Idiopathic Form of Atrial Fibrillation, Inflammation and Clinical Results of Radiofrequency Ablation

Aim. To evaluate the impact of inflammation on clinical results of radiofrequency ablation (RFA) for atrial fibrillation (AF). Material and methods. Totally 274 patients studied, admitted to the hospital with the diagnosis idiopathic AF, of those just 67 (24,5%) had this diagnosis been confirmed at previous stage of clinical assessment. All patients underwent intracardiac investigation and RFA AF, endomyocardial byopsy (EMB) with histologic and immunohistochemical studies for immunophenotype cells study of the endomyocardial infiltrate and revealing of cardiotropic viruses antigenes expression: to parvovirus B19, enterovirus, virus human herpes 1 and 2 types, adenovirus, cytomegalovirus, Epstein-Barr virus. We studied efficacy of catheter treatment, development of early and late recurrent episodes of atrial tachiarrhythmias. Results . Histologic changes in right ventricle myocardium were not found in 9 (13,4%) patients. In 26 (38,8%) we found fibrous changes of myocardium: in 11 (42,3%) — mostly perivascular fibrosis, in 8 (30,8%) — small-nodular, in 7 —(26,9%) — perimuscular. Inflammatory changes (according to Dallas criteria) were marked in 32 (47,8%) patients, of those in 9 (28,1%) lymphocyte infiltration found (less than 14 lymphocytes mm ). In one of these patients (3,1%) there was combination of herpes sumplex virus 2nd type and Epstein-Barr. In 23 patients (34,3%), myocarditis found, of those in 18 (78,3%) virus expression found. In one (5,6%) patient there was expression of 3 viruses, and in six (33,3%) patients — of two viruses, in 11 patients (61,1%) — one virus antigen. Total follow-up lasted for 19,3±3,7 months. Effectiveness of primary RFA in patients with intact myocardium was 88,9%, with fibrous changes — 46,2%, in myocarditis — 34,4%. Early recurrent episodes of arrhythmia were absent in unchanged myocardium (53,8%) and rarer — late (34,6%). Having inflammatory changes led to reverse relation, and later recurrent episodes developed more frequently (53,1%) and rarer — early (37,5%). Conclusion. By our data, only 24,5% patients do not have diseases that predispose to arrhythmias. Histologic study showed that only 10% patients have idiopathic type of arrhythmia, and a half have subclinic inflammatory changes of myocardium, the rest have fibrous changes. Presence of inflammatory and fibrous changes in myocardium increases the quantity of early and late arrhythmia onsets and, therefore, double decreases RFA AF efficacy.