system
Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: OBJECTIVE, BACKGROUND, METHODS, RESULTS. Meshes: Aged, Coronary Stenosis, Dobutamine, Echocardiography, Doppler, Echocardiography, Stress, Female, Fluorodeoxyglucose F18, Heart, Humans, Image Enhancement, Male, Middle Aged, Myocardium, Predictive Value of Tests, ROC Curve, Reproducibility of Results, Sampling Studies, Sensitivity and Specificity, Tomography, Emission-Computed, Ventricular Dysfunction, Left.
user
Does strain rate measurement by doppler echocardiography allow improved assessment of myocardial viability inpatients with depressed left ventricular function? Context: This study sought to evaluate whether objective assessment of the myocardial functional reserve, using strain rate imaging (SRI), allows accurate detection of viable myocardium. Strain rate imaging is a new echocardiographic modality that allows quantitative assessment of segmental myocardial contractility. In 37 patients (age 58 +/- 9 years) with ischemic left ventricular dysfunction, myocardial viability was assessed using low-dose (10 microg/kg body weight per min) two-dimensional dobutamine stress echocardiography (DSE), tissue Doppler imaging, SRI and (18)F-fluorodeoxyglucose ((18)FDG) positron emission tomography (PET). The peak systolic tissue Doppler velocity and peak systolic myocardial strain rate were determined at baseline and during low-dose dobutamine stress from the apical views. A total of 192 segments with dyssynergy at rest were classified by (18)FDG PET as viable in 94 and nonviable in 98. An increase of peak systolic strain rate from rest to dobutamine stimulation by more than -0.23 1/s allowed accurate discrimination of viable from nonviable myocardium, as determined by (18)FDG PET with a sensitivity of 83% and a specificity of 84%. Receiver operating characteristic (ROC) curve analysis showed an area under the curve for prediction of nonviable myocardium, as determined by (18)FDG PET using SRI, of 0.89 (95% confidence interval [CI] 0.88 to 0.90), whereas the area under the ROC curve using tissue Doppler imaging was 0.63 (95% CI 0.61 to 0.65).
assistant
The increase in the peak systolic strain rate during low-dose dobutamine stimulation allows accurate discrimination between different myocardial viability states. Strain rate imaging is superior to two-dimensional DSE and tissue Doppler imaging for the assessment of myocardial viability. Final Decision: yes