If there is any doubt about regional function, tissue Doppler strain is the fastest means of regional function analysis in a stress echocardiogram. Right panel: the yellow region of interest shows reduced systolic strain and marked post-systolic shortening at peak stress, suggesting inducible ischemia. This becomes particularly obvious if compared to the green region of interest which shows a normal strain curve. Note that the overall strain amplitude is similar in both segments. Left panel: inducible ischemia is distinguished from a pre-existing abnormality by demonstrating that the yellow region of interest shows a normal strain curve at rest. AVO, AVC, MVO, MVC – aortic and mitral valve opening and closure.