Reference values of right atrial longitudinal strain imaging by two-dimensional speckle tracking.

Background: The role of speckle tracking in the assessment of right atrial (RA) deformation dynamics has not been established yet. The reference ranges of RA longitudinal strain indices were measured by speckle tracking in a population of normal subjects. Methods: In 84 healthy individuals, peak atrial longitudinal strain (PALS), peak atrial contraction strain (PACS), and time to peak longitudinal strain (TPLS) were measured using a six-segment model for the RA. Strain rate (SR) was also measured starting from the QRS-wave onset, peak positive (x-wave), first peak negative (y-wave), and second negative peak (z-wave). The time from the QRS onset was measured to each wave peak. Results: Adequate tracking quality was achieved in 64% of segments analyzed. Inter- and intraobserver variability coefficients of measurements ranged between 6% and 11%. Global PALS was 49 ± 13%, global TPLS was 363 ± 59 msec, x-wave was 2.12 ± 0.58 sec−1, y-wave was −1.91 ± 0.63 sec−1, and z-wave was −2.18 ± 0.78 sec−1. Conclusion: Speckle tracking is a feasible technique for the assessment of longitudinal myocardial RA deformation. Reference ranges of strain indices were reported.