The harm of delayed diagnosis of arrhythmogenic cardiac sarcoidosis: a case series

Aims

Cardiac sarcoidosis (CS) is a known cause of ventricular tachycardia (VT). However, an arrhythmogenic presentation may not prompt immediate comprehensive evaluation. We aimed to assess the diagnostic and disease course of patients with arrhythmogenic cardiac sarcoidosis (ACS).

Methods and results

From the Leiden VT-ablation-registry, consecutive patients with CS as underlying aetiology were retrospectively included. Data on clinical presentation, time-to-diagnosis, cardiac function, and clinical outcomes were collected. Patients were divided in early (<6 months from first cardiac presentation) and late diagnosis. After exclusion of patients with known causes of non-ischaemic cardiomyopathy (NICM), 15 (12%) out of 129 patients with idiopathic NICM were ultimately diagnosed with CS and included. Five patients were diagnosed early; all had early presentation with VTs. Ten patients had a late diagnosis with a median delay of 24 (IQR 15–44) months, despite presentation with VT (n = 5) and atrioventricular block (n = 4). In 6 of 10 patients, reason for suspicion of ACS was the electroanatomical scar pattern. In patients with early diagnosis, immunosuppressive therapy was immediately initiated with stable cardiac function during follow-up. Adversely, in 7 of 10 patients with late diagnosis, cardiac function deteriorated before diagnosis, and in only one cardiac function recovered with immunosuppressive therapy. Six (40%) patients died (five of six with late diagnosis).

Conclusion

Arrhythmogenic cardiac sarcoidosis is an important differential diagnosis in NICM patients referred for VT ablation. Importantly, the diagnosis is frequently delayed, which leads to a severe disease course, including irreversible cardiac dysfunction and death. Early recognition, which can be facilitated by electroanatomical mapping, is crucial.

Ventricular Tachycardia Ablation in Nonischemic Cardiomyopathy

Catheter ablation is being increasingly performed as adjunctive treatment to prevent recurrent implantable cardioverter-defibrillator therapies in patients with nonischemic cardiomyopathy and ventricular tachycardia (VT). In the context of VT ablation, nonischemic cardiomyopathy usually refers to dilated cardiomyopathy (DCM) as one morphological phenotype. Over the past decades, progress has been made to better characterize distinct subtypes and to differentiate between causes of DCM, which has important practical and prognostic implications. The goal of this review is to summarize available data on VT ablation in patients with DCM and, more specifically, review procedural and outcome data in specific etiologies and substrate location. It will focus on our current understanding of nonischemic scars, as well as the value of multimodal imaging, image integration, and electroanatomic mapping for substrate identification, procedural planning, and ablation. In addition, recent findings from whole human heart histology of patients with DCM and VT and their potential implications for imaging and mapping will be discussed.