IgG4 related cardiac disease.

IgG4-related systemic disease is an inflammatory disorder that can affect many organs. This case report describes a patient who in 2004 was found to have an inflammatory pseudotumor with IgG4 pathology. Over the next 3 years, visual symptoms responded well to recurrent courses of prednisone. In 2009, the patient developed chest pain and bradycardia with subsequent third-degree heart block, necessitating placement of a pacemaker. A subsequent PET scan showed extensive involvement of multiple organs as described in IgG4 disease as well as involvement of the myocardium and SA node. Pseudotumors involving the heart have been reported but have not been shown to be related to IgG4 disease. Although there was no pathology confirmation of heart involvement, the nature and extent of the organ involvement led us to conclude that it was due to IgG4-related disease. The use of the PET scan may help identify involvement of the myocardium.