Intraobserver reliability of two-dimensional ultrasound derived strain imaging in the assessment of the left ventricle, right ventricle, and left atrium of healthy human hearts.

AIMS: To determine the intraobserver reproducibility of peak and temporal values for myocardial strain (ɛ) and strain rate (SR) using a speckle tracking technique in the left ventricle (LV), right ventricle (RV), and left atrium (LA). METHODS AND
RESULTS: Myocardial speckle tracking echocardiograms of the LV, RV, and LA were obtained on 20 healthy adults to provide indices of longitudinal, radial, circumferential ɛ, and SR as well as LV rotation and twist. Each participant had two separate acquisitions approximately 30 minutes apart. No systematic bias was present in ɛ data. LV ɛ across all planes provided "good" to "very good" intraclass correlation coefficient (ICC) values (0.714-0.807), however radial ɛ was inferior in terms of coefficients of variation (CoV) (19%). SR data were more variable than ɛ with LV radial SR performing least favorably. RV and LA ɛ demonstrated excellent reproducibility (ICCs of 0.834, 0.959, and CoVs of 7% and 6%, respectively). RV and LA SR were again more variable but generally acceptable ICC > 0.6 and CoV < 15%. Peak basal and apical rotation demonstrated quite high variability while derived torsion had low variability and excellent agreement (ICC = 0.940, CoV = 10%). Time-to-peak values demonstrated acceptable agreement with the exception of systolic SR from all chambers.
CONCLUSION: Good reproducibility was obtained for peak ɛ indices although radial ɛ performs less favorably. Intraobserver variation of peak ɛ appears superior to values obtained for peak SR. Time-to-peak values demonstrate very good intraobserver reproducibility across all planes of contraction with exception of (time-to-peak) systolic strain rate (SRS).