Takotsubo cardiomyopathy and the long-QT syndrome: an insult to repolarization reserve

Abstract

Takotsubo cardiomyopathy (TCM) is a transient syndrome with acute, subacute, and chronic phases, and is commonly induced by emotional or physical stress. It is characterized by chest pain, electrocardiogram (ECG) changes, and minimal myocardial enzymatic release mimicking acute myocardial infarction in patients with unobstructed coronary arteries on angiography. Assessment of left ventricular function in patients with TCM reveals apical ballooning and hypokinesia with the preservation of basal contraction. Electrocardiogram changes include ST-segment elevation, the evolution of marked anterior T-wave inversion, and prolongation of the QT interval. These features all appear to resolve with time.1 Wedekind et al. 2 report a case of clinically silent pre-existing long-QT syndrome (LQTS) exacerbated by TCM and resulting in life-threatening arrhythmias. This mirrors our own description last year of a similar case3 and prompts an evaluation of the true significance of QT prolongation in this context. The association between TCM and QT prolongation has been well documented ( Table 2 ). Seth et al. 4 reported 12 cases of TCM with an average QTc interval of 478ms. Similarly, Abe et al. 5 described 17 patients, most of whom had a prolonged QTc interval in the acute and subacute phases of the condition. The QT interval normalized in all cases between 97 and 191 days from the onset of symptoms. As part of a report on 13 patients by Desmet et al. ,6 each patient's ECG during the acute phase was described with QTc intervals ranging from 310 to … *Corresponding author. Tel: +44 2087255939, Fax: +44 2087253328, Email: ebehr{at}sgul.ac.uk