**2. Definition**

The Takotsubo syndrome is an acute and usually reversible form of heart failure, precipitated by physical and/or emotional stresses or in some cases without any evident preceding trigger. In recent years, various institutions and working groups such as the Mayo Clinic, the Gothenburg group, the Japanese Circulation Society and the Takotsubo Italian Network have proposed their diagnostic criteria to better define this disease; however, in 2015, the Heart Failure Association for the European Society of Cardiology (HFA) outlined its conclusive version. This has been outlined in **Table 1** [8, 10]. A significant feature of this criterion is the inclusion of pheochromocytoma as a trigger for this syndrome. Patients diagnosed with this disorder could suffer from an acute Takotsubo syndrome in the event of a catecholamine storm, analogous to the response incited by other emotional or physical stresses.


a Acute, reversible dysfunction of a single coronary territory has been reported.

b Left bundle branch block may be permanent after Takotsubo syndrome, but should also alert clinicians to exclude other cardiomyopathies. T-wave changes and QTc prolongation may take many weeks to months to normalise after recovery of LV function.

c Troponin-negative cases have been reported, but are atypical.

dSmall apical infarcts have been reported. Bystander sub-endocardial infarcts have been reported, involving a small proportion of the acutely dysfunctional myocardium. These infarcts are insufficient to explain the acute regional wallmotion abnormality observed.

**Table 1.** Heart Failure Association diagnostic criteria for Takotsubo syndrome [10].
