From the Guidelines
Takotsubo cardiomyopathy is characterized by ECG changes that mimic acute myocardial infarction, including ST-segment elevation, T-wave inversions, and QT interval prolongation, which typically normalize as the condition resolves. These ECG abnormalities are not specific to the condition and can be seen in other cardiac syndromes. Common ECG findings in Takotsubo cardiomyopathy include:
- ST-segment elevation, most often in the precordial leads, which tends to resolve quickly, often within 24-48 hours 1
- T-wave inversions, which can be deep and widespread, and may persist for weeks to months 1
- QT interval prolongation, which can be significant and increase the risk of ventricular arrhythmias 1 The ECG changes in Takotsubo cardiomyopathy reflect the myocardial stunning and electrical disturbances caused by the catecholamine surge that triggers the syndrome, affecting primarily the apical segments of the left ventricle. It is essential to note that these changes do not correspond to a single coronary artery distribution, unlike in myocardial infarction. The most recent and highest quality study on this topic is the 2018 international expert consensus document on Takotsubo syndrome, which provides guidance on the diagnostic workup, outcome, and management of the condition 1.
In terms of management, the use of QT-interval prolonging drugs should be cautious in the acute phase due to the risk of inducing torsades de pointes or ventricular tachycardia and fibrillation 1. Additionally, anticoagulation with intravenous/subcutaneous heparin may be considered in patients with severe LV dysfunction and extended apical ballooning to prevent LV thrombus and subsequent systemic embolism 1. The 2018 expert consensus document also recommends avoiding the administration of nitroglycerin in the presence of LV outflow tract obstruction, as it can worsen the pressure gradient 1.
Overall, the ECG changes in Takotsubo cardiomyopathy are a crucial aspect of the condition's diagnosis and management, and clinicians should be aware of the typical patterns and potential complications associated with these changes. The 2018 international expert consensus document provides the most up-to-date guidance on the management of Takotsubo cardiomyopathy, and its recommendations should be followed in clinical practice 1.
From the Research
ECG Changes in Takotsubo Syndrome
- Negative T waves and QTc prolongation are common ECG findings in patients with Takotsubo syndrome 2
- The mean number of leads with negative T waves, the highest value of negative T wave deflection, and the sum of all negative T waves are significantly higher in patients with Takotsubo syndrome compared to reference ECGs 2
- QTc max and QTc mean prolongation are also observed in patients with Takotsubo syndrome 2
- T waves are significantly more positive in pathological ECGs in leads aVR and V1 compared to reference ECGs 2
Comparison with ST-Elevation Myocardial Infarction
- The presenting ECG in Takotsubo syndrome shows significantly fewer total abnormal leads, comparable number of ST-elevation leads, but lesser total magnitude of ST-elevation compared to ST-elevation myocardial infarction 3
- Takotsubo patients develop more widespread T wave inversion and/or deeper T waves compared to myocardial infarction patients after day 0 3
- There is a progressive increase in QTc in Takotsubo patients vs a decrease in myocardial infarction patients between days 0-3 3
Diagnostic Implications
- The differences in presenting ECG between Takotsubo syndrome and myocardial infarction are significant but subtle, reinforcing the importance of acute cardiac catheterisation for accurate diagnosis 3
- The progressive increase in the depth and spread of T-waves and QTc duration in Takotsubo syndrome vs myocardial infarction may aid in diagnostic confidence in patients with bystander non-obstructive coronary disease 3