Normal left ventricular mechanical function and synchrony values by speckle-tracking echocardiography in the transplanted heart with normal ejection fraction

Background: The purpose of this study was to describe the normal values for strain (S), systolic strain rate (SRs) and synchrony by speckle-tracking echocardiography (STE) in heart transplant (HTx) recipients who had normal left ventricular ejection fraction (LVEF) and no clinically significant complications.

Methods: We evaluated S and SRs in 40 HTx patients at 1 year after transplant and 82 healthy controls with STE using velocity vector imaging.

Results: Mean (SD) global longitudinal S and SRs, respectively, were lower in the transplant group compared with controls [-13.43% (2.39%) vs -17.28% (2.30%), p < 0.001; -0.83 (0.15) s(-1) vs -0.96 (0.13) s(-1), p < 0.001]. These variables were good for differentiating between groups: area under the curve was 0.88 for S and 0.73 for SRs. The differences remained significant after adjustment for other clinical variables. Global circumferential S and SRs were similar between groups. The standard deviation of the global longitudinal S time to peak of the 16 segments for HTx and control groups, respectively, was 41.67 (13.53) milliseconds vs 32.57 (12.81) milliseconds (p < 0.001). With 58.2 milliseconds as a cutoff value to define left ventricular synchrony, only 3 (8%) of the HTx patients and 4 (5%) of the control subjects were above that value (p = 0.6).

Conclusion: To our knowledge, this is the first study describing normal values for S and SRs and synchrony by STE in a HTx population with normal LVEF: longitudinal S and SRs were reduced; circumferential deformation indexes were normal; and left ventricular synchrony was preserved.