Abstract 13718: Assessment of Regional Circumferential Myocardial Stress in Ischemic Cardiomyopathy Patients with Cardiac Multi-detector Computed Tomography
Introduction: We developed multi-detector computed tomography (MDCT)-based analytic software to compute regional circumferential myocardial stress using Janz's method. Using this software, we measured the regional circumferential end-systolic stress (ESS) variation in normal subjects and patients with ischemic cardiomyopathy (ICM).
Methods: Using 64-slice MDCT scanners, we studied 34 normal subjects (age 67±10 years, EF 68±7%), and 25 patients with ICM (age 64±10 years, EF 24±8%) secondary to anterior myocardial infarction. The left ventricle (LV) was divided into 16 segments, modified from the AHA 17-segment model (Figure, left). Regional average circumferential wall stress was computed at end-systole using 3-dimensional cine-MDCT images.
Results: The left ventricular end-diastolic (LVEDVI) and end-systolic (LVESVI) volume indices were significantly higher in the ICM patients than in the controls (LVEDVI 159±54 vs 62±14 ml/m2, LVESVI 126±49 vs 20±7 ml/m2, p<.01 for both). In the ICM patients, regional ESS was markedly elevated in all 16 LV segments compared with the corresponding segment in the controls (p<.05) (Figure, right). Regional ESS was higher in the “infarcted” segments, which were predominantly in the LAD, than in the “non-infarcted” ones, in the LCX (p=.02) or RCA (p<.01), in the ICM patients. There were no significant circumferential variations in regional ESS in the controls (ANOVA, p=.91), suggesting a uniform geometric factor for wall stress. The controls showed a gradation in regional ESS from the apex to base, with the lowest stress at the apex (apex 92±21, mid-LV 156±43, base 174±36 kdynes/cm2). A similar apex-to-base gradation was seen in the ICM patients (apex 294±121, mid-LV 381±164, base 414±185 kdynes/cm2).
Conclusions: MDCT-based assessments of regional ESS are clinically feasible and provide new insight into regional myocardial functional assessment not only in patients with ICM but with a various cardiac diseases.
- © 2010 by American Heart Association, Inc.