Functional state of the cardiovascular system in adolescents and young men of military age with bradyarrhythmia

The article presents the results of clinical and instrumental examination of adolescents and young men of conscript age with sinus bradycardia. The study involved 2067 people (mean age19,7 ± 2,7 years), subject to conscription (from 17 to 27 years) and potential conscripts (16-year-olds). According to the results of the screening express of ECG diagnostics, all participants of the study were divided into groups – with normocardia (n = 1266), with tachycardia (n = 171) and with bradycardia (n = 630). The article shows that in patients with sinus bradycardia, the size of the left atrium (р < 0,05), pulmonary artery trunk (р < 0,05), right atrial (р < 0,05) and right ventricle (р < 0,05) more than in individuals with normosystole and tachysystole types of heart rhythm. In patients with bradysystole type of heart rhythm, lower values of the ejection fraction (р < 0,05) were recorded in comparison with other types of rhythm at higher shock volume of blood (р < 0,05), the end diastolic volume of the left ventricle (р < 0,05) and the end diastolic size of the left ventricle (р < 0,05). Patients with bradysystole type of heart rhythm were characterized by higher rates of inotropic (р < 0,01), chronotropic reserve (р < 0,05), duration of the recovery period (р < 0,01) with lower coronary reserve indices (р < 0,01) and maximum oxygen consumption (р < 0,05) compared with normosystole and tachysystole types of rhythm. In 63,7% of patients with sinus bradycardia, the Holter monitoring determined a decrease in the mean level of heart rate below the reference values. Sinus bradycardia is associated with rhythm and conduction disorders, as well as chronobiorythmological desynchronizes.