Abstract 11167: Prevalent Locations of Left Atrial Scar in Patients with Non-Paroxysmal Atrial Fibrillation: A Single-Center Experience

Abstract

Introduction: Left atrial (LA) scar, identified by bipolar voltage mapping, is a frequent finding in patients with non-paroxysmal atrial fibrillation (NPAF). We evaluated the most common sites of scar formation in the LA in a series of NPAF patients. Methods: Consecutive NPAF patients undergoing their first catheter ablation at our center were included in this analysis. Voltage mapping was performed in sinus rhythm (SR) using a 3D electro-anatomic mapping system and a 10-pole circular mapping catheter. The LA was divided into following regions: septum, posterior wall, lateral wall, anterior wall and roof. The threshold for low voltage was <0.5 mV (with a color range setting 0.2-0.5 mV). Results: A total of 359 NPAF (224, 62.4% persistent AF) patients undergoing their first ablation procedure with voltage mapping performed in SR were included in this study. Mean number of points taken to map the scar was 281.2±96.3. Low voltage area was detected in 209/359 (58%) cases; 108 (48.62%) persistent AF, 101(74.8%) long-standing persistent AF, p<0.001). The scarring was observed to be located in the anterior septum in 98 (46.9%) and posterior wall of the LA in 136 (65%) patients (FIGURE) Conclusion: In the NPAF population, LA scar was detected in significantly less number of persistent AF patients. Scars were mostly located in the posterior wall of left atrium followed by the antero-septum region. Characterization of the LA scars would be helpful in optimizing the ablation targets.