In healthy subjects, endocardial torsion was significantly smaller than epicardial torsion (7.5° vs. 8.0°, p < 0.001), while circumferential torsion analysis was found to be unreliable.
Observational (n=12)
No
Variability in the position of the axis of rotation causes large variability in torsion in circumferential segments, but this effect is negligible for global and transmural layer torsion.
Tasa de eventos absoluta: 7.5% vs 8%
valor p: p=<0.001
PURPOSE: To introduce a standardized method for calculation of left ventricular torsion by CMR tagging and to determine the accuracy of torsion analysis in regions using an analytical model. METHODS: Torsion between base and apex, base and mid, and mid and apex levels was calculated using CSPAMM tagging and Harmonic Phase tracking. The accuracy of torsion analysis on a regional basis (circumferential segments and transmural layers) was analyzed using an analytical model of a deforming cylinder with a displaced axis of rotation (AoR). Regional peak torsion values from twelve healthy volunteers calculated by the described method were compared to literature. RESULTS: The deviation from the analytical torsion per % AoR-displacement (of the radius) was 0.90 +/- 0.44% for the circumferential segments and only 0.05% for the transmural layers. In the subjects, circumferentially, anterolateral torsion was larger than inferior (12.4 +/- 3.9 degrees vs. 5.0 +/- 3.3 degrees , N.S.). Transmurally, endocardial torsion was smaller than epicardial (7.5 +/- 1.3 degrees vs. 8.0 +/- 1.5 degrees , p < 0.001). CONCLUSION: Variability in the position of the AoR causes a large variability in torsion in circumferential segments. This effect was negligible for global torsion, and torsion calculated in transmural layers. Results were documented for the healthy human heart and are in agreement with data from literature.
Rüssel et al. (Tue,) conducted a observational in Healthy (n=12). CMR tagging and Harmonic Phase tracking was evaluated on Transmural torsion (endocardial vs epicardial) (p=<0.001). In healthy subjects, endocardial torsion was significantly smaller than epicardial torsion (7.5° vs. 8.0°, p < 0.001), while circumferential torsion analysis was found to be unreliable.