Abstract 2607: Impact Of Acute Myocardial Infarction On Perfusion In Non-infarct Related Territories. Study With Sestamibi G-spect Imaging
In the setting of acute STEM blood flow may be slower also in non infarct related arteries. This may impact perfusion beyond infarct zone. The aim of our study was to assess viability and perfusion in non-infarcted myocardium using sestamibi G-SPECT. 36 pts with anterior STEMI within 12 hours from pain onset were enrolled. All pts were hemodynamically stable (Kilip≤3) on admission, without prior myocardial infarction and underwent primary angioplasty (pPCI). Two G-SPECTs at rest were performed: SPECT 1 - sestamibi injected immediately before pPCI (scintigrams registered within 6 hrs from pPCI) and SPECT 2, performed 5– 8 days later. Perfusion of the myocardium was visually assessed and standard grading (0 – 4) for 17 segments was used, where 0 indicates no, 1 - mild, 2 and 3 moderate perfusion abnormalities and 4 - total lack of perfusion. Sum of perfusion segmental defects grades for each territory and for the whole myocardium produces respective Summary Defect Score (SDS) indices. Higher SDS indicates more severe and wider perfusion defect. Left anterior descending artery (LAD) territory consists of 7, right coronary (RCA) and left circumflex artery (LCX) territories consist of 5 segments. Separate SDS for LAD (SDS LAD), for RCA (SDS RCA) and for LCX (SDS LCX) territories were calculated for SPECT 1 and SPECT 2. Also SDS for basal RCA segments (SDS RCA basal) and for basal LCX segments (SDS LCX basal) were calculated to avoid bias related to overlapping of blood supply. Results are presented in Table⇓. Both total SDS and SDS indices for separate vessel territories decreased while left ventricle ejection fraction increased between G-SPECT 1 and G-SPECT 2 procedures.
Conclusions In pts with anterior STEMI and culprit lesion in LAD perfusion of inferior wall is significantly reduced in acute phase. This suggests that anterior STEMI may cause global myocardial ischemia even in patients without cardiogenic shock.