Assessment of myocardial viability.

600 Assessment of resting perfusion with myocardial contrast echocardiography: a comparison with tecnetium single-photon emission computed tomography and dobutamine echocardiography C. Palagi r, G. Mengozzi 1, L. Rondinini 1, MG. Delle Donne 1, p. Caravelli 1, L. Papi 1, E. De Felice 1, D. Volterrani 2, CR. Bellina e, M. Mariani Cardio-Thoracic Dept., Cisanello Hospital, Pisa, Italy 1, Oncology Dept., Division of Nuclear Medicine, Pisa, Italy 2 The aim of this study was to perform a comparison between Myocardial Contrast Echocardiography (MCE) and Tecnetium Single-Photon Emission Computed Tomography (SPECT) for the detection of perfusion pattern in patients (pts) with reperfused Acute Myocardial Infarction (AMI). We also tried to determine the relation between MCE perfusion and contractile reserve on low-dose Dobutamine Echocardiography (DE). Forthy-three pts (36 m, 7 f, mean age 5+11 years) with first AMI and successful (TIMI flow grade 3) PTCA: 29 primary PTCA and 14 rescue PTCA underwent one month after AMI, intravenous MCE and TC-SPECT, within a week. A DE (5-10-20 ug/Kg/min) was also performed in 40 pts (3 pts showed no RWM abnormalities at one month 2D-Echo). MCE was carried out using Harmonic Power Doppler imaging after contrast agent venous injection. TC-SPECT was performed using stress-rest protocol. Left ventricle was divided in 16 segments, but only "(0 were studied because 6 were excluded for inadeguate gain setting or image quality with contrast agent. RESULTS: In the comparison between MCE and TC-SPECT 430 segments were evaluated. Concordance between the two methods was 72 %. During DE 400 segments were evaluated: 238 normokinetic and 162 with RWM abnormalities at rest. Out of 162 segments with RWM abnormalities, 70 showed a cotractile reserve during dobutamine infusion: in 63/'70 of these pertusion was detected by MCE. Out of 162 segments with RWM abnormalities, 92 segments showed no changes during dobutamine infusion: a severe perfusion defect was detected in 62/92 of these segments by MCE. Thus MCE sensitivity and specificity were 68 % and 90 %, respectively. CONCLUSIONS: Although the discrepancies between MCE and TC-SPECT with regard to the definition of moderate perfusion defects requires further investigation, MCE seems to be a reliable non invasive clinical tool in detecting myocardial perfusion. MCE seems to be a non invasive diagnostic method with high accuracy for detecting segments still viable after AMI.