Endocrine Abstracts

Introduction: Cardiomyopathy as the initial presentation of phaeochromocytoma (PCA) is uncommon. Diagnostic workup and perioperative management may be challenging within this context. We report three cases of PCA presenting with cardiomyopathy to illustrate the pitfalls in diagnosis and management. None of the patients had typical adrenergic symptoms of catecholamine excess and all patients were well established on beta-blockers on presentation. All three patients had an adrenalectomy and a PCA was confirmed on histology.

Cases: Patient A: A normotensive 56-year-old male with dilated cardiomyopathy, was found to have an incidental longstanding right adrenal nodule. Plasma and urine metadrenaline levels were raised during decompensated heart failure and improved with treatment. However, a subsequent increase in metadrenaline levels was noted despite clinical and echocardiographic improvement of cardiac function. MIBG and Octreotide scans were both negative but CT of the right adrenal with wash out studies showed indeterminate characteristics. Patient B: A 66-year-old male was referred with a right adrenal mass. Previous investigations revealed severe left ventricular impairment and non-flow limiting coronary disease. Plasma and urine metadrenalines were raised and asymmetrical adrenal uptake was noted on an MIBG scan. Patient C: A 61-year-old female with type 1 Neurofibromatosis presented with Takotsubo cardiomyopathy. Fractionated metadrenaline levels were raised and a MIBG avid left adrenal lesion, corresponding to a left adrenal mass on CT scan, was found.

Conclusions: Interpretation of fractionated metadrenaline levels in the context of established cardiomyopathy is difficult as cardiac failure of any aetiology generates an adrenergic response. Screening all patients with idiopathic cardiomyopathy for catecholamine excess is highly likely to generate false positive results. However, a high index of suspicion should prompt further investigations of patients with idiopathic cardiomyopathy for occult an PCA. Peer reviewed guidelines are required to guide the investigation and management of suspected catecholamine-induced cardiomyopathy.