PO-03-098 DIFFERENTIAL PACING FOR IDENTIFYING MULTIPLE INTERATRIAL CONNECTIONS

Interatrial connection (IAC) is reported to be an anatomical structure associated with complex biatrial tachycardias. However, electrophysiological conduction between left atrium (LA) and right (RA) has not been fully investigated. This study was distinguish multiple IACs by using different pacing sites. Twenty patients paroxysmal atrial fibrillation who underwent ablation were enrolled. High-density mapping of before created during continuous from sinus node (SN) or low lateral RA (LL-RA), LA appendage (LAA) posterior wall (LA-PW), respectively. Focal activation sites defined as IAC breakthrough segments each recorded. The average number total 4.9±1.3 4.1±1.2 for RA-LA LA-RA, respectively (Figure A1,2). There no significant difference in directional connections (cranial pacing, p=0.35; caudal p=0.62) B). Connections at the level interatrial septum (IAS) Bachmann’s bundle mostly found connections, however more than one third had pulmonary veins, its carina, roof coronary musculature. LA-RA mainly existed IAS, superior inferior vena cava also frequently related. Only either single site SN LL-RA elucidated significantly smaller compared (SN vs total, 3.2±0.8 4.9±1.3, p<0.001; 3.2±1.5 p<0.001) C1). Similarly, only LAA LA-PW revealed (LAA 3.0±0.8 4.1±1.2, C2). Although did influence interarial conductions (RA-LA, p=0.09; p=0.85), cranial preferentially disclosed upper lower septal segments, (upper RA-LA, LL-RA, 73.4% 46.9%, p=0.0037; 66.1% 41.0%, p=0.013) D1,2). Pacing locations may required order reveal entire connections.