Reversible dilated cardiomyopathy associated with glucagonoma

Area of Science:

• Cardiology
• Endocrinology
• Oncology

Background:

• Dilated cardiomyopathy is a serious heart condition often with unknown causes.
• Glucagonoma, a rare pancreatic neuroendocrine tumor, primarily causes skin rashes and metabolic disturbances.
• A direct association between glucagonoma and dilated cardiomyopathy has not been previously reported.

Purpose of the Study:

• To describe a unique case of dilated cardiomyopathy associated with glucagonoma.
• To investigate the potential causal link between glucagon excess and cardiac dysfunction.
• To highlight glucagonoma in the differential diagnosis of unexplained cardiomyopathy.

Main Methods:

• Case report of a 54-year-old woman presenting with tachycardia and congestive heart failure.
• Echocardiography revealed severely reduced ejection fraction (15%) consistent with dilated cardiomyopathy.
• Diagnostic workup included coronary angiography, endomyocardial biopsy, and imaging for glucagonoma, alongside serum glucagon level measurement.

Main Results:

• The patient developed characteristic necrolytic migratory erythema, and pancreatic imaging identified a mass with elevated serum glucagon.
• Cardiomyopathy and tachycardia persisted despite standard medical therapy (beta-blockers).
• Tumor resection led to normalization of heart rate and subsequent recovery of cardiac size and function.

Conclusions:

• This case suggests glucagonoma can be a rare cause of dilated cardiomyopathy and tachycardia.
• Elevated glucagon levels may directly impact myocardial function, potentially via increased cyclic AMP.
• Glucagonoma should be considered in the differential diagnosis for patients presenting with unexplained tachycardia and dilated cardiomyopathy.