Association of atrial fibrillation and atrial flutter with sick sinus syndrome: a review of the issue based on examples of clinical observations

Despite significant progress in the treatment of patients with cardiac arrhythmias, atrial fibrillation (AF) remains one of the leading causes of serious cardiovascular events around the world. Currently, radiofrequency ablation (RFA) is the first-line method in the treatment of patients with AF. However, signs of sick sinus syndrome (SSS) are found in some AF patients after RFA, which requires urgent or planned pacemaker implantation. Aim. To review current therapies for AF and sick sinus syndrome (SSS) and analyze peculiarities of the SSS development after RFA for AF. Materials and methods. The analysis of the world literature data was carried out along with the analysis of our own clinical observations of patients with AF who underwent RFA. Results. As a result of the data analysis, it was proposed to identify three possible groups of causes why AF patients may develop SSS after RFA: 1) organic (associated with degenerative fibrosis of the sinus node tissue that occurs during aging, or with other underlying organic changes in the sinus node), 2) functional (associated with the remodeling of the sinus node tissue and the surrounding tissue of the atrial myocardium caused by prolonged AF persistence), 3) iatrogenic (associated with the effects of antiarrhythmic drugs on the sinus node or caused by the RFA itself). Each group of causes identified was illustrated by a clinical case with the following analysis of long-term results of RFA. Conclusions. It was proposed to develop a scale for SSS prediction in patients after RFA for AF evaluating a patient’s medical history, resting electrocardiography, 24-hour electrocardiographic monitoring, and, in some cases, coronary angiography to assess the peculiarities of the sinus node blood supply. The use of the above predictors could reduce the percentage of possible complications such as development of SSS in patients after RFA and also help to identify patients who may need a pacemaker implantation in the future.