Systolic synchrony of ischemic myocardium assessed by stress-rest 99Tcm-MIBI gated SPECT myocardial perfusion imaging

Abstract

Objective To investigate the left ventricular synchrony under different ischemic statuses using phase analysis of 99Tcm-MIBI gated SPECT MPI (GSMPI). Methods The data of 129 patients (65 males, 64 females, age: 48-88 (68.6±10.2) years) who underwent 2-d stress-rest GSMPI were retrospectively analyzed. Perfusion images were scored by a 5-grade criteria (0-4) based on 17 coronary artery segments. Patients were divided into normal perfusion group (G1) and abnormal perfusion group (G2) according to the summed stress scores. G2 was divided into reversible perfusion defect subgroup (G2a) and irreversible perfusion defect subgroup (G2b) by the summed difference scores. The difference of PSD and PHB between groups and the difference between stress and rest GSMPI within each subgroup were compared using two-sample t test and paired t test, respectively. Results The numbers of patients in G1, G2, G2a and G2b were 66, 63, 39 and 24, respectively. The PSD (18.3±7.8) and PHB (68.6±30.9) of G2 were significantly higher than those (14.3±6.6 and 50.2±20.0) of G1 (t=-3.110, -3.989, both P 0.05), and the differences of PSD and PHB between rest and stress MPI within each subgroup were not significantly different (t: -0.961 to -0.114, all P>0.05). The PSD (20.4±8.1 and 20.8±6.4) and PHB (77.8±53.5 and 78.4±26.7) of rest and stress GSMPI in patients with LVEF ≤60% were significantly higher than those in patients with LVEF>60%(15.0±6.8 and 15.3±7.0, 53.5±23.0 and 55.9±24.5; t: 3.642 to 4.567, all P<0.05). Conclusions 99Tcm-MIBI GSMPI phase analysis can show damage effect of abnormal myocardial perfusion on left ventricular synchrony, which influencing global left ventricular function, and it can show different left ventricular synchrony due to different degrees of myocardial ischemia. There is nearly same value of stress GSMPI and rest GSMPI in assessment of left ventricular synchrony. Key words: Myocardical ischemia; Tomography, emission-computed, single-photon; Tomography, X-ray computed; MIBI; Adenosine triphosphate