Detection of small subendocardial infarction using speckle tracking echocardiography in a rat model

作者：Bachner Hinenzon Noa^*; Shlomo Liron; Khamis Hanan; Ertracht Offir; Vered Zvi; Malka Assaf; Binah Ofer; Adam Dan

来源：Echocardiography-A Journal of Cardiovascular Ultrasound and Allied Techniques, 2016, 33(10): 1571-1578.

DOI：10.1111/echo.13291

• myocardial infarction
• myocardial strain
• stunning
• viability

BackgroundIt is challenging to detect small nontransmural infarcts visually or automatically. As it is important to detect myocardial infarction (MI) at early stages, we tested the hypothesis that small nontransmural MI can be detected using speckle tracking echocardiography (STE) at the acute stage.
MethodsMinimal nontransmural infarcts were induced in 18 rats by causing recurrent ischemia-reperfusion of the left anterior descending (LAD) coronary artery, followed by a 30-min ligation and by reperfusion. A week later, the scar size was measured by histological analysis. Each rat underwent three echocardiography measurements: at baseline, 1day post-MI, and 1week post-MI. To measure the peak circumferential strain (CS), peak systolic CS, radial strain (RS), and time-to-peak (TTP) of the CS, short-axis view of the apex was analyzed by a STE program. The TTP was normalized by the duration of the heart cycle to create percent change of heart cycle.
ResultsHistological analysis after 1week showed scar size of 46% at the anterior wall. At 24h post-MI, the peak CS, peak systolic CS, and RS were reduced compared to baseline at the anterior wall due to the MI, and at the adjacent segmentsthe anterior septum and lateral wall, due to stunning (P<.05). However, only the anterior wall, the genuine damaged segment, showed prolonged TTP vs baseline (baseline 36%, 24h 48%, P<.05).
ConclusionThe TTP of the CS can distinguish between regions adjacent to MI (stunned or tethered) and MI, even in small nontransmural infarcts.

• 出版日期2016-10