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Long-QT syndrome and torsades de pointes in a patient with Takotsubo cardiomyopathy: an unusual case

Saagar Mahida, Chrysoula Dalageorgou, Elijah R. Behr
DOI: http://dx.doi.org/10.1093/europace/eun336 376-378 First published online: 18 December 2008

Abstract

Takotsubo cardiomyopathy is a syndrome characterized by transient left ventricular apical ballooning associated with electrocardiogram (ECG) changes and minimal myocardial enzymatic release, mimicking acute myocardial infarction in patients without significant coronary disease at angiography. We report an unusual case of a patient who presented with Takotsubo cardiomyopathy associated with long-QT syndrome and who developed cardiac arrest secondary to torsades de pointes.The relationship between Takotsubo cardiomyopathy and abnormal repolarization has been well documented. Despite this, there have been few reports of malignant ventricular arrhythmias or sudden death. This report suggests that prolongation of QTc interval in Takotsubo cardiomyopathy may not be as benign as previously suggested but may in fact uncover an abnormality of repolarization that may be genetic in basis and carry a risk of sudden death.

Case report

A 55-year-old woman with a history of hyperlipidaemia and type 1 diabetes mellitus was admitted with a 4 h history of severe central chest pain. This had developed after witnessing a road traffic accident. Her medications included insulin, simvastatin, and aspirin, but none that prolonged the QT interval. There was no family history of note. Her initial ECG demonstrated T-wave inversion in leads aVL, V1, and V2 and a QTc interval of 510 ms (Figure 1A). Laboratory investigation revealed an elevated serum cardiac troponin T of 0.75 ng/ml and a normal serum potassium. She was treated for non-ST elevation myocardial infarction. Her pain resolved as did the T-wave inversion. The next day her ECG showed sinus bradycardia with late-coupled ventricular trigeminy and marked global T-wave inversion with severe QT prolongation (Figure 1B). The patient subsequently suffered a cardiac arrest due to torsades de pointes requiring resuscitation (Figure 1C). She had one further non-sustained episode, and was commenced on a β-blocker and remained stable.

Figure 1

(A) Admission electrocardiogram with T-wave inversion in leads aVL, V1, and V2 and QTc interval of 510 ms. (B) electrocardiogram on day 2 showing sinus bradycardia with late coupled ventricular trigeminy and marked global T-wave inversion with severe QT prolongation. (C) Telemetry revealing torsades de pointes as the cause of cardiac arrest.

The patient underwent cardiac catheterization which demonstrated only minor luminal irregularities of the coronary tree (Figure 2A). Left ventriculography demonstrated akinesis of the left ventricular apex with ballooning during systole (Figure 2B).

Figure 2

(A,B) Coronary angiogram showing only mild atheroma. (C) Left ventriculogram indicating apical ballooning during systole.

Echocardiography at 7 days showed complete resolution of regional wall motion abnormalities and complete disappearance of the left ventricular apical ballooning (Figure 3). These findings were compatible with Takotsubo cardiomyopathy. On further questioning, the patient revealed that she had suffered two syncopal episodes in her early 20s while swimming and dancing. She was offered an ICD which she declined.

Figure 3

ECHO at day 7 indicating resolution of apical ballooning: left panel diastole and right panel systole.

Two months later, the patient was seen in clinic. She was asymptomatic. Her resting ECG remained abnormal: QTc 490 ms and T-wave inversion in I and aVL (Figure 1D). The QTc interval prolonged with exercise. Given the persistence of repolarization abnormalities and a prior history of syncope, a diagnosis of underlying long-QT syndrome exacerbated by the Takotsubo cardiomyopathy was felt to be likely. Mutation analysis of KCNQ1, KCNH2, SCN5A, KCNE1, and KCNE2 failed to identify any known or likely mutations.1

Discussion

The relationship between Takotsubo cardiomyopathy and abnormal repolarization has been well documented.2 Despite this, there have been few reports of malignant ventricular arrhythmias or sudden death. Indeed the QTc interval usually only appears to be prolonged during the acute and sub-acute phases of the illness.2 We report an unusual case of a relatively young patient who presented with Takotsubo cardiomyopathy and cardiac arrest but exhibited a prior history of exertional syncope and persistent repolarization abnormality, consistent with the congenital long-QT syndrome. Unfortunately her son, the only living first-degree relative, refused evaluation. It is the only reported case where genetic testing has been attempted. Unfortunately, ∼30–40% of carriers of the congenital long-QT syndrome who undergo testing for cardiac ion channel gene mutations are genotype negative.1 Mutation analysis, therefore, does not exclude the diagnosis.

This report does suggest, however, that prolongation of the QTc interval in Takotsubo cardiomyopathy may not be as benign as previously suggested but may in fact uncover an abnormality of repolarization that may be genetic in basis, albeit genotype negative, and carry a risk of sudden death.

Conflict of interest: none declared.

References

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