Isolated giant cell myocarditis in the atrium: an incidental finding?

Area of Science:

• Cardiology
• Pathology
• Immunology

Background:

• Giant cell myocarditis (GCM) is a rare, aggressive cardiac inflammatory disease.
• It typically involves the ventricular myocardium, leading to significant left ventricular dysfunction and arrhythmias.
• Diagnosis often relies on endomyocardial biopsy, though challenges exist due to patchy inflammation.

Observation:

• This report details an unusual case of GCM.
• The patient presented with symptoms not typical of standard GCM presentation.
• Diagnostic imaging and biopsy revealed inflammation confined exclusively to the atrial myocardium.

Findings:

• The pathological findings confirmed giant cell myocarditis.
• Crucially, the ventricular myocardium remained unaffected, a distinct deviation from established GCM patterns.
• This localized atrial GCM resulted in specific clinical manifestations distinct from typical ventricular involvement.

Implications:

• This case expands the known clinical spectrum of giant cell myocarditis.
• It highlights the possibility of isolated atrial GCM, challenging the traditional understanding of its typical ventricular predilection.
• Further research into the specific triggers and pathogenic mechanisms of atrial-limited GCM is warranted.