Inflammatory-mediated atrial cardiomyopathy diagnosed using multimodality imaging and successfully treated with prednisolone: a case report

Abstract

Background: Atrial fibrillation is a common cardiac arrhythmia and often develops secondary to structural cardiac changes. Both the occurrence of atrial fibrillation and/or structural changes of the heart may lead to development of atrial cardiomyopathy and heart failure (HF). However, isolated atrial cardiomyopathy caused by focal atrial thickening is a rare condition, previously only described in case reports as a result of different aetiologies all linked to inflammation.

Case summary: A patient with inflammatory-mediated atrial cardiomyopathy causing atrial fibrillation and acute decompensated HF presented as isolated left atrial wall thickening on transoesophageal echocardiography. The diagnosis was confirmed using multimodality imaging with transthoracic and transoesophageal echocardiography, cardiac magnetic resonance imaging, positron emissions tomography/computer tomography scanning and intracardiac echocardiography-guided endomyocardial biopsy. Despite no specific histological aetiology, the observed atrial cardiomyopathy might be associated with type 1 diabetes mellitus. The patient in the present case was successfully treated with prednisolone.

Discussion: Diabetes mellitus is an important risk factor for developing atrial fibrillation and diabetic cardiomyopathy, due to reduced levels of anti-inflammatory and increased levels of proinflammatory cytokines causing cardiac inflammatory structural remodelling. The regression of the atrial thickening might be due to prednisolone's anti-inflammatory effects and thereby ability to suppress atrial remodelling and reduce the occurrence of atrial fibrillation. However, the effect of prednisolone might only affect the non-manifested inflammatory-mediated atrial remodelling. Due to the rare occurrence of isolated atrial cardiomyopathy a multiple imaging approach during the diagnostic process and follow-ups are essential to determine the aetiology and effect of the treatment.

Keywords: Atrial fibrillation; Atrial remodelling; Atrial wall thickening; Case report; Diabetes mellitus; Isolated atrial myopathy; Left atrial enlargement.

Figure 1

Transoesophageal echocardiography and left atrial strain before and after prednisolone treatment. (A) TOE and left atrial strain at second readmission. (B) TOE and a’ velocity following prednisolone treatment at two-months follow-up. (C) TOE and left atrial strain at three-months follow-up after ended prednisolone treatment. TOE, Transoesophageal echocardiography.

Figure 2

Cardiac magnetic resonance imaging before prednisolone treatment. Cardiac magnetic resonance imaging confirming left atrium dilatation with extensive wall thickening. Mapping sequences revealed fibrosis suggestive of pathological inflammatory activity of the left atrium. (A) Cine sequence four-chamber view. (B) Cine sequence short axis view. (C) Cine sequence three chamber view. (D) T2 mapping four-chamber view. (E) T1 mapping short axis view. (F) T2 mapping four-chamber view with left atrial region of interest. (G) T1 mapping short axis view with left atrial region of interest.

Figure 3

Positron emissions tomography/computed tomography before and after prednisolone treatment. (A) PET/CT before prednisolone treatment. (B) PET/CT after prednisolone administration at two-months follow-up. PET/CT, positron emissions tomography/computed tomography.

Figure 4

Endocardial biopsy before prednisolone treatment. Endocardial left atrial biopsy demonstrating extensive chronic inflammation dominated by B-lymphocytes. Haematoxylin Eosin stains as background. CD20, B-lymphocytes; CD3, T-lymphocytes; MUM1, plasma cells; CD68, macrophages.