A 56 year old woman presents after an episode of ventricular tachycardia. She has a history of dual chamber pacemaker placement 6 months ago for high grade atrioventricular block. In recent weeks, she reports greater frequency of palpitations and decreased exercise tolerance.
A stress-rest myocardial perfusion study was normal. She undergoes FDG PET imaging after completion of a non-carbohydrate diet for 24 hours:
PET/CT images abnormal increased FDG activity involving the aortic root and aortic valve, with additional abnormal activity in the region of the posterior papillary muscle.
Multiple small but hypermetabolic lymph nodes are noted in the mediastinum and bilateral axilla.
The patient also underwent a cardiac MRI.
3-chamber view cine SSFP images:
Short axis delayed-enhancement images:
MR images demonstrate moderate aortic regurgitation (see dark regurgitant jet extending inferiorly form the aortic valve) and abnormal delayed enhancement involving the aortic root and aortic valve.
This patient’s imaging findings are compatible with inflammation involving the aortic valve and aortic root, in this case due to cardiac sarcoidosis.
The preparatory non-carbohydrate diet prior to FDG PET/CT is used to suppress physiologic myocardial glucose/FDG uptake, so that any activity seen is due to an abnormal inflammatory process.
Valvular involvement by sarcoidosis is uncommon, thought to occur in less than 3 percent of patients with cardiac involvement and more often involving the mitral valve with associated papillary muscle involvement. Aortic root involvement by sarcoidosis is even more rare, but has also been reported.
Sekhri V, et al. Cardiac sarcoidosis: a comprehensive review. Arch Med Sci 2011;7:546-554. Gasparovic H, et al. Sarcoidosis of the aortic root. J Thorac Cardiovasc Surg 2004;128:761-762.
