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Show SCHOOL OF MEDICINE AND HEALTH SCIENCES UNDERGRADUATE RESEARCH ABSTRACTS SIGNIFICANCE OF PULMONARY VEIN ANTRAL REGION IN ATRIAL FIBRILLATION PATIENTS: A MRI APPROACH Brian Zenger, Matthias Koopmann, Nathan S. Burgon, (Rob S. MacLeod) Department of Bioengineering, Comprehensive Arrhythmia Research and Management Center University of Utah Atrial Fibrillation (AF) is the most c o m m o n heart arrhythmia affecting an estimated 2.7 million people in the United States with treatment costs projected at 6.7 billion dollars per year. The Comprehensive Arrhythmia Research and Management (CARMA) center at the University of Utah has implemented novel segmentation techniques using late-gadolinium enhancement MRI to quantify structural remodeling in the left atrial wall of the heart. Using previously validated image analysis methods and CARMA's Corview segmentation software; a percentage of remodeled tissue is calculated and used to classify each AF patient into the Utah Classification System. It still is not known if specific regions of the left atrium contribute more heavily to the severity of AF and the chance of successful ablation treatment. The goal of this project was to analyze the significance of the greatly debated pulmonary vein (PV) antral region of the left atrial wall and discover its potential importance in AF.The hypothesis was that structural remodeling in the wall of the PV antral region does not contribute to the predictive power of the Utah Classification System. To test this idea, w e reprocessed 97 patient scans to modify the initial three-dimensional segmentation of each left atrium using two protocols: 1) remove all structural remodeling from the PV antral wall; and 2) remove all parts of the PV antral wall. After reprocessing across all AF types; applying protocol one, 8 6 % of the patients remained in their original class [77-92%, 95%CI] and with protocol two 9 6 % of patients remained in the original class [90-99%, 95%CI]. These results confirm our hypothesis that this PV antral wall region does not play a statistically significant role in categorizing patients with the Utah Classification System nor impacts their predictive chance of successful treatment. In conclusion, these results support a simplification in the segmentation strategy used to classify patients and removes the need to identify this region of considerable patient-to-patient variation. Moreover, it suggests that structural remodeling in the wall of the PV antral wall region m a y play only a minor differentiating role in stratifying AF patients. References: CDC. "Atrial Fibrillation Fact Sheet." Center for Disease Control. Department of Health, 01 Feb 2010. Web. 17 Feb 2013. Rob S. MacLeod 137 |
