Objective:To evaluate inflammation early in the infarct zone and its dynamic changes after acute myocardial infarction (AMI) using 18F-FDG PET imaging, and analyze its relationship with left ventricular remodeling progression (LVRP). Methods:Sixteen Bama miniature pigs (4-6 months old, 8 females) were selected. AMI models were established by balloon occlusion of the left anterior descending artery. 18F-FDG PET imaging was performed before AMI and at days 1, 5, 8, and 14 post-AMI to evaluate the regional inflammation response. 18F-FDG SUV ratio (SUVR) and the percentage of uptake area of left ventricle (F-extent) in the infarct zone, and the SUVRs of the spleen and bone marrow, were measured. Echocardiography and 99Tc m-methoxyisobutylisonitrile(MIBI) SPECT myocardial perfusion imaging (MPI) were performed at the above time points and on day 28 post-AMI to assess left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), left ventricular ejection fraction (LVEF), and myocardial perfusion defect extent. The degree of LVRP at day 28 post-AMI was defined as ΔLVESV(%)=(LVESV AMI 28 d-LVESV AMI 1 d)/LVESV AMI 1 d×100%. Data were analyzed using repeated measures analysis of variance, Kruskal-Wallis rank sum test and Pearson correlation analysis. Results:Twelve pigs were successfully modeled and completed the study. Inflammation in the infarct zone persisted until day 14 post-AMI. The SUVR of the infarct zone pre-AMI and at days 1, 5, 8, and 14 post-AMI were 1.03±0.08, 3.49±1.06, 2.93±0.90, 2.38±0.76, and 1.63±0.62, respectively ( F=49.31, P<0.001). The F-extent values in the infarct zone pre-AMI and at days 1, 5, 8, and 14 post-AMI were 0, (40.08±12.46)%, (40.00±12.76)%, (31.08±12.82)%, and 16.50%(7.25%, 22.00%), respectively ( H=37.61, P=0.001). There were no significant differences in the SUVRs of bone marrow and spleen before and after AMI ( F values: 0.69 and 0.77, both P>0.05). At day 1 post-AMI, both SUVR and F-extent in the infarct zone were significantly correlated with LVRP ( r values: 0.82 and 0.70, P values: 0.001 and 0.035). Conclusions:18F-FDG PET imaging can be used to evaluate inflammation in the infarct area and its dynamic changes after AMI. Inflammation in the infarct area is severe at day 1, and then gradually decreases. The extent and severity of inflammation visible on 18F-FDG PET imaging 1 d after AMI are closely related to LVRP.

Objective:To evaluate the left ventricular diastolic dyssynchrony (LVDD) and its influencing factors early after acute myocardial infarction (AMI) using phase analysis of SPECT gated myocardial perfusion imaging (GMPI).Methods:Bama miniature swines ( n=16) were subjected to establish AMI models. GMPI was performed before and 1 d after AMI to obtain the extent of myocardial perfusion defect (Extent, %) and left ventricular systolic dyssynchrony (LVSD)/LVDD parameters, namely the phase histogram bandwidth (PBW) and phase standard deviation (PSD). Meanwhile, left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), left ventricular ejection fraction (LVEF), and the ratio of early to late peak mitral diastolic flow (E/A) were obtained by echocardiography. Independent-sample t test, paired t test and Pearson correlation analysis were used to analyze the data. Results:Sixteen AMI swines were successfully created. Compared to baseline, Extent, LVEDV and LVESV significantly increased on 1 d after AMI ( t values: -11.14, -4.55, -6.12, all P<0.001), while LVEF and E/A significantly decreased ( t values: 10.16, 2.18, P<0.001, P=0.046). GMPI showed that the LVDD parameters PBW and PSD increased significantly on 1 d after AMI when compared to those at baseline((142.25±72.06)° vs (33.06±8.98)°, (56.15±26.71)° vs (12.51±5.13)°; t values: -6.11, -6.60, both P<0.001). There were significant differences between LVSD parameters and LVDD parameters (PBW: (109.06±62.40)° vs (142.25±72.06)°, PSD: (44.40±25.61)° vs (56.15±26.71)°; t values: -2.73, -2.20, P values: 0.016, 0.044). LVDD parameters PBW, PSD were negatively correlated with E/A after AMI ( r values: -0.569, -0.566, P values: 0.021, 0.022), and positively correlated with the Extent ( r values: 0.717, 0.634, P values: 0.002, 0.008). The phase analysis of SPECT GMPI to evaluate LVDD showed good intra-observer and inter-observe reproducibility (intraclass correlation coefficient (ICC): 0.953-0.984, all P<0.001). Conclusions:LVDD occurs early on 1 d after AMI, and can reflect left ventricular diastolic dysfunction. The Extent is correlated with LVDD significantly. Phase analysis of SPECT GMPI is an accurate method to evaluate LVDD and left ventricular diastolic function.

The paper analyzed the present status and the problems existed in medium and small contingency medical teams in military hospitals, made recommendations that standardized construction of medium and small contingency medical teams could be im -plemented through the approaches of consolidated leadership , proper support and performance evaluation .The paper also explored in detail the ways to realize the standardized management of contingency medical teams , so that the target of overall planning and manage-ment could be reached and the management level of contingency medical teams in military hospitals be increased .