Abstract 16771: Feasibility of Noninvasive Assessment of Tissue Property in the Fibrotic Infarcted Myocardium Using Speckle Tracking Echocardiography
Background: Early systolic lengthening (ESL) and post-systolic shortening (PSS) is subtle myocardial deformation that occurs in the ischemic myocardium and is easily assessed by spekle tracking echocardiography. Because ESL and PSS in the ischemic region is caused by tension from the surrounding nonischemic region, such deformation may be attenuated in the infarcted myocardium with advanced fibrosis, which is less stretched by tension. We investigated whether the echocardiographic assessment of ESL and PSS can estimate tissue property in the fibrotic infarcted myocardium.
Methods: In 20 rats, the left anterior descending coronary artery was occluded and short-axis images were acquired at 1 day (1D, n = 7), 1 week (1W, n = 5), and 4 weeks (4W, n = 8) after the occlusion using GE Vivid 7 (frame rate = 235.4 fps). Circumferential strains were analyzed in the ischemic and nonischemic regions, and amplitudes of ESL (εESL) and PSS (εPSS), and the sum of εESL and εPSS (εESL+PSS) were measured. At the end of the protocol, Masson’s trichrome staining was performed on excised hearts to measure the area of fibrous tissue within the infarcted myocardium.
Results: The fibrous areas in the 1W and 4W were significantly larger than the 1D (1D vs. 1W vs. 4W: 3.7 ± 5.5% vs. 66.5 ± 12.8% vs. 69.5 ± 17.1%). Although there was no significant difference in the fibrous areas between the 1W and 4W, more dense staining of fibers was observed in all of the 4W. In the ischemic region, εESL, εPSS, and εESL+PSS did not significantly change between the 1D and 1W. However, εPSS and εESL+PSS significantly decreased and εESL tended to decrease in the 4W compared to the 1W (1W vs. 4W: εPSS 3.4 ± 1.1% vs. 1.4 ± 1.3%, εESL+PSS 5.9 ± 1.8% vs. 2.4 ± 1.9%, p<0.05, respectively) (figure).
Conclusions: ESL and PSS was attenuated in the infarcted myocardium with advanced fibrosis. The assessment of such subtle deformation by speckle tracking echocardiography may estimate tissue property in the fibrotic infarcted myocardium.
Author Disclosures: Y. Hotta: None. T. Asanuma: None. K. Masuda: None. S. Nakatani: None.
- © 2015 by American Heart Association, Inc.