RT Journal Article
SR Electronic
T1 Regional Myocardial Perfusion Disturbance in Experimental Chronic Chagas Cardiomyopathy
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 1430
OP 1436
DO 10.2967/jnumed.117.205450
VO 59
IS 9
A1 Luciano Fonseca Lemos de Oliveira
A1 James T. Thackeray
A1 José Antônio Marin Neto
A1 Minna Moreira Dias Romano
A1 Eduardo Elias Vieira de Carvalho
A1 Jorge Mejia
A1 Denise Mayumi Tanaka
A1 Grace Kelly da Silva
A1 Douglas Reis Abdalla
A1 Carlos Malamut
A1 Frank M. Bengel
A1 Maria de Lourdes Higuchi
A1 André Schmidt
A1 Edécio Cunha-Neto
A1 Marcus Vinicius Simões
YR 2018
UL http://jnm.snmjournals.org/content/59/9/1430.abstract
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.