Diagnostic capability and reproducibility of strain by Doppler and by speckle tracking in patients with acute myocardial infarction.
OBJECTIVE
The objective of the present study was to investigate the ability of strain by Doppler and by speckle tracking echocardiography in the acute phase in patients with ST-segment elevation myocardial infarction (STEMI) to diagnose left ventricular (LV) infarct size. Furthermore, we wanted to study at which time during the cardiac cycle strain should be measured.


BACKGROUND
The assessment of regional myocardial dysfunction may be an important diagnostic tool in the evaluation of acute myocardial injury.


METHODS
Strain by Doppler and speckle tracking were assessed in the acute phase and after 10 days in 36 patients (61 +/- 11 years) with STEMI treated with thrombolysis. In a 16-segment model of the LV, peak systolic, end systolic, and peak negative strain were validated against the corresponding myocardial segments measured by contrast-enhanced cardiac magnetic resonance. The 16 segments were averaged to assess LV global longitudinal strain. In addition, 6 segments were analyzed from parasternal short-axis recordings at the papillary muscle level to assess circumferential strain. Reproducibility was tested in 20 patients.


RESULTS
The different segmental strain assessments separated significantly (p < 0.0001) between the different levels of infarct transmurality regardless of method, with better reproducibility for speckle strain. Circumferential strain separated better than longitudinal strain. With a cutoff value of -13.3% for segmental circumferential strain, sensitivity was 80% and specificity was 74% for prediction of transmural infarction. The LV global strain showed a good correlation with LV infarct size, with the best correlation for LV global peak systolic speckle strain (beta = 0.76, p < 0.0001).


CONCLUSIONS
On a segmental level, circumferential strain separated transmural from subendocardial necrosis better than longitudinal strain in the acute phase in patients with STEMI. Our findings suggest that in the acute phase in patients treated with thrombolysis, LV global peak systolic speckle strain should be the preferred method for predicting final LV infarct size.
Department of Medicine, Sørlandet Sykehus, Arendal, Norway.
Benthe
B
Sjøli
Stein
S
Ørn
Bjørnar
B
Grenne
Halfdan
H
Ihlen
Thor
T
Edvardsen
Harald
H
Brunvand
D000368:Aged; D004452:Echocardiography / Q000379:methods*; D018618:Echocardiography, Doppler, Color; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000187:drug effects*; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000503:physiopathology; D009206:Myocardium / Q000473:pathology*; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D015912:Thrombolytic Therapy; D013997:Time Factors; D016896:Treatment Outcome; D016277:Ventricular Function, Left / Q000187:drug effects*