Ventricular repolarization gradients in a patient with takotsubo cardiomyopathy

Abstract

A 61-year-old woman had recurrent syncopal attacks caused by torsades de pointes associated with remarkable QT prolongation (QTc = 740 ms). Left ventriculography showed apical akinesis (ballooning) and basal hyperkinesis, but coronary angiography was normal. This was compatible with takotsubo cardiomyopathy. The wall motion of the left ventricle (LV) normalized within 2 months, and the remarkable QT prolongation and negative T-waves gradually normalized. However, polymorphic ventricular tachycardia recurred at 2.5 months after its initial onset, and we measured repolarization gradients using activation recovery intervals (ARIs) in an electrophysiological study. During atrial pacing at a cycle length of 1000 ms, the negative T-waves were observed in leads II, III, aVF, and V2-6 with QT prolongation, and the ARIs in both the epicardium and the endocardium increased from the basal site to the apical site. Moreover, the ARI tended to be longer in the epicardium than the endocardium at each level of the LV. In contrast, atrial extrastimulation changed the T-wave morphology (from negative to biphasic) in leads II, III, aVF, and V2-6 and changed the ARI gradients both from the LV basal site to the apical site and from the epicardium to the endocardium. These results suggest that the T-wave abnormalities seen in takotsubo cardiomyopathy during sinus rhythm are due to abnormal LV repolarization gradients.