Echocardiography was performed before and after treadmill tests in 30 patients to determine whether there is temporal variability in left ventricular wall motion abnormality with exercise-induced ischemia. The extent of wall motion was assessed by calculating systolic shortening in endocardial motion by two methods: (1) comparison between end diastole and end systole (ED-ES) and (2) frame-by-frame analysis throughout systole (integration). The extent of myocardial ischemia was assessed by stress thallium 201 emission tomography. Sensitivity of echocardiography for diagnosis of ischemia was 62% by ED-ES, but it increased to 83% by the integration method. Twenty-one percent of the ischemic area showed wall motion abnormality solely in the middle of systolic phase but not at end systole, and this occurred more at the reversible ischemic area (31%) than at the persistent ischemic area (19%). In conclusion, analysis throughout systole is important in detecting a reversible ischemic area.