**4. Anatomical variants**

present with acute chest pain, and demonstrates the typical biomarker profile (release of cardiac troponin and creatine kinase) and/or electrocardiographic abnormalities suggesting significant coronary stenosis. Interestingly, the distinguishing factor in Takotsubo syndrome is the absence of an occlusive coronary vascular disease, which correlates with these changes [8]. Although, the pathophysiology of this disorder remains unclear, recent hypotheses have suggested a form of acute catecholaminergic myocardial stunning to explain the pattern of temporary LV dysfunction and regional wall-motion abnormality commonly seen at the time

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

• Transient regional wall-motion abnormalities of LV or RV myocardium which are frequently, but not always,

• The absence of culprit atherosclerotic coronary artery disease including acute plaque rupture, thrombus formation, and coronary dissection or other pathological conditions to explain the pattern of temporary LV dysfunction

• New and reversible electrocardiography (ECG) abnormalities (ST-segment elevation, ST depression, LBBB,<sup>b</sup>

• Positive but relatively small elevation in cardiac troponin measured with a conventional assay (i.e. disparity

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

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 wall-

extend beyond a single epicardial vascular distribution, and

preceded by a stressful trigger (emotional or physical).

observed (e.g. hypertrophic cardiomyopathy, viral myocarditis).

often result in circumferential dysfunction of the ventricular segments involved.

T-wave inversion, and/or QTc prolongation) during the acute phase (3 months).

between the troponin level and the amount of dysfunctional myocardium present).c • Recovery of ventricular systolic function on cardiac imaging at follow-up (3–6 months).d

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

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

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

• Significantly elevated serum natriuretic peptide (BNP or NT-proBNP) during the acute phase.

• The regional wall-motion abnormalities usuallya

of presentation [9].

218 Interventional Cardiology

**2. Definition**

stresses.

a

b

c

of LV function.

motion abnormality observed.

A study describing the varying morphological presentations of the left ventricle in patients diagnosed with the Takotsubo syndrome has led to the identification of at least four major anatomical variants [12, 13]. The classical pattern defined by an apical ballooning of the left ventricle at end-systole is present in at least 50–80% of the cases. The inverted Takotsubo (basal) variant with a predominantly hypokinetic circumferential base; the mid left ventricular variant with a hypokinetic circumferential mid ventricle; and the focal variant constitute other forms of presentation. Rarer variations include cases with a pronounced dysfunction of the biventricular apex and those with an isolated right ventricular involvement [14–16].
