Abstract 1879: Global Lv Strain Is An Accurate Measure For Scar Extent After Myocardial Infarct. A Comparison Of Longitudinal, Circumferential And Radial Strain Measurements
Purpose: Recent progress by speckle tracking echocardiography (STE) provides the opportunity to assess left ventricular (LV) function in 3 dimensions. We studied LV longitudinal, circumferential and radial strain and calculated which strain parameter that correlated best to myocardial scar mass in patients with chronic ischemic heart disease.
Methods: 40 patients (aged 58 ± 10 years, 9 women) were studied 8.5 ± 5.4 months after a first myocardial infarction. LV infarct mass was estimated by late enhancement MRI and compared to global LV strain. Global LV strain is calculated by averaging all segmental peak systolic strain values by STE in a 16 segment model. Longitudinal strain was assessed from 3 apical views, and circumferential- and radial strain from 3 short axis slices (apical, mid and basal).
Results: In average, 7.9 ± 4.1 segments and a total of 34 ± 27g were infarcted. Transmural infarct (≥50% transmural) was found in 25 patients. All global strains correlated significantly with infarct mass (figure⇓). In a ROC analysis, longitudinal strain was superior to identify substantial (≥30g) myocardial infarcts (sensitivity = 0.80, specificity = 0.85). Circumferential strain was best to identify minor (≥5g) myocardial infarcts (sensitivity = 0.82, specificity = 0.86).
Conclusion: Assessment of strain in all 3 major dimensions reflects decreased LV function due to ischemic myocardium. Global longitudinal- and circumferential- strains are excellent markers to identify patients with myocardial infarct.