18F-FDG uptake in the heart of patients with atrial fibrillation

18F-FDG uptake in the heart of patients with atrial fibrillation Background: There are several ideas on the pathophysiology of atrial fibrillation (AF). One of the most common hypotheses is that inflammation may exist in the atrial walls of patients suffering from AF. Due to this hypothesized theory, we aimed to investigate the cardiac 18F-FDG uptake in patients with AF compared to patients without cardiac diseases. Methods: 82 adult patients were retrospectively enrolled. The cases (N=47) had a history of AF prior to the PET/CT scan. The controls (N=35) had no history of AF or other cardiac diseases. Both cases and controls used oral anticoagulants. Standardized uptake values (SUVmax) of the liver, heart, spleen and the psoas muscle were determined. The target to background ratios (TBR) of the liver, heart and spleen were obtained by dividing the targets by the background uptake (SUVmax of the psoas major muscle). Results: There was no significant difference in 18F-FDG uptake in the heart between the AF and control group (4.64 IQR: 3.06-6.59 against 3.71 IQR: 2.99-5.65, respectively; p=0,494). There was also no significant difference in 18FFDG uptake in the liver between the two groups (3.23 IQR: 2.72-3.91 against 3.40 IQR: 2.75-3.89; p=0.497). In contrast to the liver and heart, we found a significant difference in 18FFDG uptake in the spleen with a P value of 0.014. Conclusion: This case-control study showed no significant differences in the cardiac- and hepatic 18F-FDG uptake between patients with AF and patients without cardiac diseases. A statistically significant difference in the splenic 18F-FDG uptake has been observed.