REGIONAL MYOCARDIAL STRAIN: A QUANTITATIVE COLOR DOPPLER MEASURE FOR STRESS ECHOCARDIOGRAPHY
G Armstrong, A Pasquet, M Greenberg, T Marwick
Cleveland Clinic Foundation, Cleveland Ohio
Peak systolic myocardial color Doppler velocities (MDV) vary with ischemia, but are affected by adjacent segments and translation. Peak systolic strain (PSS) is a more local index obtained from integrating MDV gradients. We compared MDV and PSS for quantification of exercise echo (ExE).
Methods: Twelve patients with abnormal wall motion (WM) at rest and/or stress and ten normal volunteers underwent ExE. Color Doppler and 2D images were obtained simultaneously and digitized (VingMed System FiVe). Longitudinal basal and mid-segt MDV and PSS in the apical four chamber view were compared to 2D WM. ROC curves were constructed to identify normal (n) and abnormal (abn) with optimal sensitivity and specificity.
Results: Both MDV and PSS were less in abn than n at rest and Ex. In all normal segments (n=66) PSS was negative at rest and Ex., representing longitudinal shortening. In 11/21 abnormal segments, PSS was positive at Ex. (longitudinal elongation). Areas under ROC curves PSS (0.88) exceeded that for MDV (0.80) and MDV (0.83). At optimal thresholds of MDV (6.8 cm/s) and PSS (4%), the accuracy of PSS (87%) exceeded that of MDV (76%, p=0.05).
|
MDVn |
MDVabn |
PSSn |
PSSabn |
|
|
Rest |
5.3+2.1 |
4.1+2.0# |
-18.5+4.9 |
-4.7+10.7* |
|
Max |
10.0+3.8 |
4.4+3.9* |
-24.4+5.3 |
-1.1+10.1* |
|
Delta |
4.5+3.0 |
0.3+3.4* |
6.0+2.8 |
-3.7+8.7* |
|
% |
98+80 |
13+172$ |
35+24 |
-18+110# |
Conclusions: PSS appears more accurate for detection of abnormal wall motion during exercise echocardiography.
