Case presentation

Dr. Vicidomini, Dr. Zanobetti, Dr. Innocenti: A 69-year-old Caucasian woman was admitted to our emergency department (ED) for an acute and initial episode of substernal chest pain radiating to the left arm, which had lasted about 1 h, associated with dyspnea and diaphoresis. She had a past medical history of depression and first stage primary biliary cirrhosis. She was taking chronic low-dose sotalol therapy (80 mg PO bid) for a prior episode of supraventricular tachycardia. She had an otherwise normal heart, and was without cardiovascular risk factors.

At admission, she denied any recent emotional or stressful event. The first EKG recorded 10 min after the ED admission showed mild ST-segment depression in the precordial leads V5 and V6 (Fig. 1), without significant changes in the inferior, posterior and right precordial leads.

Fig. 1
figure 1

First ECG showing mild ST depression in the precordial leads V5–V6

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The first blood sample analysis exhibited normal values of Troponin-I (cTn-I: 0.10 μg/L, normal range: 0–0.15 μg/L) and CK-MB (1.1 ng/ml, normal range: 0.5–3.6 ng/ml). The patient, fully asymptomatic, was admitted to our intensive observation unit.

Based on our protocol, a second blood chemistry control was performed 6 h after the initial results. An elevated cTn-I value of 3.31 μg/L with normal CK-MB value (1.0 ng/ml) was observed. The EKG registered at the same time as the laboratory blood tests showed T-wave inversion in the precordial leads from V1 to V4 (Fig. 2), not present in the first tracing,and a small QT dispersion with a QT interval a bit longer than previous EKG. Trans-thoracic echocardiography showed normal left ventricular internal dimensions; the segmental wall motion analysis revealed akinesis of the basal anterior wall and the entire interventricular septum associated with hypokinesis of the inferior wall basal segments. Postero-lateral basal segments and all mid-ventricular and apical segments appeared hyperkinetic.

Fig. 2
figure 2

Second ECG showing T-wave inversion in the precordial leads V1–V4

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Preliminary diagnosis

Dr. Zanobetti, Dr. Conti, Dr. Pini: Based on the initial presentation, EKG abnormalities and a positive marker of myocardial necrosis, an acute coronary syndrome, myocarditis, or an atypical presentation of Tako-Tsubo syndrome were considered.

None of the serial EKGs exhibited abnormalities characteristic of an acute coronary syndrome, and there was a mismatch between the limited extension of EKG abnormalities and the diffuse wall motion abnormalities in the echocardiographic examination. This mismatch can support the diagnosis of myocarditid, especially in the presence of limited abnormalities of myocardial specific enzymes. However, all indices of inflammation (C-Reactive Protein, leucocytes, erythrocyte sedimentation rate) were in the normal range. The limited EKG abnormalities associated with clear LV wall motion abnormalities can support the diagnosis of Tako-Tsubo syndrome, but the distribution of the wall motion abnormalities was clearly unusual because all the apical segments were unaffected. Thus, the treatment with ACE inhibitors, Ca-blocking agents and Clopidogrel was started, and a coronary angiography was scheduled for the next day.

24 h after the admission, the patient underwent diagnostic coronary angiography that showed absence of significant coronary stenosis. The left ventriculography showed a normal left ventricular cavity without asynergic areas.

Definitive diagnosis

Dr. Conti, Dr. Innocenti: On the third day, the laboratory tests showed a cTn-I level of 0.64 μg/L. The EKG showed a complete resolution of the previous alterations; similarly, the echocardiogram revealed restored normal motion of all the left ventricular segments. cTn-I level at discharge was 0.11 μg/L. The patient was discharged fully asymptomatic 4 days after admission, with the indication to continue the pharmacological treatment started in the ED; the final diagnosis was atypical Tako-Tsubo syndrome.

Discussion

Dr. Zanobetti, Dr. Vicidomini, Dr. Pini: Tako-Tsubo cardiomyopathy, also called stress-induced cardiomyopathy, is a clinical entity first described in Japan [1]. It is characterized by reversible left ventricular apical wall motion abnormalities with typical ischemic type chest pain, electrocardiographic changes, and relatively minor elevation of myocardial enzymes, without angiographic evidence of epicardial coronary artery stenosis. The condition is confined almost exclusively to elderly women, and is often precipitated by a severe psychological or physical stress, but its pathological basis remains uncertain [2]. The electrocardiographic changes during chest pain are often similar to those found in patients with acute anterior ST-segment elevation myocardial infarction (STEMI) [3]. On the other hand, some cases have been described with non-specific repolarization changes on the admission EKG [4]. In our case, the EKG at the admission showed ST-segment depression and T-wave inversion in the precordial leads associated with an increased cTn-I level at 6 h. Moreover, as occasionally described [5, 6], the second EKG showed an abnormal QT interval not present in the prior tracing.

A careful echocardiographic wall motion analysis is a useful tool for a definite diagnosis. In typical cases, the transthoracic echocardiogram shows akinesia of mid-apical segments with systolic ballooning of the left ventricular apex and contemporary hyperkinetic motion of the basal segments, confirmed by ventriculography. In our case the ventriculography did not show asynergic areas, probably because it was performed after 24 h, when wall motion abnormalities had already disappeared.

Based on anatomic location, four different types of Tako-Tsubo are described in the literature. The “classic type”, which is the most commonly reported, is described as apical ballooning or Tako-Tsubo type. The “second type” is the reverse type with hyperdynamic apex and akinesia of left ventricular basal segments (reverse Tako-Tsubo or reverse apical ballooning type). This type is only rarely described in the literature [7–11]. The “third type” involves the mid left ventricular wall, sparing the base and the apex; it is also called “mid ventricular type” [12–14]. The “fourth type” is characterized by a localized wall motion abnormality affecting a segment of the left ventricular wall, usually the anterior wall [15–18].

In our case, echocardiographic images showed akinesis of the basal anterior wall, and of the entire interventricular septum associated with hypokinesis of the basal segments of the inferior wall (Table 1) [14, 19–33]. Our case combined the anatomic abnormalities previously classified as type two, three and four.

Table 1 Clinical, electrocardiographic and echocardiographic findings previously described in patients with “inverted Tako-Tsubo”.
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Although the precise mechanism remains unclear, and further studies are necessary to clarify the clinical and pathophysiological features of this syndrome, we would emphasize the importance of promptly thinking of the Tako-Tsubo syndrome. In patients with predisposing clinical factors (e.g., female sex, advanced aged, recent stressful events, typical chest pain, EKG signs of acute ischemia) the combined role of electrocardiogram and transthoracic echocardiography is essential for isolating and identifying possible regional wall motion abnormalities discordant from those predictable at EKG examination, thus suggesting an atypical Tako-Tsubo syndrome with a normal coronary tree.