[Viable myocardium evaluation by two dimensional speckle tracking imaging combined with adenosine stress echocardiography].

OBJECTIVE: Regional 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). METHODS: Two 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. CONCLUSIONS: Speckle tracking imaging combined with adenosine stress echocardiography could serve as a new and reliable method of assessing myocardial viability.

Clinic value of two-dimensional speckle tracking combined with adenosine stress echocardiography for assessment of myocardial viability.

BACKGROUND: To evaluate whether myocardial strain under adenosine stress calculated from two-dimensional echocardiography by automatic frame-by-frame tracking of natural acoustic markers enables objective description of myocardial viability in clinic. METHODS AND RESULTS: Two-dimensional echocardiography and two-dimensional speckle tracking imaging (2D STI) at rest were performed first and once again after adenosine was infused at 140 ug/kg/min over a period of 6 minutes in 36 stable patients with previous myocardial infarction. Then radionuclide myocardial perfusion/metabolic imaging served as the "gold standard" to define myocardial viability was given in all patients within 1 day. Two-dimensional speckle tracking images were acquired at rest and after adenosine administration. An automatic frame-by-frame tracking system of natural acoustic echocardiographic markers was used to calculate 2D strain variables including peak-systolic circumferential strain (CS(peak-sys)), radial strain (RS(peak-sys)), and longitudinal strain (LS(peak-sys)). Those segments with abnormal motion from visual assessment of two-dimensional echocardiography were selected for further study. As a result, 126 regions were viable whereas 194 were nonviable among 320 abnormal motion segments in 36 patients according to radionuclide imaging. At rest, there were no significant changes of 2D strain between the viable and nonviable myocardium. After adenosine administration (140 ug/kg/min), CS(peak-sys) had a little change of the viable myocardium while RS(peak-sys) and LS(peak-sys) increased significantly compared with those at rest. In nonviable group, CS(peak-sys), RS(peak-sys), and LS(peak-sys) had no significant changes during adenosine administration. After adenosine administration, RS(peak-sys) and LS(peak-sys) in viable group increased significantly compared with nonviable group. Obtained strain data were highly reproducible and affected in small intraobserver and interobserver variabilities. A change of radial strain more than 9.5% has a sensitivity of 83.9% and a specificity of 81.4% for viable whereas a change of longitudinal strain more than 14.6% allowed a sensitivity of 86.7% and a specificity of 90.2%. CONCLUSIONS: 2D STI combined with adenosine stress echocardiography could provide a new and reliable method to identify myocardium viability.