Left and right atrial speckle tracking: Comparison of three methods of time reference gating.

BACKGROUND: Atrial function has a close interdependence with ventricular function and plays a central role in maintaining optimal cardiac function. There are two well-defined timing methods used to determine the start point. The aim of this prospective study was to objectively assess the influence of gating method selection on reported left and right strain values within the same group of healthy subjects. METHODS: 101 volunteers (44 male, 57 female) had adequate tracking for analysis on TomTec Imaging Systems (Unterschleissheim, Germany). The median age was 41 years (range 19-79 years, interquartile range 30-52 years). Atrial strain by 2D-speckle tracking echocardiography was evaluated using two commonly applied zero baseline time reference methods: R-R gating and P-P gating, in addition to volume gating (defining end-systole at the atrial maximum and end-diastole at the atrial minimum). RESULTS: True atrial minimum occurred prior to the onset of the QRS in most healthy volunteers. There was a significant difference for LA and RA reservoir strain between volume gating and R-R gating (mean difference, 4.63%; P < .001 for LA; mean difference, 4.23%; P < .001 for RA), as well as volume gating and P-P gating (mean difference, 5.26%; P < .001 for LA; mean difference, 6.24%; P < .001 for RA). Noticeably, reservoir strain was comparable between R-R gating and P-P gating (mean difference, 0.58%, P = .06) in LA, but not on RA (mean difference, 2.02%, P < .001). CONCLUSIONS: There was variability in atrial strain values depending on the zero baseline time reference method used.

Right Atrial Deformation Using Cardiovascular Magnetic Resonance Myocardial Feature Tracking Compared with Two-Dimensional Speckle Tracking Echocardiography in Healthy Volunteers.

Speckle tracking echocardiography (STE), and more recently, cardiovascular magnetic resonance myocardial feature tracking (CMR-FT) provides insight into all phases of atrial function. The aim of our study was to compare all phases of RA strain using CMR-FT and STE and also assess the relationship between RA and LA strain. A total of 61 healthy volunteers with mean age of 45 ± 13 years had adequate tracking for analysis on CMR-FT and 2D-STE. Females had larger RA reservoir strain (39 ± 15% vs. 32 ± 13%, p = 0.046) and conduit strain (26 ± 12% vs. 20 ± 9%, p = 0.03) when compared to males, but was not the case with booster strain (14 ± 7% vs. 12 ± 6%, p = 0.45). In comparison with STE derived strain, the RA reservoir and conduit strain were not significantly different between CMR-FT and the three echocardiography gating methods (p > 0.05 for all). Noticeably, there were no significant differences in strain and strain rate between RA and LA function using CMR-FT (p > 0.05 for all). RA strain and strain rate using CMR-FT had fair and good intra- and inter-observer reproducibility and had superior reproducibility compared to STE derived strain.