Assessment of myocardial perfusion by harmonic power Doppler imaging at rest and during adenosine stress comparison with Tc-99m-Sestamibi SPECT imaging

Background-Harmonic power Doppler imaging (HPDI) is a novel technique for a ssessing myocardial perfusion by contrast echocardiography in humans. The p urpose of this study was to compare myocardial perfusion by HPDI with that obtained by Tc-99m-sestamibi single photon emission computed tomography (SP ECT) during rest and pharmacological stress, Methods and Results-HPDI was performed on 123 patients who were referred fo r SPECT imaging for known or suspected coronary artery disease. Images were obtained at baseline and during adenosine infusion (0.14 mg.kg(-1)min(-1)x 6 minutes) in 3 apical views. Myocardial perfusion by HPDI was graded for e ach coronary territory as absent, patchy, or full. The persistence of absen t or patchy myocardial perfusion by HPDI between rest and adenosine was int erpreted as a fixed defect, whereas any decrease in perfusion grade was int erpreted as a reversible defect. Overall concordance between HPDI and SPECT was 83 (81%) of 103 for normal versus abnormal perfusion. Agreement betwee n the 3 methods for each of the 3 coronary territories was 81% (kappa=0.57) for the left anterior descending artery, 76% (kappa=0.52) for the right co ronary artery, and 72% (kappa=0.40) for the left circumflex artery. Discrep ancies between the 2 techniques were most notable in the circumflex territo ry, where fixed defects were observed in 33% by HPDI but in only 14% by SPE CT (chi(2)=15.8, P=0.0001). Conclusions-This study demonstrates that HPDI can reliably detect myocardia l perfusion during pharmacological stress, although there was a significant ly higher number of falsely abnormal results in the circumflex territory.