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Cardiac sarcoidosis is a potentially life-threatening manifestation of systemic sarcoidosis characterized by non-caseating granulomatous inflammation of the myocardium, conduction system, or other cardiac structures.

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It is underdiagnosed and can lead to arrhythmias, heart block, heart failure, and sudden cardiac death.

https://www.youtube.com/watch?v=NGfWLmppEsQ

https://www.youtube.com/watch?v=UMvoqzfEZTI

https://www.youtube.com/watch?v=ZuIFOMgda14

Epidemiology

• Occurs in 5–25% of systemic sarcoidosis cases (clinically apparent)
• Autopsy studies suggest subclinical cardiac involvement in up to 50%
• More common in Japanese and African-American populations

Pathophysiology

• Granulomas infiltrate myocardium, conduction pathways, and sometimes valves or pericardium
• Leads to:
  • Myocardial scarring and fibrosis
  • Arrhythmogenic substrate
  • Systolic and diastolic dysfunction

![Clinical Features of Cardiac Sarcoidosis (Top left) Small patches of basal involvement, usually clinically silent disease. (Top right) Large area of septal involvement often clinically manifests as heart block. (Bottom left) Re-entrant circuit involving an area of fibrosis/granuloma leading to ventricular tachycardia. (Bottom right) Extensive areas of LV and RV involvement often clinically manifest as heart failure ± heart block ± VT.

LV = left ventricular; RV = right ventricular; VT = ventricular tachycardia.

Birnie DH, Nery PB, Ha AC, Beanlands RSB. Cardiac Sarcoidosis. Journal of the American College of Cardiology. 2016;68(4):411-421. doi:https://doi.org/10.1016/j.jacc.2016.03.605](attachment:700621f7-9a07-4cb6-9f82-1164475235b4:1-s2.0-S0735109716332739-gr1.jpg)

Clinical Features of Cardiac Sarcoidosis (Top left) Small patches of basal involvement, usually clinically silent disease. (Top right) Large area of septal involvement often clinically manifests as heart block. (Bottom left) Re-entrant circuit involving an area of fibrosis/granuloma leading to ventricular tachycardia. (Bottom right) Extensive areas of LV and RV involvement often clinically manifest as heart failure ± heart block ± VT.

LV = left ventricular; RV = right ventricular; VT = ventricular tachycardia.

Birnie DH, Nery PB, Ha AC, Beanlands RSB. Cardiac Sarcoidosis. Journal of the American College of Cardiology. 2016;68(4):411-421. doi:https://doi.org/10.1016/j.jacc.2016.03.605

Clinical Manifestations

Electrocardiographic Findings