Post-exercise diastolic stunning detected by velocity vector imaging is a useful marker for induced ischemia in ischemic heart disease.

Abstract

Recently, post-exercise diastolic stunning (PES) has been reported as a new clinical marker of induced ischemia. Velocity vector imaging (VVI) has been developed to visualize regional wall motion abnormalities based on vectors detected by the tissue tracking technique, which has the potential to visualize PES. Thus, the aim of this study was to evaluate the usefulness of PES detection by VVI as an objective marker of ischemia compared to stress thallium-201 (Tl-201) single photon emission computed tomography (SPECT). We studied consecutive patients who were scheduled to undergo exercise stress Tl-201 SPECT for the diagnosis of ischemic heart disease. Transthoracic echocardiography was recorded digitally before and 20min after exercise for Tl-201 SPECT, and the data were used subsequently for VVI analysis. We defined PES regions as those with new abnormal vectors observed during isovolumic relaxation. After excluding 14 patients with old myocardial infarction and/or atrial fibrillation, echocardiograms suitable for VVI analysis were obtained from 62 of 65 patients (feasibility, 95%; 44 men; mean age, 64±11years). SPECT revealed induced ischemia in 20 patients, whereas VVI identified PES in 18 patients. VVI detected inducible ischemia with 85% sensitivity and 98% specificity compared to SPECT. VVI detection of PES is a new clinical tool for induced ischemia. Regional diastolic wall motion abnormalities following induced ischemia can be noninvasively detected by VVI.