title: Clinical significance of changes in the corrected QT interval in stress-induced cardiomyopathy.
abstract: OBJECTIVE
  Although transient changes in the electrocardiogram (ECG) of patients with stress-induced cardiomyopathy (SCMP) are common, there are little data about ECG changes in patients with SCMP and the clinical implications of these variations.
  
  
  METHODS
  We investigated a total of 128 patients (age, 63.2 ± 15.4 years; female, 60.9%) diagnosed with SCMP. We compared the ECGs taken after SCMP diagnosis and during the recovery phase to those taken before SCMP diagnosis under baseline conditions. All patients were divided into two groups according to corrected QT (QTc) interval changes: recovered QTc group (QTc in SCMP > QTc in recovery phase, n = 77) and nonrecovered QTc group (QTc in SCMP ≤ QTc in recovery phase, n = 51).
  
  
  RESULTS
  In comparison of baseline, SCMP, and recovery phase, we found the mean heart rate (81.5 ± 18.7, 96.8 ± 25.3, and 83.0 ± 19.4/min, respectively; p < 0.001), frequencies of ST segment elevation (0.0%, 8.6%, and 1.6%, p = 0.004), ST segment depression (0.0%, 6.3%, and 1.6%, p = 0.007), T wave inversion (4.4 %, 43.8%, and 61.7%, p < 0.001), and QTc (447.4 ± 35.3, 488.9 ± 67.1, and 468.0 ± 49.5, p < 0.001) showed significant changes. In-hospital mortality (9.1% vs. 25.5%, p = 0.012) and critical care (54.5% vs. 72.5%, p = 0.040) occurred more frequently in the nonrecovered QTc group than in recovered QTc group.
  
  
  CONCLUSIONS
  The QTc can be prolonged in patients with SCMP. Short-term mortality was increased in patients where the QTc did not recover.
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Severance Cardiovascular Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Jung-Hee
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Severance Cardiovascular Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Jae-Sun
authors.initials: JS
authors.lastname: Uhm
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Severance Cardiovascular Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Dong Geum
authors.initials: DG
authors.lastname: Shin
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Severance Cardiovascular Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Boyoung
authors.initials: B
authors.lastname: Joung
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Severance Cardiovascular Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Hui-Nam
authors.initials: HN
authors.lastname: Pak
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Severance Cardiovascular Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Young-Guk
authors.initials: YG
authors.lastname: Ko
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Severance Cardiovascular Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Geu-Ru
authors.initials: GR
authors.lastname: Hong
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Severance Cardiovascular Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Moon-Hyoung
authors.initials: MH
authors.lastname: Lee
mesh_terms: D000200:Action Potentials; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001145:Arrhythmias, Cardiac / Q000175:diagnosis / Q000209:etiology* / Q000401:mortality / Q000503:physiopathology; D004452:Echocardiography; D004562:Electrocardiography; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology*; D006339:Heart Rate; D017052:Hospital Mortality; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D020127:Recovery of Function; D012189:Retrospective Studies; D012307:Risk Factors; D054549:Takotsubo Cardiomyopathy / Q000150:complications* / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology; D013997:Time Factors; D055815:Young Adult
keywords: Electrocardiography; Mortality; QTc interval; Takotsubo cardiomyopathy