Abstract 13021: Double-Peaked Trajectory of the Corrected QT Interval and Its Sex Differences During the Clinical Course of Takotsubo Syndrome

Abstract

Background: In the general population, the normal value of the corrected QT (QTc) interval for women is under 450 ms, which is longer than that of men (under 430 ms). There have been reported several sex differences in characteristics of takotsubo syndrome (TTS). Prolonged QTc interval is a relatively common electrocardiographic finding in TTS. Research Question: Little is known about the sex differences in the trajectory of QTc interval during the clinical course of TTS. Aim: The aim of this study was to determine the change in the QTc interval from the acute onset to one year later by sex. Methods: This study retrospectively included 85 consecutive patients with TTS admitted to our hospital from 2015 to 2023. A total of 848 twelve-lead electrocardiograms (ECG) performed from the date of diagnosis (day 0) within one year were analyzed. Mean QTc intervals were calculated by the day from day 0 to day 16, and after day 17, by defined periods (day 17-30, 31-60, 61-90, 91-180, 181-360). Results: Fifty-eight (68%) patients were women. There were no significant differences between women and men in age (71 ± 13 years vs. 67 ± 10 years, P =0.13), preceding physical trigger (55% vs. 70%, P =0.24), and all-cause mortality within one year (17% vs. 19%, P >0.99). On day 0, the QTc intervals within the normal range were observed both in women and men. The first peak of the QTc interval was observed on day 2 with the mean QTc interval of 475 ± 70 ms in women, and 474 ± 60 ms in men. Once the QTc interval shortened after the first peak, it prolonged again and the second peak was observed around the second week from the onset. In the second peak, the QTc interval was found to be longer in men (503 ± 32 ms) compared to women (471 ± 56 ms). After the second peak, the QTc interval gradually normalized, and never prolonged again until one year. Conclusions: The double-peaked trajectory of the QTc interval was clearly observed during the clinical course of TTS. The variability of the QTc interval was greater in men than in women.