Abstract 2722: Adenosine Induced Perfusion Defects versus Dobutamine Induced Contraction Abnormalities for Diagnosis of Myocardial Ischemia: A Comparative Experimental Study with Contrast Echocardiography and 2D Strain
Background: For the clinical diagnosis of myocardial ischemia, perfusion analysis (i.e. SPECT) has been demonstrated to be more sensitive than regional function evaluation (stress echocardiography). Recently, quantitative analysis of myocardial regional function based on speckle tracking (2D strain) has been implemented in ultrasound systems with encouraging preliminary results.
Objectives: To compare adenosine induced defects by myocardial contrast echocardiography (MCE) to dobutamine induced contraction abnormalities by 2D strain for the diagnosis of myocardial ischemia.
Methods: 10 open-chest pigs were studied at baseline and at 4 stages of ischemia: mild and moderate LAD stenoses (non flow limiting stenosis (NFLS) at rest, but decreasing hyperemia by 30% and 50%, respectively), severe stenoses (flow limiting stenosis (FLS) at rest by 30% and 50%, respectively). Strain was studied at rest and during dobutamine infusion. Myocardial perfusion was performed by real-time MCE flash-replenishment method (A.b) with Sonovue® (Bracco) and quantified with QLab® (Philips) at rest and during adenosine infusion. References methods were sonomicrometry and microspheres, respectively.
Results: At baseline, myocardial blood flows and strain values were not significantly different between the different segments. During adenosine stress, significant perfusion defects appeared in presence of 30%NFLS in risk area (anterior and antero-septal walls). During dobutamine stress, circumferential strain significantly decreased in presence of 30%NFLS. Longitudinal strain decreased in presence of 50% NFLS. In contrast, radial strain was only significantly reduced in presence of 50%FLS.
Conclusions: MCE perfusion analysis during adenosine stress and function analysis with 2D strain during dobutamine stress allow early detection of ischemia at similar levels.