Abstract 713: Does Strain ST-T Change Reflect Subendocardial Dysfunction in Asymptomatic Hypertensive Left Ventricular Hypertrophy?: Demonstration by 2D Speckle Tracking Echocardiography
Background: Strain ST-T change on the surface ECG is known to reflect subendocardial dysfunction. We hypothesized that subendocardial dysfunction is accompanied with the reduction of longitudinal strain due to longitudinal direction of subendocardial fibers, and the reduction of a brief clockwise LV twist at early systole due to decrease in counteracting force from the subendocardium.
Methods: Three 2D LV short axis views and 3 apical views were acquired in 45 hypertensive LVH patients (64±12years, LVEF 64±7%) and 20 age-matched healthy volunteers (65±8years, LVEF 64±4%). Longitudinal, radial and circumferential strain and LV twist were measured using 2D speckle tracking echocardiography. Patients were divided into two groups according to the absence (n=28) or presence of strain ST-T change (n=17).
Results: LV mass index was significantly larger in patients with strain ST-T change (157±38g/m2) than no ST-T change (132±26g/m2, p<0.05). Longitudinal strain was significantly reduced in strain ST-T change group compared to no ST-T change group and normal volunteers. Although less pronounced, the same tendency was also observed for radial strain, but not for circumferential strain. LV peak twist was not different, but a brief clockwise twist at early systole was significantly reduced in strain ST-T change group. LV untwisting and untwisting rate was also depressed and delayed in strain ST-T change group.
Conclusions: Hypertensive patients with strain ST-T change were associated with the reduction of longitudinal function and a brief early systolic clockwise twist, which might reflect subendocardial dysfunction.