Early heparinization decreases the incidence of left atrial thrombi detected by intracardiac echocardiography during radiofrequency ablation for atrial fibrillation

Introduction: We reviewed our experience in managing intracardiac ultrasound-detected left atrial thrombus and analyzed the impact of the timing of heparin therapy on thrombus incidence. Methods and Results: We identified 508 patients undergoing ablation procedures for atrial fibrillation in which intracardiac ultrasound was used. All patients received unfractionated heparin during the procedure: 31 patients before the first transseptal puncture (preTS1), 257 between the first and second transseptal punctures (TS1-TS2), and 220 following both punctures (postTS2). By using intracardiac echocardiography (ICE), thrombus was detected in 30 of these 508 patients (5.9%). Of these, 29 were in the left atrium and constituted our study group. In 21 patients, the thrombi were successfully aspirated from the left atrium using strong suction through the transseptal sheath. All patients in whom thrombi were aspirated did well without neurological event or death. When patients received heparin therapy either preTS1 or TS1-TS2, there was a significant decrease in the occurrence of ICE-detected left atrial thrombus compared with those who received heparin postTS2 (0 of 31 patients (0%) preTS, 9 of 257 (3.5%) TS1-TS2, and 20 of 220 (9.1%) postTS2; (preTS1 vs postTS2, p=0.01; preTS2 [preTS1 and TS1-TS2] vs postTS2, p<0.001). Conclusion: Early administration of intravenous heparin, specifically before transseptal puncture, decreases the incidence of left atrial thrombi.