Chest pain, ECG changes and elevated cardiac biomarkers. Everything looks like an infarction, but angiography shows no significant coronary obstruction. This is the classic scenario of Takotsubo syndrome, also known as broken heart syndrome.
In this post, you will learn:
- The main electrocardiographic changes in Takotsubo
- The typical time course of the ECG
- How to distinguish it from ACS, especially anterior infarction
- And which ECG findings are associated with higher clinical risk
What Is Takotsubo Syndrome?
Takotsubo syndrome is a form of transient cardiomyopathy triggered by intense physical or emotional stress, characterized by contractile dysfunction usually involving the apex and mid segments of the left ventricle. It mainly affects postmenopausal women and presents as an acute coronary syndrome (ACS), but without obstructive coronary lesions.
Most Common Electrocardiographic Changes
ECG changes are present in most cases, and the main findings are:
- ST elevation (≈ 40–50%)
- T-wave inversion (≈ 40%)
- QTc prolongation
- Transient Q waves, low voltage and even J waves in some cases
- ST depression is uncommon (≈ 8%)
Typical Time Course in 4 Stages
The ECG in Takotsubo follows a very characteristic evolution:
| Stage | ECG changes | Time from symptom onset |
|---|---|---|
| 1 | ST elevation | Immediate to a few hours |
| 2 | ST normalization + onset of T-wave inversion | 1 to 3 days |
| 3 | Deep inverted T waves or transition | 2 to 6 days |
| 4 | Persistence or normalization of T waves | Weeks to months |
This timeline helps distinguish it from the ECG evolution of acute myocardial infarction.
How to Distinguish Takotsubo from Anterior Infarction?
Despite the clinical and electrocardiographic similarity, some findings favor Takotsubo:
| Criterion | Finding suggesting Takotsubo |
|---|---|
| ST in V1 | Absent or minimal |
| ST in II greater than in III | Common |
| ST depression in aVR (> 0.5 mm) | Strongly suggestive |
| QTc > 500 ms | More common and more prolonged |
| Q wave | Rare and transient |
| No inferior reciprocal depression | Helps distinguish it from extensive MI |
👉 Studies show that a ratio of summed ST in V4–V6 to summed ST in V1–V3 > 1 favors Takotsubo
👉 The Kosuge formula: (3 × ST in V2) + ST in V3 + (2 × ST in V5) < 11.5 mm → high sensitivity and specificity
However, despite these differences, clinical and electrocardiographic findings overlap, and coronary angiography is indicated to exclude the diagnosis of MI.
Other Electrocardiographic Findings
In addition to repolarization changes, some rarer findings may occur:
- QRS fragmentation
- J wave
- Transient reduction in QRS voltage
- Left bundle branch block (less common)
Arrhythmias such as atrial fibrillation (≈ 5%) and torsades de pointes (in cases with markedly prolonged QTc) have also been described.
Prognosis and the ECG
Some findings are associated with higher risk:
- QTc > 500 ms: increased risk of events and sudden death
- Persistent sinus tachycardia
- Sum of ST elevation > 15 mm: higher risk of complications
Although transient, Takotsubo is not benign in every case, especially when there is hemodynamic instability.
Conclusion
Takotsubo syndrome can be a great mimic of infarction, and the ECG is a key piece of the diagnosis. Knowing its electrocardiographic patterns, especially its time course and the absence of ST elevation in V1 with ST depression in aVR, can help with the differential diagnosis and early clinical decision-making.
But be careful: when doubt persists, coronary angiography remains essential to exclude a true infarction.
References
- Scheffer MK, De Marchi MFN, de Alencar Neto JN, Felicioni SP. Eletrocardiograma de A a Z. São Paulo: Manole, 2024.
- Chhabra L, Butt N, Ahmad SA, Kayani WT, Sangong A, Patel V, et al. Electrocardiographic changes in Takotsubo cardiomyopathy. J Electrocardiol. 2021;65:28–33.
