Metabolic activity of the left and right atria are differentially altered in patients with atrial fibrillation and LV dysfunction.

BACKGROUND

Alterations in atrial metabolism may play a role in the perpetuation of atrial fibrillation (AF). This study sought to compare 18F-fluorodeoxyglucose (FDG) uptake on PET, in patients with LV dysfunction versus those without AF.

METHODS

Seventy-two patients who underwent myocardial viability assessment were evaluated. AF patients (36) had persistent or permanent AF based on history and ECG. Patients without AF (36) were matched to AF patients based on sex, diabetes, age, and LVEF. Maximum and mean FDG Standard Uptake Values (SUV) in the left atrial (LA) wall and right atrial (RA) wall were measured. Tissue-to-blood ratios (TBR) were calculated as atrial wall to blood-pool activity. Atrial volumes were measured by echocardiography.

RESULTS

Maximum and mean FDG SUV and TBRs were significantly increased in the RA (but not the LA) of patients with AF compared to those without (P < 0.01). When accounting for changes in atrial volume, the presence of AF remained a significant predictor of higher RAMAX, but not RAMEAN FDG uptake.

CONCLUSION

In patients with LV dysfunction from ischemic cardiomyopathy, LA and RA glucose metabolism are differentially altered in those with persistent atrial fibrillation. Further investigations should elucidate the temporal relationship between AF and glucose metabolic changes, as a potential target for therapy.