Risk factors for the development of pacemaker dysfunction

Rationale: The only effective method of treating life-threatening bradyarrhythmias is the implantation of a permanent pacemaker. There are isolated prospective studies in the literature on permanent pacemaker dysfunctions that have shown significantly worse clinical outcomes, but there is currently very little retrospective data on permanent pacemaker dysfunctions. Objective: To analyze the frequency and risk factors for the development of permanent pacemaker dysfunction. Methods: The medical histories and outpatient records of 948 patients with various forms of bradiarrhythmias operated in the clinic from 2006 to 2021 were retrospectively studied in order to identify dysfunction of the PM system that occurred both in the early and late postoperative period. All patients were operated in one center. The clinical and demographic indicators of patients, morphofunctional parameters of the heart according to transthoracic echocardiography, chest X-ray and Holter ECG monitoring data, as well as pacing parameters were analyzed. By the method of factor analysis, the most frequent types of dysfunctions were identified, the causes of their development were studied, as well as the relationship with concomitant diseases and programming of stimulation parameters. Results: As a result of a retrospective study, among 78 patients with identified dysfunction of the PM system, 7 (9%) patients registered premature depletion of the PM power supply, 5 (6.4%) patients - PM syndrome, another 24 (30.8%) patients - dislocation of the endocardial electrode. In 20 (25.6%) patients, an increase in the stimulation threshold was registered, in 8 (10.3%) patients a sensitivity disorder, as well as in 4 (5.1%) patients, a decrease in the impedance of the endocardial electrode was noted, and in 10 (12.8%) patients - an increase in the impedance. During the factor analysis, it was revealed that most often the enlarged right chambers of the heart are associated with dysfunctions against the background of valvular defects and dilated cardiomyopathy, myocardial remodeling against the background of chemotherapy and radiation therapy, post-infarction cardiosclerosis in the implantation area of the electrode, as well as untimely and inadequate programming of the PM. In addition, an interesting finding was the relationship between the development of dysfunctions and an increase in the level of uric acid, urea and creatinine in the blood, prolonged and uncontrolled use of steroid drugs and bronchodilators. Conclusion: identification of the most common risk factors for dysfunctions of the pacemaker system through a comprehensive analysis of clinical, demographic and instrumental data, as well as the study of the mechanisms of their development, is necessary for a personalized approach to the treatment of patients with bradyarrhythmia, in order to prevent violations in the pacemaker system.