Smiseth Otto A, Stoylen Asbjorn, Ihlen Halfdan
Department of Cardiology, Rikshospitalet University Hospital, Oslo, Norway.
Curr Opin Cardiol. 2004 Sep;19(5):421-9. doi: 10.1097/01.hco.0000135672.79534.e9.
Tissue Doppler imaging (TDI) is a diagnostic method that provides quantitative data about myocardial function. The present review discusses the most recent developments in the application of TDI in coronary artery disease.
The most widely used TDI modality is velocity imaging, and systolic function is measured as peak velocity during LV ejection. Several recent studies show that TDI measurements during the LV isovolumic phases provide unique information regarding myocardial dysfunction. Since velocity imaging is confounded by influence from velocities in other segments, the TDI-based modalities strain- and strain rate imaging (SRI) have been introduced to measure regional shortening fraction and shortening rate, respectively.Velocity imaging during stress echocardiography has been validated clinically and appears equivalent, but not superior to conventional visual assessment of grey scale images. Potentially, more comprehensive evaluation that includes the use of SRI may improve the diagnostic power of TDI further. Preliminary reports suggest that TDI may have an important role in the assessment of viability in acute coronary occlusion, but this needs to be demonstrated in appropriately designed clinical trials.
At the present time tissue Doppler velocity imaging can be recommended for clinical use, especially the pulsed mode. Strain rate imaging may be useful as additional imaging, but needs further refinement before it is ready for routine clinical use.
