The Value of 2D Strain Imaging during Stress Testing

Stress echocardiography is increasingly used but its major limitation is the subjective interpretation of wall motion changes requiring experience. Speckle tracking enables simultaneous evaluation of radial, longitudinal, and circumferential myocardial deformation. Recently, two-dimensional (2D) strain has been found to be as reliable as sonomicrometry for the assessment of left ventricular (LV) regional function. In the presence of inducible ischemia, longitudinal and circumferential abnormalities preceed the decrease in radial deformation. Optimal cutoffs have been obtained from 2D strain rate (SR) at peak dobutamine stress to predict coronary artery disease. However, 2D strain rate does not yet provide incremental accuracy to visual interpretation by experts. Speckle tracking strain could be useful to better identify contractile reverse and biphasic response of viable myocardium but there are not yet clinical studies published in this setting. Preliminary results suggest that 2D strain obtained during exercise could be useful in asymptomatic patients with severe aortic stenosis or organic mitral regurgitation (MR). In conclusion, the reliability and clinical importance of 2D strain during stress will be specified by further investigations. (ECHOCARDIOGRAPHY, Volume 26, March 2009)