Prediction of Deterioration of Left Ventricular Function Using 3‐Dimensional Speckle‐Tracking Echocardiography in Patients With Left Bundle‐Branch Block

BACKGROUND: Previous studies have demonstrated that 2‐dimensional (2D) global longitudinal strain (GLS) is associated with cardiovascular outcomes in patients with left bundle‐branch block. However, the predictive value of 3‐dimensional (3D) speckle‐tracking echocardiography has not yet been investigated in these patients. METHODS AND RESULTS: The authors retrospectively identified 290 patients with left bundle‐branch block who underwent echocardiography more than twice. Using speckle‐tracking echocardiography, 2D‐GLS, 3D‐GLS, 3D‐global circumferential strain, 3D global radial strain, and 3D global area strain were acquired. The association between 2D and 3D strains and the follow‐up left ventricular (LV) ejection fraction (LVEF) was analyzed. The study population was divided into 2 sets: a group with preserved LVEF (baseline LVEF ≥40%) and a group with reduced LVEF (baseline LVEF <40%). After a median follow‐up of 29.1 months (interquartile range, 13.1–53.0 months), 14.9% of patients progressed to LV dysfunction in the group with preserved LVEF, and 51.0% of patients showed improved LV function in the group with reduced LVEF. Multivariable analysis of 2D and 3D strains revealed that higher 2D‐GLS (odds ratio [OR], 0.65 [95% CI, 0.54–0.78], P<0.001) was highly associated with maintaining LVEF in patients with preserved LVEF. However, a lower 3D‐global circumferential strain (OR, 0.61 [95% CI, 0.47–0.78], P<0.001) showed a strong association with persistently reduced LVEF in patients with reduced LVEF. CONCLUSIONS: Although 2D‐GLS showed a powerful predictive value for the deterioration of LV function in the preserved LVEF group, 3D strain, especially 3D‐global circumferential strain, can be helpful to predict consistent LV dysfunction in patients with left bundle‐branch block who have reduced LVEF.