Mapping the Characteristics of Atrial Activation Patterns During Atrial Fibrillation

Atrial fibrillation (AF) is the most common tachyarrhythmia in the Western world. In our laboratory, mechanisms of AF have been characterized using simultaneous multisite mapping (512 recording sites) in the canine sterile pericarditis model and in AF patients. Studies of AF in the canine sterile pericarditis model have demonstrated that AF is due to one or more driver sites firing rapidly causing fibrillatory conduction. The ability to reliably identify such driver areas in real time would be invaluable for identifying targets for ablation. Moreover, mechanisms of AF in the vagal nerve stimulation (VNS) model and patients with spontaneous AF after open heart surgery (OHS) are still unclear.In the present studies, the driver region, which is either reentrant or focal, was further characterized by cycle length variation (CLV) using simultaneous multisite mapping. To determine the location of each driver, CLV maps generated using a CLV detection (CLVD) analysis were able to classify reentrant and focal drivers using the optimal CLV percentage cutoffs to map their location on an anatomical atrial template. Furthermore, in the OHS patients, the CLVs were measured from atrial electrograms (AEGs) recorded from temporary wire electrodes sutured to the right atrium (RA), the left side of Bachmann’s bundle and posterior left atrium. During AF, a regular rhythm was recorded during four of six episodes from the left atrium, while an irregular rhythm with varying AEG morphologies and CLs was present in the RA. In two episodes, no area of regularity was seen.Another study was conducted to investigate the mechanism of AF in the VNS canine model. Activation sequence analysis was performed on recorded AEGs during AF. In this VNS model, AF was due to multiple foci firing at rapid, but different rates producing and maintaining AF. Atrial activation was characterized largely by collision of wave fronts from the foci at continuously variable sites. There was also fusion of wave fronts. Reentry was rarely seen.The work demonstrated in this dissertation significantly advances our understanding of atrial activation patterns and mechanisms of AF. It also provides new methods to help identify targets quickly and precisely for ablation.

Name thesis:degree_name

Doctor of Philosophy

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Biomedical Engineering

Grantor dc:publisher

Case Western Reserve University School of Graduate Studies

Year dc:date

2013

Author dc:creator

• Lee, Seungyup

Contributors dc:contributor

• Durand, Dominique
• Waldo, Albert

• Biomedical Engineering

Statement dc:rights

• unrestricted
• This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.

Language dc:language

English

Repository record dc:identifier

http://rave.ohiolink.edu/etdc/view?acc_num=case1354634723

OAI identifier oai:identifier

oai:etd.ohiolink.edu:case1354634723