Usefulness of simultaneous isolation of the coronary sinus and the left atrial inferior wall for persistent atrial fibrillation refractory to box isolation

Abstract Funding Acknowledgements Type of funding sources: None. Background In patients who are refractory to box isolation (BoxI) and have atrial fibrillation (AF) substrate in left inferior wall (LAIW), LAIW is effective, but the procedure highly difficult because connection between coronary sinus (CS) dense. this study, we report four cases persistent AF which simultaneous CS was so effective. Methods Results Case 1 a 76-year-old female with had undergone BoxI failed mitral isthmus block (MIB) creation. However, tachycardia (AT) persisted. 4th session, chemical ablation Marshall vein performed, AF/AT terminated, MIB created. Thereafter, multiple ATs were still inducible by rapid pacing. Because AT seemed be confined LAIW, attempted isolate performing linear right pulmonary (RIPV) posteroseptal annulus (MA) near ostium, parallel along posterior MA. could not achieved. Finally, ostial from atrium (RA) succeeded CS. burst pacing induce although RA maintained rhythm (SR). Rapid AT/AF. 2 78-year-old completed Raid induced AF. cycle length apparently shorter than RA, LAIW. Firstly, performed RIPV ostium During ablation, converted AT, finally returned SR while sustained within This reentrant circling After isolated during SR. isolation. 3 74-year-old BoxI. Although non-pulmonary (non-PV) trigger documented precise origin non-PV identified due infrequency. 4 64-year-old male He catheter three times. Fractionation map showed that likely located Therefore, 4. We MI MA, both cases. has never recurred 2. antiarrhythmics Conclusions BoxI, if or triggers, may new therapeutic strategy. Simultaneous requires at CSos RA.