ECG criteria
- ST-segment elevation — most commonly in V2–V5, may extend to I, aVL, and the inferior leads; the amplitude is variable and does not reliably differentiate Takotsubo from STEMI
- Marked reciprocal ST depression in the inferior leads, typical of anterior STEMI, is generally absent; the spread of ST elevation beyond the supply territory of a single coronary artery supports the diagnosis of Takotsubo, but does not confirm it
- Pathological Q waves and pseudo-Q waves may transiently appear in the acute phase and do not by themselves differentiate Takotsubo from MI; persistent Q waves after the recovery of LV contractility are less typical
- Within the first 24 hours to several days, most commonly in the subacute phase, a deep symmetric T-wave inversion in most chest leads (V2–V6) and often in I and aVL, as well as QTc prolongation, appear or deepen; the timing and severity are variable
- Prolongation of the corrected QT interval (QTc), sometimes pronounced, with a risk of Torsades de Pointes
- A decrease in R-wave amplitude in the precordial leads is possible, but without the formation of a persistent pathological Q wave
- The ECG dynamics do not correspond to a specific coronary territory — the changes are broader than the supply area of a single coronary artery
- The ECG changes regress gradually; T-wave inversion and QTc prolongation often persist for weeks, and sometimes months, not always synchronously with the recovery of LV contractility
What it looks like on ECG
In the acute phase (first hours), ST-segment elevation in the chest leads (predominantly V2–V5) is typical, sometimes extending to I, aVL, and the inferior leads. ST elevation may be diffuse, not limited to the blood supply zone of a single coronary artery — this is an important clue, but it is not absolute, as Takotsubo can also present with localized ST elevation indistinguishable from STEMI on the initial ECG. The amplitude of ST elevation is variable and by itself does not reliably differentiate Takotsubo from STEMI.
Marked reciprocal ST depression in the inferior leads in Takotsubo is less common than in true anterior wall occlusion. However, this is only an indirect guide: the absence of depression and the spread of changes beyond a single territory only support the hypothesis of Takotsubo, but do not replace confirmation by coronary angiography or imaging.
Pathological Q waves and pseudo-Q waves can occur as early as the acute phase of Takotsubo and in some cases are quite frequent; they usually regress as contractility recovers. Therefore, the presence or absence of a Q wave by itself does not reliably differentiate Takotsubo from a completed myocardial infarction.
Within the first 24 hours to several days, more commonly in the subacute phase (after ST elevation subsides), the classic pattern develops — deep, symmetric T-wave inversion in most precordial leads (V2–V6), often involving I and aVL. T-wave inversion is sometimes very pronounced and can persist for weeks, and in some cases months. The timing and severity of these changes are individual and not strictly synchronous.
In parallel, QTc prolongation increases, sometimes significantly (QTc greater than 500 ms), which creates a risk of Torsades de Pointes, especially in the setting of electrolyte disturbances or bradycardia; the maximum QTc prolongation and the deepest T-wave inversion often occur in the subacute phase, but do not necessarily coincide in time with each other.
| Phase | Time | Changes |
|---|---|---|
| Acute | hours | ST elevation in V2–V5 ± I, aVL, inferior leads |
| Subacute | First 24 hours–days | Deep negative T, QTc prolongation (timing variable) |
| Resolution | Weeks–months | Gradual, not always complete normalization of T and QTc |
Persistent pathological reduction in R amplitude, typical of a completed infarction, is absent or minimal in most cases, although a transient reduction in R is possible.
Mechanism
The underlying mechanism is an acute catecholamine surge (emotional or physical stress), which causes transient microvascular spasm, direct catecholamine toxicity to cardiomyocytes, and impaired sympathetic innervation of the myocardium. It is hypothesized that regional differences in adrenergic sensitivity and beta-adrenoreceptor density may contribute to the preferential involvement of the apex, but this is a hypothesis rather than a proven universal mechanism — mid-ventricular, basal, and focal variants of Takotsubo with different distributions of dysfunction also exist. Impairment of contractility usually occurs in the absence of an acute culprit coronary occlusion; concomitant significant CAD is possible and does not exclude Takotsubo per se, provided it does not explain the regional wall motion abnormality pattern. Catecholamine injury, regional myocardial dysfunction, and impaired repolarization ion currents prolong action potential duration and the QT/QTc interval, increasing the risk of Torsades de Pointes; these same processes in the affected myocardium manifest as ST elevation followed by deep T-wave inversion.
Causes
- Acute emotional stress (grief, conflict, fear) — the classic "broken heart syndrome"
- Severe physical stress: trauma, surgery, severe somatic illness
- Acute neurological pathology: subarachnoid hemorrhage, stroke
- Pheochromocytoma and other conditions with catecholamine excess
- Use of catecholamines and certain sympathomimetics
- More common in postmenopausal women
Differential diagnosis
- Anterior STEMI: in Takotsubo, ST elevation is often broader than a single coronary territory, marked reciprocal depression in the inferior leads is less frequent; final differentiation is based on coronary angiography and ventricular imaging (ventriculography, echocardiography, MRI if necessary), since concomitant obstructive CAD does not exclude Takotsubo if it does not explain the dysfunction zone
- Myocarditis: can also present with diffuse ST-T changes not conforming to a coronary territory, differentiated by clinical presentation, serial troponins, and cardiac MRI
- Wellens' syndrome: biphasic or negative T in V2–V3 without ST elevation, indicates critical LAD stenosis rather than Takotsubo
- Subarachnoid hemorrhage itself can cause deep negative T waves and QT prolongation ("cerebral" T waves) — requires neurological context and head CT
- Congenital or acquired long QT syndrome of other etiology: distinguished by acute onset in the setting of stress and dynamics showing normalization
Clinical significance and management
The ECG presentation of Takotsubo at the initial stage is often indistinguishable from STEMI. When STEMI is suspected, the patient is managed according to the acute coronary syndrome emergency algorithm: urgent clinical evaluation, serial troponin, echocardiography; if there is a high probability of acute occlusion, emergency invasive coronary angiography is performed. In selected hemodynamically stable patients with a low probability of acute occlusion after clinical evaluation, coronary CT angiography is possible. Coronary angiography or CT angiography does not confirm the diagnosis of Takotsubo — this requires a combination of data on coronary anatomy, characteristic reversible regional LV wall motion abnormalities (most commonly apical ballooning not matching the supply area of a single artery) on echocardiography/ventriculography, and, if necessary, cardiac MRI to exclude myocarditis and other causes; concomitant obstructive coronary artery disease does not exclude the diagnosis of Takotsubo per se. QTc prolongation requires rhythm monitoring due to the risk of Torsades de Pointes, correction of electrolytes (potassium, magnesium), and caution with QT-prolonging drugs. Acute phase complications include cardiogenic shock, left ventricular outflow tract obstruction, LV cavity thrombosis, and life-threatening arrhythmias, therefore patients are monitored in settings equipped for monitoring and emergency care. The clinical course is typically reversible: LV function recovers within weeks, whereas ECG changes regress gradually and may persist longer than the recovery of contractility, sometimes for weeks or months.
Common interpretation errors
- Ruling out ACS solely based on the "diffuse" nature of ST elevation — Takotsubo can also mimic localized STEMI
- Ignoring QTc prolongation and the risk of Torsades de Pointes in the subacute phase
- Attempting to diagnose Takotsubo based on a single ECG without ventricular imaging and exclusion of acute coronary occlusion
- Assuming that the absolute absence of any obstructive coronary artery disease is a mandatory criterion for Takotsubo, although concomitant CAD does not exclude it
- Underestimating that deep negative T waves and prolonged QTc can persist for weeks and months and be mistakenly interpreted as a sign of ongoing ischemia
- Failure to consider an alternative cause of diffuse T and QT changes (subarachnoid hemorrhage, myocarditis)
1. Which ECG finding is most typical for the subacute phase of takotsubo cardiomyopathy?
The subacute phase of takotsubo is characterized by deep negative T waves in the chest leads and marked QTc prolongation; a pathological Q wave is not mandatory and does not define the diagnosis.
2. Which sign helps differentiate takotsubo from coronary artery occlusion during ST elevation, although it is not absolute?
In takotsubo, ECG changes often exceed the supply area of a single coronary artery, whereas STEMI typically corresponds to a specific territory, though this distinction is not absolute and requires confirmation by coronary angiography and imaging.
3. Which complication of the acute phase of takotsubo is associated with QTc prolongation?
Marked QTc prolongation in the subacute phase of takotsubo carries a risk of polymorphic ventricular tachycardia (torsades de pointes).
Frequently asked questions
How to differentiate takotsubo from anterior STEMI on ECG?
At the initial stage, reliable differentiation is not possible—ST elevation can be identical. Clues favoring takotsubo include broader ST elevation extending beyond a single coronary artery territory and less pronounced reciprocal depression in the inferior leads, but the definitive diagnosis is established following coronary angiography and ventricular imaging (echocardiography, ventriculography, and MRI if necessary).
Is takotsubo cardiomyopathy dangerous?
Yes, the acute phase can be complicated by cardiogenic shock, life-threatening arrhythmias associated with prolonged QT, left ventricular mural thrombosis, and left ventricular outflow tract obstruction. However, cardiac function recovers in the majority of patients within weeks.
Does the ECG normalize after takotsubo?
A gradual resolution of ST elevation is typical, followed by T-wave inversion and QTc prolongation, but complete normalization may take weeks or months and does not always coincide temporally with the recovery of left ventricular contractility on echocardiography.
Why is the QT interval so markedly prolonged in takotsubo?
Catecholaminergic injury, regional myocardial dysfunction, and impaired repolarization ion currents prolong action potential duration and the QT/QTc interval. This creates a risk of torsades de pointes, especially in the setting of electrolyte disturbances.
Is coronary angiography necessary when takotsubo is suspected?
When STEMI is suspected, the patient is managed according to the emergency ACS protocol, and urgent invasive coronary angiography is performed if the probability of acute occlusion is high; CT coronary angiography is an option for selected stable patients. The diagnosis of takotsubo is confirmed by a combination of coronary anatomy findings, LV imaging, and cardiac MRI when necessary, rather than by coronary angiography alone.
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Related terms
More in the «Channelopathies and Cardiomyopathies» section
Sources
- Goldberger's Clinical Electrocardiography, latest edition
- Hampton. The ECG in Practice
- Surawicz, Knilans. Chou's Electrocardiography in Clinical Practice
- ESC Guidelines for the management of acute coronary syndromes, 2023
Educational material for medical students and physicians. Does not replace clinical guidelines and physical examination; the ECG must always be interpreted in conjunction with the clinical picture.