QTc interval in takotsubo cardiomyopathy: How the activation of insular cortex interacts

Abstract

We read the interesting review article by Marafioti et al., 1 who reported on the association of prolonged QTc interval with takotsubo cardiomyopathy (Tc) in relation to right insular cortex (Ic) activity. Several points should be taken into account when interpreting the theory presented by Marafioti et al. 1 First, in a dog model, adjusted QT interval at a high parasympathetic or low sympathetic tone was significantly longer than that at the low parasympathetic or high sympathetic tone. 2 In Tc, ST-segment elevations were observed immediately after the onset. Thereafter, the T wave became progressively more negative with the QT interval prolonged. 3 Although one possible mechanism underlying Tc was increased sympathetic nervous system (SNS) activity, 4 the T-wave inversion and QT-interval prolongation were suggested to be observed in the phase of denervated SNS activity. 5 Although Marafioti et al 1 concluded that QTc prolongation in Tc was derived due to higher SNS activity, the point of time-course electrocardiography changes in relation to the autonomic nervous system was not taken into account.Second, recent studies have supported the notion that the cardiovascular system is regulated by a cortical network consisting of the Ic, anterior cingulate gyrus, and amygdala. 6 In an earlier study,