PT - JOURNAL ARTICLE AU - Luciano Fonseca Lemos de Oliveira AU - James T. Thackeray AU - José Antônio Marin Neto AU - Minna Moreira Dias Romano AU - Eduardo Elias Vieira de Carvalho AU - Jorge Mejia AU - Denise Mayumi Tanaka AU - Grace Kelly da Silva AU - Douglas Reis Abdalla AU - Carlos Malamut AU - Frank M. Bengel AU - Maria de Lourdes Higuchi AU - André Schmidt AU - Edécio Cunha-Neto AU - Marcus Vinicius Simões TI - Regional Myocardial Perfusion Disturbance in Experimental Chronic Chagas Cardiomyopathy AID - 10.2967/jnumed.117.205450 DP - 2018 Sep 01 TA - Journal of Nuclear Medicine PG - 1430--1436 VI - 59 IP - 9 4099 - http://jnm.snmjournals.org/content/59/9/1430.short 4100 - http://jnm.snmjournals.org/content/59/9/1430.full SO - J Nucl Med2018 Sep 01; 59 AB - Altered myocardial perfusion is a common finding in chronic Chagas cardiomyopathy (CCC), but its underlying histologic changes have not been elucidated. We investigated the occurrence of myocardial perfusion defects (MPDs) and the correlated regional changes to histology in an experimental model of CCC in hamsters. Methods: Female Syrian hamsters (n = 34) were infected with 3.5 × 104 to 105 trypomastigote forms of Trypanosoma cruzi, Y strain, and 6–10 mo afterward underwent in vivo imaging including resting 99mTc-sestamibi SPECT, segmental and global left ventricular function assessment using 2-dimensional echocardiography, and 18F-FDG PET for evaluation of myocardial viability. Histologic analysis included quantification of fibrosis, inflammatory infiltration, and the diameter and density of myocardial microcirculation. Results: MPDs were present in 17 (50%) of the infected animals. Histologic analysis revealed no transmural scar in segments with an MPD, and normal or mildly reduced 18F-FDG uptake, indicating viable myocardium. Infected animals with an MPD, in comparison to infected animals without an MPD and control animals, showed a lower left ventricular ejection fraction (P = 0.012), a higher wall motion score index (P = 0.004), and a higher extent of inflammatory infiltration (P = 0.018) but a similar extent of fibrosis (P = 0.15) and similar microvascular diameter and density (P > 0.05). Segments with an MPD (n = 65), as compared with normally perfused regions in the same animal (n = 156), showed a higher wall motion score index (P = 0.005) but a similar extent of inflammatory infiltration, a similar extent of fibrosis, and a similar microvascular diameter and density. Conclusion: Resting MPDs are frequent in experimental CCC and are associated with myocardial inflammation but do not designate scar tissue, corresponding to regions with metabolically viable myocardium.