To view the full text, please login as a subscribed user or purchase a subscription. Click here to view the full text on ScienceDirect. Illustrations of the 12-segment model of the LV. A, Mercator projection of the epicardial surface of the LV with the typical distributions of LAD (blue), RCA (green), and LCX (yellow).22 B, The orientation of the polar plot is given by the corresponding 12-segment model based on the Mercator projection. 1, Apical anteroseptal, 2, mid-anteroseptal, 3, basal anteroseptal, 4, apical anterosuperior, 5, mid-anterosuperior, 6, basal anterosuperior, 7, apical inferior, 8, mid-inferior, 9, basal inferior, 10, apical posterolateral, 11, mid-posterolateral, 12, basal posterolateral. Apical segments are placed in the center, basal segments, in the periphery. PDA indicates posterior descending artery. Polar plot representation of MaR. Polar plots generated from rest 99mTc-tetrofosmin SPECT perfusion, MRI wall thickening, and ECG for all patients (patient numbers are shown) with LAD, RCA, and LCX occlusion. Underneath each polar plot, the designated culprit arteries by the 2 observers are stated as observer 1/observer 2. Note the similarity in the location of MaR by the 3 modalities. The amount of myocardium at risk (MaR) during acute coronary occlusion and the duration of occlusion are important determinants of final infarct size. The main goal of early reperfusion therapy is to salvage ischemic myocardium, thereby preserving left ventricular function. The aims of the present study were to test the feasibility of developing polar plot representations of MaR, for perfusion single photon emission computed tomography (SPECT), regional wall thickening by magnetic resonance imaging (MRI), and distribution of ST-segment changes. A second aim was to test the hypothesis that these different modalities display similar localization of the MaR in patients with reperfused first-time myocardial infarction. Eleven patients with first-time myocardial infarction with ST-elevation received 99mTc tetrofosmin before primary percutaneous coronary intervention, SPECT imaging within 3 hours, and cardiac MRI of the left ventricle within 24 hours. The results for SPECT, MRI, and electrocardiogram (ECG) were developed into polar plots, and two expert observers designated the culprit coronary artery as assessed by angiography. The perfusion SPECT, MRI wall thickening, and ST changes are presented in side-by-side polar plots. In total, the culprit artery, based on the location of the MaR, was correctly designated in 91%, 82%, and 91% of cases by SPECT, MRI, and ECG, respectively. Polar representation for localization of the MaR by SPECT perfusion, MRI wall thickening, and ECG ST-segment deviation is feasible. All 3 modalities have the potential to be used for indirect visual designation of the culprit artery in patients with first-time acute coronary occlusion. If you are a current subscriber with Society Membership or an Account Number, claim your access now. ☆This study was funded by the Swedish Research Council, the Swedish Heart and Lung Foundation, the Medical Faculty at Lund University, Sweden, and Region of Scania, Sweden. Source.