OBJECTIVERegional left ventricular (LV) function could be detected by measuring peak-systolic strain by speckle tracking imaging (STI). We evaluated the value of STI combined with adenosine stress echocardiography on assessing myocardial viability in patients with myocardial infarction (MI).

METHODSTwo dimensional echocardiography was performed at rest and after adenosine stress echocardiography (infused at 140 µg×kg(-1)×min(-1) over a period of 6 min) in 39 stable patients with previous MI. Peak-systolic (Speak-sys) circumferential strain, radial strain and longitudinal strain were assessed by STI. Radionuclide myocardial perfusion/metabolic imaging served as the "gold standard" to detection of myocardial viability.

RESULTS(1) There were 215 viable and 153 non-viable regions among 368 abnormal motion segments out of 624 segments in 39 MI patients according to radionuclide imaging results. (2) Speak-sys was similar between viable and nonviable myocardium at rest (all P > 0.05). After adenosine infusion, radial Speak-sys [(37.98 ± 5.45)% vs. (30.22 ± 5.47)%], longitudinal Speak-sys [(-23.71 ± 4.53)% vs. (-17.52 ± 4.34)%] increased significantly (P < 0.05)in viable segments compared to baseline levels and were significantly higher than in nonviable segments radial Speak-sys [(37.98 ± 5.45)% vs. (30.12 ± 5.37)%] and longitudinal Speak-sys [(-23.71 ± 4.53)% vs. (-16.95 ± 4.62)%] (P < 0.05), while remained unchanged in nonviable segments before and after adenosine infusion. Circumferential Speak-sys was similar before and after adenosine infusion in both viable and nonviable segments (all P > 0.05). (3) Delta radial strain change > 9.8% has a sensitivity of 82.3% and a specificity of 81.1% whereas a delta change of longitudinal strain > 16.5% has a sensitivity of 83.5% and a specificity of 92.3% for detecting viable segments.

CONCLUSIONSSpeckle tracking imaging combined with adenosine stress echocardiography could serve as a new and reliable method of assessing myocardial viability.