Differentiating Cardiac Sarcoidosis from Arrhythmogenic Right Ventricular Cardiomyopathy: A Systematic Review

Objective: Cardiac sarcoidosis (CS) and arrhythmogenic right ventricular cardiomyopathy (ARVC) are distinct disorders with different pathophysiologic pathways, but they share similar clinical presentations that could lead to misdiagnosis and inappropriate therapeutic decisions.

We searched PubMed and Google Scholar databases and other relevant literature to retrieve comparative studies including CS and ARVC that were published before 2024. The National Heart, Lung and Blood Institute checklist was used for quality assessment and the review was conducted according to the PRISMA guidelines. Three reviewers determined study eligibility and made quality assessments.

A total of seven studies were included in the review. Patients with CS were older (five of seven studies) and had more comorbidities (two of two studies). PR interval (four of five studies) and QRS duration (four of four studies) were longer in CS. Most studies reported lower left ventricular ejection fraction in CS (five of six studies), and septal involvement on cardiac MRI was more common in CS (two of three studies). 18-Fluorodeoxyglucose uptake on positron emission tomography (PET) scan was seen in up to 90% of CS patients. 62.5%-100% of patients with CS fulfilled 1994 or 2010 International Task Force criteria for ARVC.

Available evidence suggests that atrioventricular and intraventricular conduction defects in an older (>40 years) patient with low left ventricular ejection fraction should raise suspicion for CS, especially when other supportive findings, such as 18-fluorodeoxyglucose avidity on PET, were present. Neither 1994 nor 2010 ARVC Task Force criteria should be used to discriminate CS from ARVC.