Abstract 13427: Paroxysmal Atrial Fibrillation is Associated With Diffuse Left Ventricular Fibrosis
Background: Left ventricular (LV) interstitial tissue derangements and diffuse fibrosis have been described in diverse cardiac diseases and can be assessed non-invasively by CMR T1 mapping. Atrial fibrillation (AF) is associated with atrial fibrosis, but the associations with abnormal LV interstitium are unclear. We hypothesized that patients with paroxysmal AF would demonstrate CMR evidence of LV fibrosis, as manifest by decreased LV myocardial post contrast T1 time (increased fibrosis) compared to non-AF control patients.
Methods: We retrospectively identified all patients with paroxysmal AF referred for pre pulmonary vein isolation (PVI) CMR at our center between 2006 and 2011. Only data from patients in sinus rhythm during the CMR scan were included. A contemporary control group consisted of patients also in sinus rhythm and free of significant cardiac disease based on clinical and CMR findings. LV septal T1 times were derived from Look-Locker sequences after administration of gadopentetate dimeglumine.
Results: We studied 151 paroxysmal AF patients (59±10 years; 68% male; BMI: 29±5 Kg/m2) and 22 sinus rhythm controls (47±18 years, P=0.003; 63% male, P=0.6; BMI:26±6 Kg/m2, P=0.06). AF patients had shorter LV septal T1 time (365±57 vs 395±52 ms; P=0.01) and longer left atrial length (58±8 vs 52±9 mm; P=0.002), but similar LV end-diastolic volume index (81±16 vs 84±16 ml/m2; P=0.4), LV mass index (52±14 vs 55±14 g/m2; P=0.4), and LV ejection fraction (61±5 vs 61±6%; P=0.6). The associations persisted when the analyses were performed in a random subsample matched for sex, BMI and age .
Conclusions: Patients with paroxysmal AF show significantly lower post-contrast LV septal T1 times yet display normal LV anatomy and systolic function. These findings suggest that paroxysmal AF is associated with LV diffuse interstitial derangement which predates LV anatomic and functional remodeling.
- © 2013 by American Heart Association, Inc.