Isolated Giant Cell Myocarditis in the Atrium: An Incidental Finding?

Abstract

Giant cell myocarditis (GCM) is an uncommon disorder that affects ventricular myocardium causing severe left ventricular dysfunction and ventricular arrhythmias. We report a case of GCM that only affected the atrium sparing the ventricle.

Eosinophil-derived IL-4 drives progression of myocarditis to inflammatory dilated cardiomyopathy

“…Another study characterized six patients with isolated atrial giant cell myocarditis showing atrial fibrillation, atrial wall thickening, atrial enlargement, and marked atrial inflammation (Larsen et al, 2013). Similar observations were made in case studies of giant cell myocarditis (Ahmad et al, 2006) and eosinophilic myocarditis (Parrillo et al, 1979; Frustaci et al, 1991; Carver et al, 2010). Eosinophilic myocarditis has also been identified as a cause of atrioventricular block in one patient (Tian et al, 2010).…”

“…There was less atrial involvement with patchy LGE located near the annulus. Other studies have also described atrial involvement either alone or together with ventricular inflammation in some cases of eosinophilic myocarditis and giant cell myocarditis (Frustaci et al, 1991; Ahmad et al, 2006; Carver et al, 2010; Tian et al, 2010; Larsen et al, 2013; Xie et al, 2015). This suggests that atrial inflammation and/or fibrosis may also be a feature in some eosinophilic myocarditis patients.…”

Atrial Giant Cell Myocarditis

“…15 More recently, a single case of aGCM was reported at Stanford University, 17 an institution at which 263 resected atrial specimens were evaluated over an 8-year period (2004-2011; 211 adult, 52 pediatric), for an overall aGCM frequency of 0.4% and a frequency among adult cases of 0.5% (Gerald J. Berry, MD, personal communication).…”

“…[15][16][17][18] Herein we describe 6 additional cases of aGCM and characterize their clinical, radiological, and histopathologic features.…”