Substantial literature exists linking inflammation with arrhythmia, in particular with regards to serological markers of systemic inflammation. Regional inflammation can be identified usingÂ positronÂ emissionÂ tomographyÂ (PET) with the radiotracerÂ F18-fluorodeoxyglucoseÂ (F18-FDG). In the current series, we demonstrate novel applications ofÂ cardiacÂ PET using F18-FDG and N13-ammonia radiotracers in the evaluation and treatment of arrhythmia associated withÂ cardiacÂ sarcoidosis. These applications include defining the cause of arrhythmia,Â identifyingÂ arrhythmiasÂ that will be amenable to medical management, and guidingÂ therapyÂ usingÂ serialÂ scanning. Though these applications are promising, prospective multicenter studies are needed to provide better understanding of the utility of PET imaging in the diagnosis and treatment ofÂ arrhythmias.