Assessment of echocardiographic indicators of electric train drivers who have been ill with a new coronavirus infection

Introduction. The pandemic of a new coronavirus infection has become an emergency of international importance due to the high risk of developing life-threatening conditions and complications. Long-term cardiovascular outcomes after COVID-19 remain poorly understood, especially among professional groups, including those related to transport management, which account for a large number of people. Employees of locomotive crews in the course of their professional activities work under the influence of various factors of the industrial environment (noise, vibration), occupational stress (shift work, violation of work and rest, monotony of work) and also non-productive factors: smoking, increased body weight, high blood pressure, which affect the development of cardiovascular diseases, and coronavirus infection can worsen cardiovascular complications. Currently, the use of echocardiography allows timely detection of structural and functional disorders of the heart, which helps both in the early and late postinfection period. The study aims to evaluate echocardiographic indicators in locomotive crew workers who had suffered a coronavirus infection, depending on the severity of the course and the presence of non–occupational risk factors for the development of cardiovascular diseases. Materials and methods. The study included 20 male employees of locomotive crews, aged 44.7±6.4 years, who suffered COVID-19 in the first and second quarters of 2022, and are currently continuing their work. The research was conducted in the period 2022–2023. Depending on the severity of the coronavirus infection and non-professional risk factors, the researchers divided the workers into 2 groups: the 1st group consisted of workers who had suffered a severe form of COVID-19 and had risk factors: smoking, increased body weight, high blood pressure; the 2nd group consisted of workers who had suffered a mild form of COVID-19 without non-occupational risk factors. Employees underwent echocardiography with Doppler examination, measurement of blood pressure and heart rate every three months, for a year, after the closure of the employee disability sheet. Archival studies of echocardiography, blood pressure and heart rate measurements performed before COVID-19 disease were taken from outpatient records. Results. Experts have identified in workers of group 1 (severe form), with existing non-occupational risk factors for the development of cardiovascular diseases (smoking, increased body weight, high blood pressure), in contrast to echocardiography indicators of group 2, signs of remodeling of the left ventricular myocardium, due to a slight increase in the linear size of the heart (thickness of the interventricular septa in the diastole, final diastolic size) with preserved systolic function of the left ventricle, ejection fraction of more than 60% (according to the Teicholz method), but with impaired relaxation of the left ventricular myocardium (E/A<1, DT>240 ms, IVRT>90 ms). When comparing systolic blood pressure and heart rate, the authors noted an increase in both groups. In workers who have suffered a severe form of coronavirus infection, blood pressure indicators correspond to "grade I hypertension" and require the appointment of antihypertensive therapy on an ongoing basis. In group 2 workers, blood pressure indicators correspond to "high normal blood pressure" and do not require the appointment of regular antihypertensive therapy. Limitation. The limitation of the study is the small number of observations of employees of locomotive crews currently working and who have had a coronavirus infection. Conclusion. Structural and functional changes in the heart of locomotive crew workers who have had coronavirus infection and are currently working are associated with the severity of COVID-19 and the presence of risk factors (high blood pressure, smoking, overweight). In the mild form of coronavirus infection in workers, the authors revealed functional changes – an increase in heart rate and blood pressure to the level of "high normal blood pressure", in the severe form functional (increased heart rate, blood pressure, impaired relaxation of the left ventricle) and structural (initial manifestations of left ventricular myocardial remodeling). Employees of both groups who have suffered both severe and mild forms of coronavirus infection are currently continuing their work as an "electric train driver" and currently need the supervision of therapeutic and diagnostic specialists. Ethics. This study was approved by the local Ethics Committee of the Izmerov Research Institute of Occupational Health (extract from Protocol No. 1 dated February 16, 2022).