Abstract 2712: Effect of Left Ventricular Dyssynchrony and Resynchronization Therapy on Twist in Patients with Dilated Cardiomyopathy
Background: We evaluated the relationship between LV dyssynchrony and torsion in patients with dilated cardiomyopathy (DCM) at baseline and after cardiac resynchronization therapy (CRT).
Methods: 2D speckle tracking echocardiography was performed in 35 normal control subjects (age, 41 ± 15 yr, LVEF 67 ± 6%) and 58 patients with DCM (age, 58 ± 16 yr, LVEF 32 ± 10 %) and 13 DCM patients with dyssynchrony within 7 days after CRT. A standard deviation of the time to first peak radial strain (T-SD) was measured as the parameter of dyssynchrony and the dyssynchrony was defined as T-SD > 100msec. Peak LV torsion/twisting velocity were calculated as the maximum difference in rotation angle/rotation velocity between the base and apex.
Results: Max torsion and twisting velocities were less in patients with DCM with dyssynchrony than in DCM patients without dyssynchrony or in controls (Table⇓). Amplitude of max torsion was correlated negatively with T-SD(r = 0.76, p < 0.001), LVEF(r = 0.70, p < 0.001), LVESV(r = 0.61, p < 0.001) at baseline. A multivariate analysis showed the T-SD was the significant determinant of max torsion and untwisting velocity after adjusted for age and LVEF (max torsion: r = 0.79, p < 0.001, untwisting velocity: r = 0.74, p = 0.001). After CRT, T-SD became shorter than that before CRT (Table⇓), and change of max torsion was inversely proportional to the % change of T-SD (r = 0.61, p = 0.003).
Conclusions: LV dyssynchrony is the major determinant of the magnitude of LV systolic torsion and diastolic untwisting in patients with DCM before and after CRT. Therefore, LV torsional deformation could be a sensitive marker for LV dyssynchrony.