Dobutamina induz Takotsubo ou Takotsubo é um Ecoestresse naturalmente induzido?

Takotsubo cardiomyopathy (left ventricular ballooning syndrome) induced during dobutamine stress echocardiography
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A standard dobutamine/atropine protocol had been used.

The patient developed central crushing chest pain, marked ST elevation, transient slowing of heart rate and left ventricular apical ballooning. She was admitted to the coronary care unit and received thrombolysis. Echocardiography showed no mitral regurgitation, normal pulmonary artery systolic pressure and no intraventricular gradient. Immediate troponin T was significantly raised and peaked at 6 h. The patient underwent coronary angiography the next day. This showed systolic left ventricular apical ballooning and no coronary lesions or vasospasm. A further contrast echo 2 weeks later showed complete resolution of the wall motion abnormalities.
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Quem faz Ecoestresse com Dobutamina cansa de ver gradiente intraventricular no meio do exame, principalmente com doses acima de 30mg/kg. A foto do ventrículo no momento do gradiente é um Takotsubo com detalhes!
Seria o gradiente elevado o causador da dilatação apical? Afinal, havendo gradiente haverá sempre um esforço muscular anormal.