Mapping and Ablation of Premature Atrial Contractions Originating from the Posterior Mitral Annulus: A Case Report

Premature Atrial Contractions (PAC) is frequent arrhythmias. Previously, regarded as a benign electrocardiographic finding, they are now linked to adverse outcomes such as, stroke and all-cause mortality. Furthermore, a high burden of PACs >1.500/24 hours has a predicted probability of atrial fibrillation occurrence. Herein, the authors presented a case of a 35-year-old male patient, with high burden PACs, originating in the posterior mitral annulus. Treatment with class IC (flecainide, propafenone) antiarrhythmic drugs and beta blockers (bisoprolol) was ineffective in controlling the tachycardia, therefore, catheter ablation was performed. The procedure was performed using the Three-Dimensional (3D) Biosense Webster Carto 3 electroanatomical mapping system. The area of the earliest atrial signal was located at the posterior mitral annulus. Successful elimination of the ectopy was obtained with Radiofrequency (RF) application on the posterior mitral ring. A single RF application of 30 W for 60 seconds abolished PACs, with no further recurrence. Holter Electrocardiogram (ECG) showed, no PACs at one, six and 12 months follow-up. Catheter ablation remains an effective approach to cure the arrhythmia, when medical treatment with antiarrhythmic drugs is ineffective or undesirable in patients with high burden PACs.