Abstract 16000: Occurence of Cerebral Microembolic Signals During Pulmonary Vein Isolation: A Comparison of Two Different Ablation Techniques
Pulmonary vein isolation (PVI) techniques have been increasingly used to cure atrial fibrillation (AF). Recently, concerns have been raised that subclinical brain damage may occur due to microembolisation during these procedures. We compared the occurence of bubble formation seen on intracardiac echocardiography (ICE) and microembolic signals (MES) detected by transcranial Doppler (TCD) using different ablation techniques and anticoagulation strategies.
Methods: Consecutive patients undergoing PVI for paroxysmal or persistent AF were assigned to 3 different treatment groups: I:cryoballoon (CRYO) ablation and conventional intraprocedural anticoagulation regime with target ACT>250 sec; II: ablation using multipolar duty-cycled radiofrequency (RF) catheters (PVAC) and conventional intraprocedural anticoagulation regime with target ACT>250 sec; III:ablation with PVAC catheter using a more aggressive anticoagulation protocol with ACT>350 sec. Bubble formation (few, moderate, shower) was assessed on ICE and the number of MES was detected in both middle cerebral arteries using TCD with the ability to discriminate between solid and gaseous emboli.
Results: 26 procedures in 25 patients (age:51±13 years; female:male 5:20) were included in this prospective study: 7 procedures in Group I, 12 in group II and 7 in group III. There were no significant differences between groups regarding demographics, type of AF, CHADS2-score and left atrial size. Strong correlation (r = 0.89) was found between the degree of bubble formation and the number of MES in all groups. Further results are shown in Table I.
Conclusion: Bubble formation on ICE shows a strong correlation with the number of MES during ablation regardless of the ablation technique and anticoagulation protocol used. Duty-cycled RF ablation is associated with significantly more MES even when agressive anticoagulation is applied. Most of MES are gaseous in nature and occur during energy delivery.
- © 2011 by American Heart Association, Inc.