Takotsubo’s syndrome

ECG 1: This tracing shows a sinus rhythm, a narrow QRS, an isolated Q-wave in lead II (minimal in aVF), a moderate depression in leads I, aVL and negative T-waves from V2 to V6 and in leads I and aVL; the negative T-waves are of high amplitude; the QT interval is prolonged (500 ms, QTc to 464 ms); isolated ventricular extrasystole;

Comments: This patient presents a Takotsubo’s syndrome, evoked in conjunction with clinical context (postmenopausal woman, chest pain occurring as a result of a significant emotional stress, electrocardiographic pattern of diffuse negative T-waves with QT interval prolongation, slight increase in troponin in discordance with major ventricular kinetic disorders). The ultrasound and angiographic pattern was highly suggestive of Takotsubo (segmental kinetic disorders, apical ballooning pattern) with coronary angiography failing to show any coronary thrombosis or signs of plaque rupture. Clinical and ultrasound evolution was favorable within 6 weeks with normalization of the ultrasound.

Takotsubo’s syndrome, initially described by Sato in Japan in 1990, corresponds to a transient catecholaminergic acute cardiomyopathy, which predominantly affects postmenopausal women in a setting of intense emotional or physical stress (a notification of death, aggression, natural disaster, highway accidents, massive drug intake, etc.). The etymology of the term Takotsubo stems from the Japanese Tako = octopus and Tsubo = pot, the morphology exhibited by the left ventricle in systole at ventriculography resembling an octopus trap used by Japanese fishermen. The clinical and electrocardiographic presentation is very similar to that of an acute coronary syndrome (ACS) although this syndrome is characterized by the absence of angiographically significant coronary stenosis. The most common clinical presentation is a typical retrosternal pain, associated or not with dyspnea. Nonspecific accompanying signs: palpitations, lipothymia, syncope, and more rarely, cardiogenic shock or inaugural cardiac arrest.

In order to affirm the diagnosis of Takotsubo, the following criteria must all be fulfilled: 1) transient pattern of hypokinesia, dyskinesia, or apical akinesia, of the left ventricle with spontaneously favorable evolution and normalization of cardiac kinetics within a few weeks; a trigger (stress) is common but not always present; 2) absence of obstructive coronary disease or angiographic signs of acute plaque rupture; 3) electrocardiographic abnormalities (recent onset of ST-segment elevation and/or T-wave inversion) or moderate rise in troponin; 4) absence of acute viral myocarditis, pheochromocytoma or acute cerebrovascular disease.

Several pathophysiological mechanisms have been suggested to explain the transient disorders of segmental kinetics:

1. exaggerated stimulation of the sympathetic nervous system during intense emotional or physical stress causing an increase in the concentration of plasma catecholamines with a toxic effect on cardiac muscle. An increased density of adrenergic receptors at the apical segments would explain the apical localization of the kinetic disorders;
2. presence of a microvascular coronary spasm secondary to a marked hyperadrenergic state;
3. the hypothesis of an aborted myocardial infarction, even if the impaired myocardial territory is weakly compatible, since not corresponding to a zone supplied by a single coronary artery;
4. an endothelial dysfunction due to postmenopausal estrogen deficiency is proposed to explain the female predominance of the syndrome. The preferential occurrence in women could also be explained by a potentiating synergistic role of catecholamines and sex hormones.

The electrocardiogram reveals widespread, dynamic, non-specific abnormalities with the presence of an elevation and/or negative T-waves. A moderate increase in troponin is frequently found, although in lesser proportions than in an ACS (discrepancy between the severity of ultrasound muscle damage and the limited increase in the value of this biomarker). Ultrasound and angiography show the characteristic pattern of apical ballooning in systole with compensating hyperkinesia of the basal segments. Coronary angiography is normal.

Takotsubo’s syndrome remains a diagnosis of exclusion. Once the hypothesis of an ACS has been eliminated, therapeutic management includes the introduction of beta-blocking therapy (to block excess catecholamines and limit the hypercontractility of the basal segments) and angiotensin conversion enzyme inhibitors (to promote inverse remodeling) for a period of three to six months or until complete recovery of segmental contractility.

The prognosis of Takotsubo is excellent once the acute phase has passed, with a limited recurrence rate and a total regression of angiographic signs in a large majority of patients.

Take-home message: The electrocardiographic pattern of Takotsubo is dynamic and varies according to the delay in onset of symptoms with significant interindividual variations. It is very difficult from an ECG to differentiate between Takotsubo and an anterior acute coronary syndrome due to occlusion of the medial or distal LAD; performing a coronary angiography is essential to confirm the diagnosis.