Relationship of contrast-enhanced magnetic resonance imaging-derived intramural scar distribution and speckle tracking echocardiography-derived left ventricular two-dimensional strains

AIMS: Information is limited regarding the functional correlates of intramural scar burden in myopathic hearts. We aimed to explore the use of speckle tracking echocardiography selectively at three intramural locations, to investigate the variance in cardiac strains and their relationship to contrast-enhanced magnetic resonance imaging-derived scar distribution and global left ventricular systolic function. METHODS AND RESULTS: Fifty-nine patients with evidence of myocardial fibrosis on contrast-enhanced magnetic resonance imaging and 18 healthy subjects underwent speckle tracking echocardiography for measuring subendocardial, midmyocardial, and subepicardial strains in longitudinal, circumferential, and radial directions. Patients were divided into three categories of scar distribution: Group A, endocardial and midmyocardial; Group B, midmyocardial and epicardial; and Group C, transmural. When these patients were compared with 18 healthy control subjects, longitudinal left ventricular deformation was attenuated equally for all three groups, whereas circumferential strain was relatively well preserved. On multivariate analysis, circumferential strain and scar burden were independent determinants of left ventricular ejection fraction (R(2) = 0.57; P = 0.003 for strain burden and P = 0.01 for scar burden). CONCLUSION: Longitudinal strains are attenuated independent of myocardial scar location. This alteration in left ventricular deformation is associated with circumferential mechanics becoming a key determinant of global left ventricular pump function in myopathic hearts