Background: Aging affects left atrial (LA) function, which can be assessed by two-dimensional (2D) speckle tracking echocardiography (STE). The aim of this study was to determine (1) the feasibility and accuracy of measuring LA volume with 2DSTE and (2) the effects of aging on LA function.
Methods: 2DSTE of the LA was acquired from the apical 4-chamber view (frame rate: 63 +/- 11 /sec, iE33) using prototype speckle tracking software (QLAB, Philips Medical Systems, Andover, MA) in 140 healthy volunteers (3-79 years, 74 men). LA wall was tracked on a frame-by-frame basis, and LA volume waveforms were generated. Maximum LA volume (LAVmax) and minimal LA volume (LAVmin), and the LA volume before atrial contraction (LAVpre-a) were measured. Passive emptying percent of total emptying (LA conduit function) and active emptying percent of total emptying (booster function) were calculated as ([LAVmax-LAVpre-a]/[LAVmax-LAVmin]) x 100 and ([LAVa-LAVmin]/[LAVmax-LAVmin]) x 100.
Results: Adequate LA volume waveforms were obtained in all subjects. A good correlation was obtained between speckle tracking-derived LA volume measurements and manually traced LA volume measurements of the identical 2D image (LAVmax: r = 0.93, P <.001, LAVmin: r = 0.88, P <.001, LAVpre-a: r = 0.92, P <.001). Passive and active emptying indices had a significant age dependency (r = 0.80, P <.001). Overall, passive emptying accounted for 67% of the total LA emptying ranging from 83% in the youngest to 42% in the oldest decade.
Conclusion: Aging significantly affects LA conduit and booster function. 2DSTE can effectively and easily measure LA volume and has a potential for the noninvasive assessment of LA function.