Actuality. The problem of frequent treatment of older patients with age-related diseases for medical care has emerged in the system of medicine in Russia. The development of the frailty syndrome in older people is also increasing, which requires the development of programs to improve geriatric care. Older patients are heterogeneous in terms of the development and prevalence of pathologies. Purpose. To study the heterogeneity of the clinical course of the frailty syndrome. Materials and methods. The study evaluated the prevalence of heart rhythm disorders in patients of different ages. We were divided patients in next groups according to the age classification: middle-aged patients, n= 76 people; elderly patients, n= 87 people; senile patients, n= 86 people. The assessment of the level of chronic immune inflammation was performed by calculating the level of cytokines (IL-1 - alpha, IL-10) on the StatFax 2100 immunoassay analyzer. To assess the level of anti-radical actinicity, we used ABTS+ radical, which is metastable. The rection was monitored spectrophotometrically. Then the activity area was measured in %. The greater the area of activity, the greater the number of radicals in the body, which indicates a decrease in anti-radical activity. Results. Senile patients are characterized by the prevalence of the frailty syndrome in comparison with elderly patients, which is natural. According to the results of our research, it was noted that the frequency of heart rhythm disorders increases with age, which corresponds to general medical patterns. Older patients with heart rhythm disorders and the frailty syndrome had the most pronounced inflammatory background and the lowest antiradical activity in terms of heterogeneity of the frailty syndrome with predominance of motor disorders compared to older patients with heart rhythm disorders and the frailty syndrome with predominance of cognitive disorders or social problems. Conclusions. In the course of our study, we found strong positive correlations between the presence of the prefrailty/frailty syndrome and cardiac arrhythmias, such as atrial fibrillation (r=+0.88, p