Speckle tracking imaging improves in vivo assessment of EPO-induced myocardial salvage early after ischemia-reperfusion in rats.
A noninvasive assessment of infarct size and transmural extension of myocardial infarction (TEMI) is fundamental in experimental models of ischemia-reperfusion. Conventional echocardiography parameters are limited in this purpose. This study was designed to examine whether speckle tracking imaging can be used in a rat model of ischemia-reperfusion to accurately detect the reduction of infarct size and TEMI induced by erythropoietin (EPO) as early as 24 h after reperfusion. Rats were randomly assigned to one of three groups: myocardial infarction (MI)-control group, 45 min ischemia followed by 24 h of reperfusion; MI-EPO group, similar surgery with a single bolus of EPO administered at the onset of reperfusion; and sham-operated group. Short-axis two-dimensional echocardiography was performed after reperfusion. Global radial (GS(r)) and circumferential (GS(cir)) strains were compared with infarct size and TEMI assessed after triphenyltetrazolium chloride staining. As a result, ejection fraction, shortening fraction, GS(r), and GS(cir) significantly correlated to infarct size, whereas only GS(r) and GS(cir) significantly correlated to TEMI. EPO significantly decreased infarct size (30.8 + or - 3.5 vs. 56.2 + or - 5.7% in MI-control, P < 0.001) and TEMI (0.37 + or - 0.05 vs. 0.77 + or - 0.05 in MI-control, P < 0.001). None of the conventional echocardiography parameters was significantly different between the MI-EPO and MI-control groups, whereas GS(r) was significantly higher in the MI-EPO group (29.1 + or - 4.7 vs. 16.4 + or - 3.3% in MI-control; P < 0.05). Furthermore, GS(cir) and GS(r) appeared to be the best parameters to identify a TEMI >0.75 24 h after reperfusion. In conclusion, these findings demonstrate the usefulness of speckle tracking imaging in the early evaluation of a cardioprotective strategy in a rat model of ischemia-reperfusion.
Treguer
Frederic
F
Protection et Remodelage du Myocarde, UPRES EA 3860, Faculté de Médecine, Rue Haute de Reculée, F-49045 Angers Cedex 1, France.
Donal
Erwan
E
Tamareille
Sophie
S
Ghaboura
Nehmat
N
Derumeaux
Geneviève
G
Furber
Alain
A
Prunier
Fabrice
F
D000818:Animals; D015150:Echocardiography, Doppler / Q000379:methods*; D004921:Erythropoietin / Q000627:therapeutic use*; D023421:Models, Animal; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000473:pathology; D009206:Myocardium / Q000473:pathology; D009336:Necrosis; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000150:complications*; D016879:Salvage Therapy; D013997:Time Factors
D004921:Erythropoietin