Background: In the descending arm of tricuspid annular plane systolic excursion (TAPSE), there is notch formation that corresponds to the contractile phase of the atrial strain curve. Theoretically, this notch formation stands for atrial contraction.
Aims: We aim to characterize notch formation on TAPSE, predictors of its existence, and its relationship with the right ventricle and right atrial strain (RAS) parameters.
Methods: Retrospectively selected 240 patients were investigated for the determinants of notch formation on TAPSE and the relationship between RAS and TAPSE. RAS was analyzed using 2D speckle tracking in a dedicated mode for atrial analysis and reported separately for the reservoir, conduit, and contractile phases.
Results: 71.7% ( n = 172) of patients had notch formation on TAPSE and 70.4% (n = 169) had a normal value of right atrial contractile strain (RASct). Most patients with notch formation also had preserved RASct (95.9%; P <0.001). In multivariable analysis, RASct (odds ratio [OR], 1.45; 95% confidence interval [CI]: 1.13-1.77; P = 0.020) remained significant with notch formation. Receiver operator characteristic (ROC) analysis demonstrated that a RASct of -19% was a cut-off for the presence of notch formation. ROC area was 0.897 (95% CI 0.844-0.951; P <0.001).
Conclusions: The changes in TAPSE configuration reflect the changes in the atrial contractile phase. The descending arm of TAPSE indicates RASct as to whether it is preserved or not. Notch formation persists if RASct is above -19%. So, an easier, more applicable, and more effortless tool, TAPSE, can be used as an indicator of the atrial contractile phase by its configuration in daily routine.
Keywords: atrial contractile strain; right atrial strain; tricuspid annular plane systolic excursion.