Abstract 4228: Objective Judgment in Dobutamine Stress Echocardiography: Visualization of Post-Systolic Shortening by Tissue Doppler Imaging
Background: Although dobutamine stress echocardiography (DSE) is widely used for the detection of coronary artery disease (CAD), interpretation requires expertise. Post-systolic shortening (PSS) is a sensitive maker of myocardial ischemia. We have developed a novel tissue Doppler imaging (TDI) technique that readily visualizes the presence of PSS on 2-dimensional echocardiograms, and investigated whether CAD is objectively detectable by using this technique during DSE.
Methods: Detection of diastolic abnormality by displacement Imaging (DADI): PSS was detected by using tissue Doppler displacement timing analysis. In this method, end-systole was automatically determined from tissue velocity, and delays of the displacement peaks from the end-systole were displayed from green to red on the left ventricular apical views, depending on the preset time window. DSE was performed in consecutive 51 patients prior to coronary angiography (CAG) who underwent diagnostic CAG for suspected CAD, and presented with normal LV wall motion at rest (male=31, age ranged 44 – 83 years). We measured the time from the end-systole to displacement peak (ΔT) at each segment in the apical, mid and basal segments by the standard apical plane (long axis, 4 chamber and 2 chamber views). The optimal cut-off value of ΔT for discriminating normal from CAD was determined by receiver operating characteristic analysis. Finally, DADI was performed using the optimal ΔT. CAD was confirmed by CAG as having >75% diameter stenosis.
Results: Angiographic CAD was present in 31 patients (61%). DADI predicted CAD with sensitivity of 87%, specificity of 75%, negative predictive value of 79%, and predictive accuracy of 82% at the cut-ff ΔT of 80 ms at peak DSE.
Conclusion: DADI was useful in making objective judgment in DSE by readily portraying the presence of PSS, a marker of myocardial ischemia, on 2-dimensional echocardiograms in patients with inducible myocardial ischemia.