Undiagnosed Insulinoma in a Young Patient With Idiopathic Dilated Cardiomyopathy: A Case Report

Insulinomas are rare pancreatic tumors that present with symptoms of hypoglycemia secondary to unregulated high levels of insulin. Literature has described that recurrent hypoglycemic events induce a sympathetic drive that could compromise cardiac function. Tumor resection eliminates the hypoglycemia source, halting the cycle of sympathetic overdrive and improving cardiac function. We present the case of a 43-year-old patient who was hospitalized after a recent gastric bypass for recurrent episodes of confusion, mumbling, night terrors, and low glucose levels. She also had a chronic diagnosis of idiopathic dilated cardiomyopathy and heart failure with an ejection fraction of 30%. Imaging and laboratory studies demonstrated the presence of insulinoma. She underwent tumor resection with improvement in her exercise tolerance. Her ejection fraction improved from 30% to 35-40% eight months post-resection. This case is intended to review current data on the possible association between insulinomas and heart disease. To the best of our knowledge, our report stands out as one of the few case studies available that explores this potential association. It is crucial to recognize that tumor resection can significantly enhance cardiac function, making it imperative to thoroughly investigate the diverse cardiovascular effects linked to insulinomas.