an increase of β-endorphins levels is associated with an increase in the risk of a complicated course of coronary heart disease in patients with silent myocardial ischemia.
The presence in patients with SMI of myocardial ischemia, pathological turbulence of the heart rhythm, and activation of the antinociceptive system are extremely important for understanding the main links of the course of SMI and make it possible to base the approach to the therapy of such patients on a differentiated system algorithm that takes into account the discrepancy between the clinical manifestations of the disease and its real impact on coronary perfusion and the condition of the vascular wall.