Dyspnoea in a patient with biopsy-proven pulmonary sarcoidosis: the challenges in diagnosing cardiac sarcoidosis

A man in his 60s with biopsy-proven pulmonary sarcoidosis, not on treatment, presented with 6 weeks of dyspnea to the emergency department. ECG showed first-degree atrioventricular block and CT thorax demonstrated progressive pulmonary sarcoidosis with new multifocal consolidation. Antibiotics were initiated.A brain natriuretic peptide was elevated at 2024 ng/L and echocardiogram showed global left ventricular systolic dysfunction. Coronary angiogram revealed normal coronary arteries, and cardiac positron emission tomography and MRI demonstrated patterns compatible with cardiac sarcoidosis. The patient significantly improved with diuresis; he was started on prednisone, methotrexate and standard heart failure therapies.We outline the difficulties of attributing cardiac causes of dyspnoea in a patient with known pulmonary sarcoidosis given the rarity of cardiac involvement. We review proposed diagnostic criteria for cardiac sarcoidosis using enhanced imaging techniques without requiring invasive myocardial biopsy. This case discussion also highlights nuances in managing cardiac sarcoidosis based on the best available evidence and expert consensus.