Global Left Ventricular Systolic Function Based on the Sum of Regional Myocardial Velocities During Exercise Echocardiography

Abstract

We sought to assess the relationship between global Doppler myocardial imaging (DMI) and left ventricular (LV) ejection fraction (LVEF) at both rest and exercise. We have previously demonstrated that global DMI correlates with LVEF at rest with low variability. LVEF by 2-dimensional echocardiography, systolic global tissue Doppler velocity (s-TDV), strain (S) rate (SR), and S were assessed in 122 patients. LVEF was measured at rest and at peak exercise, whereas DMI was performed at rest and immediately postexercise. The region of interest by color DMI was set to enclose the external myocardial border when the LV achieved its maximal dimension. The means of the DMI assessments in the 4- and 2-chamber apical views at rest and postexercise were measured to correlate with LVEF. Significant correlations were found between the LVEF and global s-TDV, SR, and S either at rest (r = 0.32, r = 0.50, and r = 0.33, all P < .001) or at exercise (r = 0.47, r = 0.63, and r = 0.40, all P < .001). The best differentiation of an abnormal from a normal LVEF (>or=50%) at rest was provided by s-TDV less than 1.8 cm/s (sensitivity 63%, specificity 78%, area under the curve [AUC] 0.76, confidence interval [CI] 0.63-0.90), SR greater than -0.50/s (sensitivity 90%, specificity 76%, AUC 0.86, CI 0.76-0.97), and S greater than -9% (sensitivity 83%, specificity 75%, AUC 0.81, CI 0.70-0.91); whereas at exercise it was provided by s-TDV less than 3.5 cm/s (sensitivity 75%, specificity 74%, AUC 0.79, CI 0.69-0.89), SR greater than -0.80/s (sensitivity 83%, specificity 81%, AUC 0.91, CI 0.86-0.96), and S greater than -11% (sensitivity 67%, specificity 69%, AUC 0.74, CI 0.63-0.85). Global DMI is a valuable tool to assess global LV function during exercise.