Impact of early post-stress LV Dis-sinchrony assessed by TC99m GSPECT myocardial perfusion: ischemic patients vs. normal subjects

Abstract

Abstract Purpose We aimed to determine the value of early post-stress Tc99msestamibi gated SPECT imaging for detecting changes in the two phase analysis synchrony parameters: Histogram bandwidth (HB) and Standard deviation (SD) in ischemic patients compared to normal subjects. Methods We prospectively included normal subjects and consecutive patients who had a positive stress test (angina or ST deviation during stress test). Both groups followed the same GSPECT protocol: an early stress image (acquired at maximum 10 minutes after the tracer injection), a delayed stress image (after 45 min of tracer injection) and the rest image. Phase analysis indices HB and SD were compared from early stress/ rest images and delayed stress/rest images in both groups. We compared the change of SD and HB indices (stress minus rest) for early and delayed images. The ischemic group was divided into mild ischemia (SDS≤3), moderate ischemia (SDS>3 and<8), and severe ischemia (SDS≥8) Results Twenty nine normal subjects and 57 ischemic patients were included. Thirty per cent of the ischemic group had mild ischemia, 32% moderate ischemia and 37% severe ischemia. SD and HB values decreased in early and delayed-stress images compared to those of rest images in normal subjects (all p<0,05). In the ischemic group early-stress SD increased compared to rest SD (p<0,05) while delayed- stress SD did not change. Early-stress HB did not change in comparison to rest HB while delayed-stress HB decrease compared to rest HB.The figure shows the comparison of SD and HB between early-stress, delayed-stress and rest images in normal subjects and ischemic patients. The Table shows the comparison of the change of SD and HB indices (stress minus rest) for early and delay images. Conclusion LVMS indices obtained by phase analysis of Tc99sestamibi GSPECT imaging, HB and SD decrease significantly when derived from early and delayed stress images compared to rest images in normal subjects. A progressive significant increase in SD and HB values in delayed and early stress images was observed in this population what could be an expression of post-ischemic LV dis-synchrony. Larger amounts of ischemia are related to progressive higher changes in SD and HB from early and delayed stress images versus rest images. Funding Acknowledgement Type of funding source: None