An Unusual Case of Takotsubo Cardiomyopathy in Pheochromocytoma

Afana and colleagues1 have presented a case that illustrates the complex interaction between transient takotsubo cardiomyopathy (TC) and pheochromocytoma, which merits discussion.Some authors have accepted the idea that catecholamine surges are the biochemical cause of TC.2 However, others view this explanation as simplistic and have suggested additional considerations, as follows.In most patients, with or without pheochromocytoma, transient endothelial dysfunction probably causes TC. The nebulous underlying mechanism can hardly be assumed to be neurogenic and related to some hypothetical neurologic dysfunction that would also be expected to affect the heart so transiently. In nature, acetylcholine is a local effector of the parasympathetic system. The predisposing factor for TC in pheochromocytoma—sometimes a high catecholamine blood level—is active before and especially during tumor removal, and the risk of TC recurrence will be high if acetylcholine test results are positive. Accordingly, acetylcholine testing after a TC episode is important in cases like that of Afana and colleagues.1 Details are available on how to perform acetylcholine tests safely.4–6The above considerations indicate that much about TC remains to be clarified beyond the simplest explanations of its precipitating causes, especially in association with pheochromocytoma.