Clin Res Cardiol (2023). https://doi.org/10.1007/s00392-023-02180-w

Substrates of ventricular arrhythmias in patients with autoimmune rheumatic diseases

T. Kling1, M. Metani1, Z. Aynur1, M. Ulbrich1, C. Reithmann1

1Medizinische Klinik I, Kardiologie, Helios Klinikum München West, München;

Introduction: Delayed enhancement - magnetic resonance imaging (DE-MRI) has demonstrated that ischemic cardiomyopathy is characterized by a subendocardial or transmural scar whereas intramural or epicardial delayed enhancement strongly suggests a nonischemic cardiomyopathy (NICM). Global subendocardial pattern of fibrosis without abnormal myocardial thickening was identified by DE-MRI in patients with different autoimmune rheumatic diseases (ARDs) such as lupus erythematodes or systemic sclerosis. Conduction disorders and sudden cardiac death are important manifestations of cardiac involvement in ARDs but the substrates of ventricular arrhythmias (VAs) in ARDs have not been fully elucidated. Aims: The purpose of this study was to characterize the substrates of VAs in patients with ARDs in comparison to other forms of NICM by DE-MRI and electroanatomical voltage mapping. We also studied whether damage of the specific conduction system may play a role in the mechanisms of VA in patients with ARDs.  Patients: 17 patients with cardiac involvement in ARD (12 male, 58+-19 years, left ventricular ejection fraction (LV-EF) 44+-10%) presented with sustained ventricular tachycardia (VT) (n=10), non-sustained VT (n=1) and frequent ventricular extrasystoles (n=6). Patients had immunosuppressive therapy for systemic lupus erythematodes (n=3), systemic sclerosis (n=1), psoriasis (n=7), rheumatoid arthritis (n=2), dermatomyositis/polymyositis (n=2) or eosinophilic granulomatosis with polyangiitis (n=2). 100 consecutive patients with other forms of NICM (86 male, 63+-11years, LV-EF 41+-14%) referred for electrophysiological study and/or ablation of sustained VT served as a control group  (exclusion: acute myocarditis, sarcoidosis and genetic cardiomyopathies). Methods: Extensive or global endomyocardial fibrosis was stated if fibrosis involved more than 50 % of the circumference of LV endocardium in DE-MRI or if very low voltage (< 0.5mV) covered more than 50 % of endocardium in LV voltage maps. VT with participation of the conduction system was defined as a VT with fascicular or Purkinje potentials preceding VT QRS at critical sites of the VT reentry circuit where fascicular or Purkinje potentials were also recorded during sinus rhythm. Results: DE-MRI was performed in 10 patients with ARDs and 38 patients with other forms of NICM. Endocardial voltage mapping was performed in 9 patients with ARDs and 81 patients with other forms of NICM. Extensive or global endomyocardial fibrosis was more frequenty found in patients with ARDs (9/17) than in patients with other forms of NICM (10/100). VTs with participation of the specific conduction system including bundle branch reentry were found more frequently in patients with ARDs (5/17) than in other forms of NICM (12/100). Conclusions: Extensive and global endomyocardial fibrosis in LV was detected more often in patients with autoimmune rheumatic diseases than in patients with other forms of NICM. The involvement of Purkinje fibres and other endocardial sites in the VT reentry circuits in autoimmune rheumatic diseases may be due to the predominant fibrotic involvement of the endocardium or by direct effects of the autoimmune disease on the conduction system. The detection of extensive or global endomyocardial fibrosis in patients with NICM provides a tool for the early diagnosis of the rare but often severe cardiac involvement in autoimmune rheumatic diseases.

https://dgk.org/kongress_programme/jt2023/aV246.html