Imaging characteristics of patients with cardiac sarcoidosis who presented with ventricular arrhythmias.

Background: Ventricular arrhythmia (VA) is an ominous manifestation of cardiac sarcoidosis (CS). Hence, identifying specific characteristics associated with VA in imaging modalities may enhance risk stratification.

Methods: Fifty-nine patients diagnosed with CS were retrospectively studied and grouped based on presenting symptoms as the VA group (sustained ventricular tachycardia and ventricular fibrillation) and the non-VA group (atrioventricular block, heart failure, and other symptoms). Thirty-nine patients underwent comprehensive evaluation by cardiac magnetic resonance imaging and ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG-PET) for comparing cardiac involvement distribution.

Results: The VA group (n = 15) showed higher prevalence of right bundle branch block, basal interventricular thinning, and left ventricle wall motion abnormality. In Cox analysis, VA at baseline (hazard ratio 4.75, p = 0.008) was associated with poor outcomes. The VA group showed a larger extent of late gadolinium enhancement than the non-VA group, especially in the left ventricular mid inferoseptal, right ventricular (RV) basal lateral to mid lateral, and RV apical anterior lesions. FDG-PET accumulation was prominent in the RV basal lateral to basal inferior, and mid anterior lesions in the VA group.

Conclusions: Patients who presented with VA had worse outcomes and a larger cardiac involvement predominant to the RV and ventricular septum; RV predominant scar pattern may serve as a surrogate in patients with CS and explain possible correlation with electrophysiological abnormalities.