Normal Range of Left Ventricular 2-Dimensional Strain - Japanese Ultrasound Speckle Tracking of the Left Ventricle (JUSTICE) Study

Background: To determine the normal range of left ventricular (LV) 2- dimensional (2-D) strain and vendor-specific differences, a multicenter prospective 2-D strain study endorsed by the Japanese Society of Echocardiography was conducted. Methods and Results: 2-D speckle tracking analysis was performed on 817 healthy subjects (age range, 0-88 years); the images included 3 LV short axis and 3 apical views using an ultrasound system from 1 of the 3 different vendors (V-1, n=333; V-2, n=330; V-3, n=337). With the 2-D speckle tracking software from each vendor, radial, circumferential and longitudinal strain were measured using an 18-segment model. Inter-vendor variability was also assessed in a subset of subjects. The feasibility for 2-D strain measurements was different among the 3 vendors (V-1, 83%; V-2, 70%; V-3, 88%, P<0.01). The global radial (V-1, 54.6 +/- 12.6%; V-2, 36.3 +/- 8.2%; V-3, 51.4 +/- 8.0%), circumferential (V-1, -22.8 +/- 2.9%; V-2, -22.2 +/- 3.2%; V-3, -30.5 +/- 3.8%), and longitudinal (V-1, -21.3 +/- 2.1%; V-2, -18.9 +/- 2.5%; V-3, -19.9 +/- 2.4%) strain measurements were significantly different for each of the vendors. Segmental strain was also different between the 3 vendors. On inter-vendor analysis, vendor agreement ranged from mild to moderate. Conclusions: Reference values are provided for normal 2-D strain for 3 different ultrasound vendors. Due to a low inter-vendor agreement, 2-D strain data are not interchangeable when conducting a longitudinal follow-up or a cross-sectional assessment of LV function. (Circ J 2012; 76: 2623-2632)