title: Insulinoma presenting with cardiac arrest and cardiomyopathy.
abstract: A 33-year-old woman presented with ventricular fibrillation cardiac arrest and was found to have a blood glucose of 1.83 mmol/L. Cardiac catheterisation revealed a dilated left ventricle with an ejection fraction (EF) of 26% and angiographically normal coronary arteries. Continuous dextrose infusion was required to treat hypoglycaemia, which prompted consideration of insulinoma as a possible cause for her cardiomyopathy. Whipple's triad was demonstrated; a 72 h fast provided biochemical evidence of insulinoma, and imaging localised a tumour in her pancreas. The tumour was resected and pathology confirmed insulinoma; pancreaticoduodenectomy cured her hypoglycaemia. No alternate cause of cardiomyopathy was found and 4 months after surgery her EF improved to 41%. High insulin levels can close cardiac K(ATP) channels associated with dilated cardiomyopathy; the catecholamine surge from hypoglycaemia may also contribute to ventricular remodelling. Hypoglycaemia can cause QT segment prolongation, and may have precipitated fibrillation in this patient's arrhythmia-prone myocardium.
authors.affiliation: Internal Medicine Residency Program, University of Washington, Seattle, Washington, USA.
authors.forename: Arthi
authors.initials: A
authors.lastname: Thirumalai
authors.forename: Ximena A
authors.initials: XA
authors.lastname: Levander
authors.forename: Somnath
authors.initials: S
authors.lastname: Mookherjee
authors.forename: Andrew A
authors.initials: AA
authors.lastname: White
mesh_terms: D000328:Adult; D009202:Cardiomyopathies / Q000209:etiology*; D004452:Echocardiography; D005260:Female; D006323:Heart Arrest / Q000209:etiology*; D006801:Humans; D007003:Hypoglycemia / Q000209:etiology; D007340:Insulinoma / Q000150:complications* / Q000000981:diagnostic imaging; D010190:Pancreatic Neoplasms / Q000150:complications* / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed