Cardiac Sarcoidosis and Inherited Cardiomyopathies: Clinical Masquerade or Overlap?

Cardiac sarcoidosis (CS) and inherited cardiomyopathies (inherited CM) are associated with advanced heart failure, cardiac conduction defects, ventricular arrhythmias and sudden cardiac death. Both conditions can have similar clinical presentations. Differentiating between the two disease cohorts is important in delivering specific management to patients, such as immunosuppressive therapy for CS patients and genetic screening for inherited CM. In this review, we examined the existing evidence on the overlap between CS and common inherited CM, such as hypertrophic cardiomyopathy, arrhythmogenic cardiomyopathy, restrictive cardiomyopathy and dilated cardiomyopathy. In patients where both CS and inherited CM were implicated, CS tended to be diagnosed much later, often when patients presented with complications warranting a workup or cardiac histological confirmation. CS can masquerade as an inherited CM, leading to delays in the instigation of CS therapy. Confirmed dual pathology overlap between inherited CM and CS is rarer. Advanced cardiac imaging, such as cardiovascular magnetic resonance, plays an important role in the clinical workup of both CS and inherited CM. However, findings on cardiac imaging alone often cannot differentiate between the two conditions. Definitive differentiation between CS and inherited CM requires both clinical experience and, at times, a myocardial biopsy.