Strain rate imaging differentiates transmural from non-transmural myocardial infarction: a validation study using delayed-enhancement magnetic resonance imaging

• Published in: Journal of the American College of Cardiology 2005-09, Vol.46 (5), p.864-871
• Main Authors: Zhang, Yan, Chan, Anna K Y, Yu, Cheuk-Man, Yip, Gabriel W K, Fung, Jeffrey W H, Lam, Wynnie W M, So, Nina M C, Wang, Mei, Wu, Eugene B, Wong, John T, Sanderson, John E
• Format: Article
• Language: English
• Subjects: Acute Disease; Aged; Cardiology; Case-Control Studies; Contrast Media; Coronary Stenosis - diagnosis; Echocardiography, Doppler; Female; Gadolinium DTPA; Heart attacks; Heart rate; Hong Kong; Humans; Hypertension; Magnetic Resonance Imaging, Cine - methods; Male; Middle Aged; Myocardial Infarction - diagnosis; Myocardial Infarction - diagnostic imaging; NMR; Nuclear magnetic resonance; Time Factors
• ISSN: 0735-1097; 1558-3597
• DOI: 10.1016/j.jacc.2005.05.054

The aim of this study was to determine if strain rate imaging (SRI) correlates with the transmural extent of myocardial infarction (MI) measured by contrast-enhanced magnetic resonance imaging (Ce-MRI). Identification of the transmural extent of myocardial necrosis and degree of non-viability after acute MI is clinically important. Tissue Doppler echocardiography with SRI and Ce-MRI were performed in 47 consecutive patients with a first acute MI between days 2 and 6 and compared to 60 age-matched healthy volunteers. Peak myocardial velocities and peak myocardial deformation strain rates were measured. Location and size of the infarct zone was confirmed by Ce-MRI using the delayed enhancement technique with a 16-segment model. Contrast-enhanced MRI identified transmural infarction in 21 patients, non-transmural infarction in 15 (mean transmurality of infarct 72.3 +/- 10.6%), and another 11 patients with subendocardial infarction (-0.59 s(-1) detected a transmural infarction with high sensitivity (90.9%) and high specificity (96.4%), and -0.98 s(-1) >SRs >-1.26 s(-1) distinguished subendocardial infarction from normal myocardium with a sensitivity of 81.3% and a specificity of 83.3%. Peak myocardial deformation by SRI can differentiate transmural from non-transmural MI, and it allows noninvasive determination of transmurality of the scar after MI and thereby the extent of non-viable myocardium.