Abstract 2007: Effects of Myocardial Viability Assessed by Strain Stress Echocardiography on Diastolic Function in Acute Myocardial Infarction
Purpose: Myocardial viability may influence the diastolic function of left ventricle (LV) reflecting chamber remodeling in the early phase after acute myocardial infarction (AMI). However, the precise relationship in human has not been determined yet. So we aimed to evaluate whether myocardial viability assessed by strain rate parameters on low-dose dobutamine echocardiography (LD-DSE) may influence on LV diastolic function and remodeling process in AMI.
Methods: In this prospective single center study, 134 consecutive patients with AMI and akinetic wall motion in at least two segments were enrolled and underwent LD-DSE on 5~9 days after the event. Myocardial viability was quantitatively evaluated by global peak systolic strain rate (psSR) and global time to peak of psSR. Within 6 hours after LD-DSE, left and right heart catheterization with the recording of LV end diastolic pressure and pulmonary capillary wedge pressure were performed. And then 6 months later, echocardiography and thallium scan with delayed image were followed.
Results: Patients (67.9% men, mean age 60.1±1.1years, 54.5% anterior wall, 53.7% ST-segment elevation) were tolerated LD-DSE without significant complications. 71.6% of patients underwent revascularization therapy. After 6 months later, LV ejection fraction was significantly increased from 48.7±1.1% to 52.0±1.1% (p=0.00) and LV end diastolic volume was significantly decreased from 94.6±4.0cc to 89.1±3.8cc (p=0.00). As we expected, global psSR at baseline of LD-DSE showed significant linear correlations with LV end diastolic pressure, E/E’ ratio and left atrial volume index (r=−0.43 and p=0.01, r=0.52 and p=0.00 and r=0.52 and p=0.00, respectively). And also global psSR at 10mcg of LD-DSE correlated with E/E’ ratio and left atrial volume index(r=0.52 and p=0.00 and r=0.36 and p=0.02, respectively). Interestingly, global psSR at 10mcg of LD-DSE correlated significantly with the change of LV end diastolic volume during 6 months follow-up (r=−0.42 and p=0.04).
Conclusions: Strain rate data on LD-DSE correlates with LV diastolic function in the early phase and chamber remodeling in 6 months follow-up after AMI. So strain stress echocardiography may provide useful prognostic information for LV remodeling in AMI.