Objective: To study the feasibility of continuous intravenous SonoVue contrast echocardiography for qualitative assessment of reversible myocardial perfusion in dipyridamole stress tests.
Methods: Eleven patients (10 male and 1 female, mean age 66 years) with a history of chest pain and a clinical indication for stress sestamibi single photon emission computed tomography (SPECT) underwent concurrent SonoVue 99mTc myocardial contrast echocardiography (MCE).
Results: Of the total 176 segments obtained, 53 (30%) were regarded as indeterminate, 39 (22%) as discordant, and 84 (48%) as concordant between MCE and SPECT imaging. Two patients had abnormal SPECT results. The overall feasibility and specificity of MCE were 70 and 74%, respectively. The concordant (p = 0.59) and discordant (p = 0.55) segments were comparable with either MCE technique. However, continuous low-mechanical-index imaging produced fewer indeterminate segments (17 segments, 32%) than intermittent harmonic B-mode imaging (36 segments, 68%) (p = 0.04). Significantly more indeterminate segments were found in the left anterior descending artery territory. However, the overall concordance was similar (p = 0.5) in all three coronary artery territories. The concordance and discordance rates at different left ventricular levels (i.e., basal, mid, and apical) were similar (p = 0.50 and 0.08, respectively).
Conclusion: Continuous-infusion SonoVue contrast echocardiography is feasible, with high specificity, for detecting myocardial perfusion defects as assessed by dipyridamole SPECT.