Imipramine-provoked paradoxical pheochromocytoma crisis: a case of cardiogenic shock.

The dramatic presentation of pheochromocytoma in crisis is uncommon and is classically associated with a state of hemodynamic and sympathetic hyperactivity. The case of a 35-year-old man with an occult pheochromocytoma presenting with hypotension and cardiogenic shock shortly after beginning imipramine therapy is presented. Retrospectively, there was a history of emergency department, inpatient, and outpatient evaluation of symptoms likely to be related to an occult pheochromocytoma. He presented with hypotension refractory to fluids and inotropes and in severe respiratory distress. The early differential diagnosis was extensive including acute myocardial infarction, pneumonia with sepsis, and toxic ingestion. Shortly after admission the patient's occult pheochromocytoma was discovered and subsequently specific therapy was initiated. The patient's symptoms resolved after surgical resection of the tumor, and he was ultimately discharged without signs of congestive heart failure. The clinical pathophysiology of cardiomyopathy secondary to pheochromocytoma, and possible mechanisms of pharmacological interactions with tricyclic antidepressants are discussed.