J Wave and Fragmented QRS Formation During the Hyperacute Phase in Takotsubo Cardiomyopathy - Possible Markers for Severity of Myocardial Damage

Background: The J wave and fragmented QRS (fQRS) on electrocardiography are suggested to be closely related to cardiac arrhythmogenesis. Takotsubo cardiomyopathy (TIC) occasionally causes fatal cardiac conditions including life-threatening ventricular arrhythmia. There has been, however, only 1 case report describing the J wave in TTC, and fQRS has not been reported thus far in relation to clinical courses and prognosis. Methods and Results: J wave and fQRS formation were investigated in 31 consecutive patients with TIC. Nine patients (29%) had J waves and/or fQRS (group A), whereas the remaining 22 did not (group B). The J wave (4 patients), fQRS (4 patients), or both (1 patient) appeared transiently during the hyperacute phase. Left ventricular ejection fraction was significantly lower in group A. Summed defect score of single-photon emission computed tomography using iodine 123 beta-methyl-p-iodophenyl-pentadecanoic acid, and creatine kinase MB isozyme (CKMB) were significantly higher in group A. On multivariate analysis CKMB was a significant indicator of J wave or fQRS. Moreover, the J wave was a significant indicator for cardiac death and/or ventricular tachyarrhythmia (odds ratio, 11.5; P=0.026). Conclusions: Patients with TTC frequently had J waves and/or fQRS during the hyperacute phase, and which were associated with myocardial damage. J wave was also an indicator for cardiac death and/or ventricular tachyarrhythmia. J waves and fQRS may be useful markers for myocardial damage.