The assessment of atrial function by velocity-encoded magnetic resonance imaging

Introduction: The purpose of this study was to assess velocity-encoded cardiac magnetic resonance imaging (Ve-CMR) in a population of patients referred for cardiac magnetic resonance imaging (CMR), to determine the variability of atrial function, and to identify clinical parameters associated with left atrial function. Methods: This is a prospective study evaluating patients who were referred to our CMR center for a clinical CMR. Left atrial function was obtained via Ve-CMR thru-plane images across the mitral valve after acquiring 2 perpendicular in-plane images as “scouts”. The atrial function and mitral inflow were quantified by computer analysis (Argus, Siemens). Atrial function was defined as atrial contraction (Awave) volume divided by total inflow volume. Left atrial volumes were calculated via computer analysis. Mitral regurgitation and left ventricular ejection fractions were assessed visually. Results: Thirty-nine patients, with mean age 56 +/− 10 years, were enrolled. The mean left atrial function was 22.9% +/− 14.5%; the range in left atrial function was 0% 57%. There was a significant positive correlation between atrial function and increased left ventricular ejection fraction (r = 0.44, P < 0.01). There was a significant negative correlation between atrial function and severity of mitral regurgitation (r = −0.60, P < 0.01), as well as left atrial volume (r = −0.36, P = 0.02). Conclusion: Our results indicate a wide variability in left atrial function and a significant association between left atrial function and left ventricular ejection fraction, left atrial volume and mitral regurgitation.