Diagnosing cardiac sarcoidosis has always been challenging: No single imaging modality has proved effective and cardiac biopsies have a very low sensitivity. 18F-2-fluoro-2-deoxy-D-glucose fluorodeoxyglucose (FDG) PET preceded by at least 12 hours of fasting has previously been demonstrated to have reasonable accuracy, however, in some patients physiological FDG uptake in the cardiac region hampers correct identification of sarcoid granulomas. Gallium Ga 68-DOTANOC is a conjugate of the somatostatin analogue Nal3-octreotide (NOC) and gallium Ga 68-labeled 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid (DOTA). We aim to study whether 68Ga-DOTANOC has superior sensitivity and accuracy than 18-FDG PET in diagnosing cardiac sarcoidosis. In addition, we aim to compare 18-FDG PET preceded by 12 hours fasting with 18-FDG PET during somatostatin blockade of insulin mediated cardiac glucose uptake.

Intervention:

• Study A: Subjects with biopsy proven sarcoidosis suspected of cardiac involvement (prone to arrhythmias, cardiac failure, unexplained dyspnea) are studied twice: 1) 18-FDG PET preceded by 12 hours fasting and 2) 18-FDG PET performed during a 2 hour somatostatin blockade (300 microgram/hour)/Heparin infusion.
• Study B: Subjects with biopsy proven sarcoidosis suspected of cardiac involvement are studied twice: 1) 18-FDG PET preceded by 12 hours fasting and 2) 68Ga-DOTANOC PET preceded by at least 6 hours fasting.

Inclusion Criteria:

• Biopsy proven sarcoidosis
• Suspected cardiac sarcoidosis

Exclusion Criteria:

• Ischemic heart disease
• Diabetes
• Cardiomyopathy

Patients with biopsy proven sarcoidosis suspected of having cardiac sarcoidosis