Relation Between Right Ventricular Function and Increased Right Ventricular 18 FFluorodeoxyglucose Accumulation in Patients With Heart Failure

BACKGROUND: Left heart failure is characterized by alterations in metabolic substrate utilization, and metabolic modulation may be a future strategy in the management of heart failure. Little is known about cardiac metabolism in the right ventricle and how it relates to other measures of right ventricular (RV) function. This study was designed to measure glucose metabolism in the right ventricle, as estimated by (18)Ffluorodeoxyglucose (FDG) positron emission tomography imaging and to determine the relation between RV function and FDG uptake in patients with heart failure. METHODS AND RESULTS: A total of 68 patients underwent cardiac (18)FFDG positron emission tomography scanning with measurement of RV FDG uptake as a standardized uptake value. Perfusion imaging was acquired at rest with rubidium-82 or (13)Nammonia. RV function was determined by equilibrium radionuclide ventriculography. Relative RV FDG uptake was determined as the ratio of RV to LV standardized uptake value. Fifty-five percent of these patients had ischemic cardiomyopathy. The mean LV and RV ejection fractions were 21±7% and 35±10%, respectively. There was a correlation between RV ejection fraction and the ratio of RV to LV FDG uptake whether the entire LV myocardium (r=-0.40, P<0.001) or LV free wall (r=-0.43, P<0.001) was used. This relation persisted in the subgroup with nonischemic cardiomyopathy (r=-0.37, P=0.04). RV FDG uptake was weakly related to increased RV systolic pressure but not related to LV size, function, or FDG uptake. The correlation between RV ejection fraction and RV/LV FDG was maintained after partial-volume correction (r=-0.68, P<0.001). CONCLUSIONS: RV dysfunction is associated with an increase in RV FDG uptake, the magnitude of which may be correlated with severity.