Respiratory insufficiency from myasthenia gravis and polymyositis due to malignant thymoma triggering Takotsubo syndrome.

BACKGROUND

Takotsubo syndrome (TTS) is a non-ischaemic cardiomyopathy with sudden but transient systolic dysfunction. TTS mimics myocardial infarction clinically, chemically, and electrocardiographically but echocardiography typically shows apical ballooning and coronary angiography is normal. TTS has not been reported in a patient with myasthenia gravis (MG) and polymyositis due to a malignant thymoma.

CASE REPORT

Two weeks prior to admission, a 76-year-old female developed dysarthria, chronic coughing and disabling myalgias of the entire musculature. Since there was hyper-CKemia and elevated troponin, myocardial infarction was suspected. During swallowing of the antithrombotic medication on admission, she experienced apnoea, requiring cardio-pulmonary resuscitation with intubation and mechanical ventilation. Further diagnostic work-up precluded coronary heart disease but revealed TTS. Upon neurologic work-up, MG and polymyositis were diagnosed but the response to cholinergic drugs and plasmapheresis was poor. TTS was attributed to stress and anxiety from MG-associated respiratory insufficiency. The further course was complicated by recurrent supraventricular bradyarrhythmias and respiratory insufficiency. Upon thoracic CT a thymoma was suspected. Two months after admission, the mediastinal tumour was resected and malignant thymoma WHO BII infiltrating the mediastinum (modified Masaoka-Koga II/2) was diagnosed.

CONCLUSIONS

This case shows that TTS may be triggered by stress from respiratory insufficiency during a myasthenic crisis, MG may be associated with polymyositis, cholinergic medication may trigger bradyarrhythmias, and cholinergic drugs and plasmapheresis may exhibit a poor effect if malignant thymoma and polymyositis are present.