Chronic atrial fibrillation in patients with rheumatic heart disease: mapping and radiofrequency ablation of flutter circuits seen at initiation after cardioversion.

BACKGROUND There is little information concerning mapping and radiofrequency ablation (RFA) of arrhythmias seen during reinduction of atrial fibrillation (AF) after pharmacological and/or electrical cardioversion in patients with chronic AF and rheumatic heart disease. METHODS AND RESULTS Seventeen patients with rheumatic heart disease and symptomatic chronic AF underwent multisite atrial mapping during reinduction of AF after cardioversion. An organized atrial arrhythmia of varying duration was seen to precede the AF in all patients. The earliest atrial activity during this organized rhythm was near the coronary sinus ostium (CS OS) in 14 patients and along the left side of the interatrial septum (IAS) in 3 patients. RFA was performed in 16 patients (14 near the CS OS and 2 along the IAS). Postablation AF was inducible in 1 patient in whom RFA was preformed near the CS OS and in both patients when it was performed along the IAS. At a follow-up of 6 to 56 weeks (mean, 32 weeks), 10 of the 13 patients who had successful ablation were in sinus rhythm. All patients in whom AF was reinducible immediately after RFA continue to be in AF. CONCLUSIONS Induced AF in patients with rheumatic heart disease begins as a rapid organized arrhythmia with earliest atrial activity near the CS OS in most patients. RFA targeting the region of the CS OS is successful in suppressing the arrhythmia immediately in most of the patients and in most on follow-up.