Abstract 3141: Echocardiographic Two-Dimensional Strain Analysis Identifies Regional Myocardial Scar: A Comparison with Contrast-Enhanced MRI
Background: Contrast-enhanced MRI (ceMRI) can determine myocardial scar extent and location with great accuracy. The presence of transmural scar in the posterolateral region may result in poor response to cardiac resynchronization therapy.
Objective: To test the hypothesis that abnormalities in 2-dimensional strain echocardiography (2DS) correlate with transmural scar location by ceMRI.
Methods: Twenty-five patients with ischemic cardiomyopathy (ejection fraction 28 ± 9%) who underwent both ceMRI and 2DS were included. Extent of myocardial scar by ceMRI was scored visually at the base, mid, and apical short-axis levels using an 18-segment model. Transmural scar was defined as hyperenhancement extending > 50% of the segmental wall thickness. Analysis of 2DS was performed at corresponding short-axis levels using a novel speckle-tracking algorithm which tracks myocardial movement across the cardiac cycle (EchoPAC, GE). Peak circumferential and radial strain and strain rates were recorded for each myocardial segment.
Results: Peak circumferential strain was significantly reduced in segments with transmural scar (−6.9 ± 3.8%) versus non-transmural scar (−10.7 ± 5.8%, p < 0.0001). Similarly, peak radial strain was reduced in transmural versus non-transmural scar segments (7.9 ± 9.1% versus 13.3 ± 11.6%, p < 0.0001). When only the posterior or lateral segments were considered, both circumferential and radial strain values significantly differentiated transmural from non-transmural scar (p < 0.05).
Conclusion: Transmural scar is accurately identified by 2DS and may help guide pacemaker lead placement in patients undergoing cardiac resynchronization therapy.