Sympathetic cardiac function in early sepsis: Noninvasive evaluation with [ 123 I]- meta -iodobenzylguanidine ( 123 I-MIBG) in vivo SPECT imaging

Sympathetic system abnormalities have been reported in sepsis-related cardiac dysfunction. the present study aimed at evaluating the potential of the norepinephrine radiolabeled analogue [123i]-meta-iodobenzylguanidine (123i-mibg) for the noninvasive assessment of modifications in cardiac sympathetic activity occurring in lipopolysaccharide (lps)-induced experimental acute sepsis by single-photon emission computed tomographic imaging (spect). sepsis was induced in male wistar rats by intraperitoneal injection of 10 mg·kg−1 lipopolysaccharide (n = 16), whereas control animals (n = 7) were injected with vehicle (nacl 0.9%). echocardiography in lps-injected animals (n = 8) demonstrated systolic and diastolic cardiac dysfunction. 123i-mibg was injected 1 hour after lps or vehicle administration (n = 8 and 7, respectively), and in vivo spect imaging was performed early and late (20 and 180 minutes) after tracer injection prior to animal euthanasia and ex vivo assessment of 123i-mibg biodistribution. global and 17-segment spect image analysis indicated that early 123i-mibg activity was not affected by lps treatment, whereas late cardiac tracer activity was significantly decreased in lps-treated animals. consequently, the cardiac washout of 123i-mibg was significantly higher in lps-treated (63.3% ± 4.0%) than that in control animals (56.7% ± 5.8%) (p < .05). sepsis-induced modifications in cardiac sympathetic nervous system activity were evidenced by noninvasive in vivo 123i-mibg spect imaging.