['To evaluate left ventricular (LV) dyssynchrony in patients with left ventricular hypertrophy (LVH), and to compare abnormalities associated with hypertrophic cardiomyopathy (HCM) and hypertensive heart disease (HHD) using 2D speckle tracking imaging.', 'Basal, middle, and apical 2D LV short-axis images were acquired in 43 patients with LVH including 20 with HCM and 23 with HHD, and in 15 age-matched controls. Radial strain, circumferential strain, time interval from the R-wave to peak radial strain (Trs), and time to peak circumferential strain (Tcs) were measured in six equidistant segments at each level of the 3 LV short-axis views using 2D speckle tracking analysis. To assess LV dyssynchrony, Trs(cs)-18SD, the standard deviation (SD) of Trs(cs) in all 18 segments, was calculated.', 'Regional radial strain in the middle and apical short-axis segments was significantly less in patients with HCM than in those with HHD. Regional circumferential strain in the apical short-axis segments was also less in HCM. Trs-18SD and Tcs-18SD were significantly longer in patients with HCM than in age-matched controls and patients with HHD (Trs-18SD: HCM: 88 +/- 32 ms, HHD: 51 +/- 20 ms, control: 45 +/- 12 ms P < 0.001, Tcs-18SD: HCM: 71 +/- 27 ms, HHD: 46 +/- 14 ms, control: 45 +/- 14 ms P < 0.001).'] Is hypertrophic cardiomyopathy associated with more severe left ventricular dyssynchrony than is hypertensive left ventricular hypertrophy?