We used 2D strain measurement to quantify segmental systolic function during exercise stress echocardiography in 12 pts with AP and positive/borderline ECG stress test (Group 1) and in 14 pts without AP and with negative ECG stress test (Group 2). 2D-strain was obtained in parasternal short axis view and in the three apical views at rest and immediate post peak stress. Peak systolic strain rate (SR) and endsystolic strain (e) were measured off-line. Segmental quantification was compared with wall motion analysis in at least two adjacent segments. We used 16 myocardial segments model. The ROI was tracked manually at the end-systolic frame of the 2D images in a mid-myocardial position. SR criteria for myocardial ischemia were: delta SR <50% and SR at post peak stress <-2/s (apical septum), <-1,8/s (basal inferolateral segment), and <-1,7/s (mid inferior segment). Data are expressed as mean ±SD and as percentage of segments.
Pts with bad gray scale image, LBBB, severely depressed LV function and significant valvular heart disease were excluded.
Results: 2D SR could be adequately measured in 92% segments at rest and in 64% segments at post peak stress. Average 2D longitudinal and circumferential systolic strain parameters were significantly lower /p< 0.01/ in group 1 pts. Delta SR <50% was found in 10 pts of the Group 1 and in 3 pts of the Group 2. SR at post peak stress in segmental analysis was positive in 9 Group 1 pts and in 3 Group 2 pts (negative ischemic cascade). WMSI at rest and post peak stress was 1.12 ±0.5 and 1.1 ±0.4 in Group 1 and 1.2 ±0,7 and 1.4 ±0,6 in Group 2.
Conclusion: Speckle-derived strain could be, especially at rest, despite some limitations (image quality influence, lower frame rate), applicable supplement to exercise stress echocardiography in detecting myocardial ischemia in practice. (