Abstract 16433: Advanced Atrial Tissue Fibrosis Quantified Using Late-Gadolinium Enhanced Cardiac MRI is Associated with Significant Ventricular Conduction Delay
Introduction: Late-gadolinium enhanced cardiac MRI (LGE-MRI) is used to quantify atrial tissue fibrosis. We studied the impact of atrial fibrosis in atrial fibrillation (AF) on ventricular tissue. We hypothesized that atrial fibrosis is associated with ventricular involvement manifested by QRS widening and conduction system disease (CSD).
Methods: 427 patients with AF were included. ECGs were analyzed for QRS duration and the presence of CSD including left bundle branch block (LBBB), right bundle branch block (RBBB) and left anterior fascicular block (LAFB). LGE-MRI quantification of atrial tissue fibrosis was performed. Patients were staged as follows: Utah stage I (atrial fibrosis 35%). Patient demographics and clinical data were included in the analysis.
Results: The average QRS duration in Utah stage I was 92±11 ms, 95±18 ms in stage II, 96±19 ms in stage III and 100±26 ms in stage IV (p<0.05). 42 patients (9.83%) had RBBB, 17 (4.0%) had LAFB and 10 (2.3%) had LBBB. CSD was found in 3 of 27 (11.1%) in Utah stage I, 46 of 274 (16.8%) in stage II, 10 of 97 (10.3%) in stage III and 10 of 29 (34.5%) in stage IV (p<0.05). 195 patients (46%) were in AF at baseline. Regression analysis adjusting for age, gender, coronary disease, congestive heart failure, baseline AF, beta blockers, calcium channel blockers and class I anti-arrhythmics showed Utah stage 4 yielding an odds ratio of 2.7 (p=0.02; 95% CI 1.2-6.4) for CSD.
Conclusions: Advanced stage atrial tissue remodeling quantified using LGE-MRI is associated with slower ventricular depolarization and a higher prevalence of ventricular conduction system disease.
- © 2012 by American Heart Association, Inc.