Background: Unlike traditional Tissue Doppler Imaging (TDI), 3D speckle tracking (3DST) can quantify regional myocardial function in any spatial direction. The clinical relevance of this potential advantage has not yet been determined. We investigated if the different spatial strain components differ in their ability to define myocardial infarcts (MI).Methods: 13 patients with MI and 10 healthy volunteers (NORM) underwent TDI, 3D echo and MRI. Segmental systolic strain in longitudinal (3D-LS), circumferential (3D-CS) and radial (3D-RS) direction, as well as area strain (3D-AS) were measured with 3DST and compared to TDI derived longitudinal strain (TDI-LS). MRI delayed enhancement (DE) was used to group segments as remote (REM), non-transmurally (nonTM, <75% DE) or transmurally (TM, >76% DE) infarcted (INF). Receiver-operating curves were used to compare how TDI and 3DST derived parameters distinguish REM from INF, and TM from nonTM scar.Results: TDI-LS, 3D-LS, CS, RS and AS were sign. lower in INF compared to REM segments (-10±7% vs.-17±5%; -11±7% vs. -18±4%; -8±7% vs. -20±6%; 24±18% vs. 48±15%; -16±11% vs. -31±9%, resp., all p<0.001). REM segments in patients did not differ sign. from NORM (-17±5% vs. -19±4%, -18±4% vs. -20±4%, -20±6% vs. -20±5%, 48±15% vs. 55±16%; -31±9% vs. -34±7%, resp., all n.s.). All parameters detected the presence of INF segments and distinguished very well between nonTM and TM scar with comparable accuracy (see Figure). We found no sign. difference between TDI and 3DST derived parameters.Conclusion: Different 3DST derived strain components identify the localization and extent of MI equally good and are not superior to traditional TDI strain. The application of 3DST appears not necessary for the detection of ischemia induced abnormal regional function.