Recent data has shown that sarcoidosis, presenting initially with cardiac manifestations (CS) of either conduction system disease or cardiomyopathy and sustained VT, is not uncommon. A Canadian physician survey found that most physicians do not investigate for CS as a possibility in these situations. Thus many patients with clinically important CS are going un-diagnosed. A study from Finland showed that missing the diagnosis of CS in these patients' leads to significant mortality and morbidity. There are no published clinical consensus guidelines on treatment of CS. Corticosteroid therapy is advocated by most experts. This is based on very modest data from small retrospective observational studies using variable definitions of clinical response. The effect of corticosteroid treatment on the clinical course of CS has not been studied in prospective studies and will be one of the aims of this project. Recent physician surveys regarding CS, in Canada and the US, found that current clinical practice varies widely. The 2008 American College of Cardiology/American Heart Association/Heart Rhythm society guidelines recommend implantation of a defibrillator (Class IIa recommendation) to prevent sudden cardiac death. The most recent Canadian device therapy guidelines do not mention CS. A multi-center collaborative approach to study CS is greatly needed. The investigators propose exactly that i.e. a multi-center prospective cohort to start to answer clinical questions. The investigators have formed the CANADIAN CARDIAC SARCOIDOSIS RESEARCH GROUP. The group includes respirologists with an interest in sarcoidosis, cardiac electrophysiologists, cardiac imaging specialists with extensive experience in imaging of sarcoidosis and biostatisticians. The research will be in two phases; a registry of current diagnostic approaches, treatment and prognosis, and a randomized clinical trial of the effect of corticosteroid treatment on the clinical course of cardiac sarcoidosis.