Abstract 3148: Clinical Significance of a New Ultrasound Method for the Simultaneous Assessment of Radial and Longitudinal Myocardial Deformation in Acute Myocardial Infarction: Validation with Delayed-Enhancement Magnetic Resonance Imaging
Strain (S) has been proposed as a tool to quantify regional myocardial function. One of the major pitfalls of the current methodology is its angle dependency. To overcome this problem, a new method for estimation of S - Axiustm 2D Velocity Vector Imaging (2DVVI) (Siemens Medical Solutions, Mountain-View, California)-, independent of angle, has been developed. We aimed to clarify the clinical significance of 2DVVI in assessing the transmural extent of acute myocardial infarction (AMI) by comparing 2DVVI to delayed contrast-enhancement (DCE) of magnetic resonance imaging (MRI). Methods: We examined 2DVVI and contrast-enhanced MRI in 30 patients with AMI. The new methodology was used to perform simultaneous measurements of radial and longitudinal S. According to the 16 segments as recommended by the American Society of Echocardiography, a total of 129 infarcted segments were enrolled and divided into 2 groups based on the extent of DCE by MRI: group 1= hyperenhancement > /= 75% of whole myocardial layer (n = 91) and group 2= hyperenhancement <75% (n=38). Group 1 and 2 were also independently compared with normal segments of age-matched healthy volunteers. Results: In all segments, it was possible to obtain adequate 2DVVI analysis. Both longitudinal and radial S were lower in transmural (group 1) (10 ± 6 % vs 17 ± 3%, p< 0.0001 and 10 ± 7% vs 16 ± 4%, p < 0.0001, respectively) and non-transmural (group 2) (10 ± 5 % vs 17 ± 3%, p < 0.0001 and 10 ± 5% vs 16 ± 4%, p < 0.0001, respectively) compared with corresponding normal segments. There was a significant relationship between longitudinal and radial S obtained by 2DVVI and increasing extent of DCE by MRI (longitudinal S group 1: 6 ± 4%, group 2 10 ± 5%, p<0.001; radial S group 1: 6 ± 4%, group 2 10 ± 5%, p < 0.0001). Conclusions: Strain measurement obtained by 2DVVI appeared to illustrate transmural extent of AMI. 2DVVI may have clinical significance in assessing myocardial viability in patients with AMI.