Objective Interpretation of Dobutamine Stress Echocardiography by Diastolic Dyssynchrony Imaging: A Practical Approach

Abstract

Postsystolic shortening is a sensitive maker of myocardial ischemia. The aim of this study was to investigate whether diastolic dyssynchrony imaging is useful for the objective interpretation of dobutamine stress echocardiography. Postsystolic shortening was detected by using tissue Doppler imaging displacement timing analysis: the delays of the displacement peaks from end-systole were displayed from green to red, depending on the preset time window on diastolic dyssynchrony imaging. Dobutamine stress echocardiography was performed in 59 patients with suspected coronary artery disease who presented with normal left ventricular wall motion at rest (age range, 44-83 years; 20 women). The optimal time windows for diastolic dyssynchrony imaging at rest and at peak dobutamine were determined by receiver operating characteristic analysis by measuring the delays of the displacement peaks in the left ventricular myocardial segments. Diastolic dyssynchrony imaging was performed using time windows of 100 msec at rest and 80 msec at peak dobutamine. The diagnostic power of diastolic dyssynchrony imaging was assessed with quantitative coronary angiography as the gold standard (>50% diameter stenosis) both at rest and at peak dobutamine. Coronary artery disease was present in 37 patients (63%). Diastolic dyssynchrony imaging at peak dobutamine predicted the presence of coronary artery disease with sensitivity of 89%, specificity of 77%, predictive accuracy of 85%, positive predictive value of 79%, and negative predictive value of 81%. Diastolic dyssynchrony imaging at rest yielded sensitivity of 62%, specificity of 73%, predictive accuracy of 66%, positive predictive value of 79%, and negative predictive value of 53%. Importantly, diastolic dyssynchrony imaging demonstrated excellent intraindividual (97%) and interindividual (90%) agreement. Diastolic dyssynchrony imaging is useful in the objective interpretation of dobutamine stress echocardiography.