Improved recognition of dysfunctioning myocardial segments by longitudinal strain rate versus velocity in patients with myocardial infarction.

Doppler tissue imaging (DTI) can measure myocardial velocities but velocities alone cannot distinguish active from passive wall motion, whereas this is possible by strain rate (SR) imaging (SRI). We evaluated the accuracy of SRI for recognition of abnormal regional systolic function compared with DTI, B-mode echocardiography, and anatomic M-mode in 24 patients with myocardial infarction who underwent gated stress Tc 99m sestamibi scan. Sensitivity and specificity for recognition of infarct segments were 91% and 84% for visual SRI, 63% and 73% for visual DTI, 78% and 71% for B-mode echocardiography, and 87% and 77% for anatomic M-mode, respectively. Peak SRs correlated with wall-motion assessment by B-mode echocardiography better than peak velocities (P =.66 vs.10), with less overlap between groups. Therefore, SRI improves evaluation of regional wall motion compared with DTI and conventional ultrasound techniques in patients with myocardial infarction, mainly because it identifies segments that are moving passively but not shortening normally.