Clinical correlates and prognostic significance of electrocardiographic abnormalities in apical ballooning syndrome (Takotsubo/stress-induced cardiomyopathy)

Background

Apical ballooning syndrome (ABS) is a unique transient cardiomyopathy that mimics an acute myocardial infarction. The relative frequency of ST-segment elevation on the 12-lead electrocardiogram (ECG) and its prognostic significance is unknown. The aims of this study were to evaluate the frequency and the clinical correlates of ST- and T-wave abnormalities on the admission ECG in patients with ABS.

Methods

Patients were retrospectively identified from the cardiac catheterization database—those who underwent coronary and left ventricular angiography and fulfilled the Mayo criteria for ABS during the period January 1988 to November 2006. They were divided into 3 groups according to the presence of (1) ST-segment elevation (>1 mm in 2 contiguous lead) or new left bundle branch block, (2) T-wave inversion (>3 mm in 3 contiguous leads) but no ST shift, and (3) nonspecific ST-T abnormalities or normal ECG at the time of admission. Clinical and echocardiographic findings were compared between groups.

Results

Among the 105 patients, 36 (34.2%), 32 (30.4%), and 37 (35.2%) patients were in the three respective groups. There were no differences in the clinical characteristics, ejection fraction, and outcomes between the 3 groups. Over a median follow-up of 2.5 years, there was no difference in the 5-year recurrence rate of ABS between the 3 groups (13%, 5%, 17% patients, respectively, P = .25). The 5-year mortality was similar in the 3 groups (24%, 7.3%, 10.8%, P = .58).

Conclusions

ST-segment elevation is absent in two thirds of patients with ABS. Thus, the cardiomyopathy may mimic either ST-elevation or non–ST-elevation myocardial infarction. The ECG abnormalities at presentation do not correlate with the magnitude of ventricular dysfunction or outcomes.