Quantitative Assessment of Left Atrial Functional Changes in Patients with Atrial Fibrillation by Tissue Doppler Strain and 2-Dimensional Strain Imaging

Background and Objectives:Conservation of the normal atrial size and architecture by preventing the structural atrial remodeling that’s due to atrial fibrillation (AF) seems to be of prime importance for the management of AF patients. We attempted to assess the relevance of performing strain echocardiography for quantitatively assessing the left atrial (LA) status in AF patients. Subjects and Methods:Tissue Doppler strain and 2dimensional strain imaging were performed in 15 patients with chronic AF, in 15 patients with paroxysmal AF and in 15 healthy age-matched controls with using a GE vivid 7 dimension apparatus. The LA diameter, LA volume index and mitral inflow parameters were measured by standard echocardiography. Longitudinal peak strain and the strain rate were obtained from 2 different areas of the basal left atrial free wall and also the inter-atrial septum in the apical 4 chamber view with using the tissue Doppler strain. The mean peak systolic rate (Sm-SR), the peak early diastolic rate (Em-SR) and the peak late diastolic strain rate (Am-SR) were measured at the inter-atrial septum in the apical 4 chamber view with using the 2-dimensional strain imaging. Results:The peak strain/rate, the Sm-SR and the Em-SR were significantly reduced in the AF group as compared with the normal controls, and they were especially reduced in the chronic AF group. There were no significant differences for the LA size and A wave velocity between the paroxysmal AF group and the normal group; however, the peak systolic strain/rate, the Em-SR and the Am-SR were significantly lower in the paroxysmal AF group than in the normal controls. Conclusion:The lower values of atrial Sm-SR, Em-SR and Am-SR revealed that active contraction and passive stretching of the LA wall may be impaired in some patients suffering with paroxysmal AF even before LA enlargement occurs, and this is possibly because of reduced atrial compliance. Our results indicated that strain echocardiography enabled quantitatively precise assessment of the LA contractile function and it can provide clinically useful information concerning the early reversible atrial functional changes in patients suffering with AF, and especially in the paroxysmal AF patients. (Korean Circulation J 2006;36:786-793)