Takotsubo or stress cardiomyopathy: role of nuclear cardiology using (123)I-MIBG.

Takotsubo cardiomyopathy, also known as broken heart syndrome or stress cardiomyopathy, is a very interesting syndrome of acute transient left ventricular dysfunction, usually following significant emotional stress. It was first described in Japan nearly two decades ago and many aspects of its pathogenesis still remain poorly understood. The incidence of out-of-hospital sudden death related to Takotsubo is currently unknown. Excess catecholamines following stress seem to trigger Takotsubo and play an important role. The clinical presentation resembles acute myocardial infarction, including chest tightness and/or dyspnea, ECG changes and elevated cardiac enzymes. However, in contrast to a typical acute myocardial infarction, no significant coronary lesions or thrombi are found on coronary angiography. Differentiating Takotsubo from acute myocardial infarction is important to avoid the unnecessary risks of thrombolytic therapy. Typically, left ventriculography shows marked abnormalities with akinesia in the mid-distal anterior wall and apex (occasionally involving other heart regions), giving a balloon shape to the left ventricle. The name Takotsubo originates from the shape of the left ventricle, which resembles a Japanese octopus-trapping pot. Hospital mortality is low but death can be caused by severe acute heart failure and/or ventricular arrhythmias. Typically, a stressful life event is reported preceding the acute symptoms. Takotsubo is most common in menopausal women although young individuals, including men, can also be affected. The autonomic nervous system has a defined role in the process. In this article, we will review the role of imaging the heart using (123)I-meta-iodobenzylguanidine, a radioactive marker allowing mapping of the autonomic nervous system of the heart, in cases of suspected Takotsubo.