Comparison of electrocardiographic findings between the midventricular ballooning form and apical ballooning form of takotsubo cardiomyopathy.

BACKGROUND: Several reports have recently described the variant form of takotsubo cardiomyopathy exhibiting midventricular ballooning. The purpose of this study was to assess electrocardiographic (ECG) findings on admission in patients with midventricular ballooning.

HYPOTHESIS: ECG findings are different between the midventricular ballooning form and apical ballooning form of takotsubo cardiomyopathy.

METHODS: We reviewed ECGs on admission in 6 patients with midventricular ballooning and 20 patients with apical ballooning. The sum of ST segment elevation in leads V1 to V3 or in leads V4 to V6 was obtained. The number of leads showing ST segment elevation and/or T wave inversion was also obtained. These ECG findings were compared between the 2 groups.

RESULTS: In midventricular ballooning, ECG changes including ST segment elevation and/or T wave inversion were observed frequently in leads V2 and V3, and were not observed in leads II, III, -aVR, aVF, V5, and V6. On the other hand, in apical ballooning, they were found in all leads. They were most common in leads V4 and V5. The sum of ST segment elevation in leads V1 to V3 was similar (2.6 ± 2.0 mm vs 2.7 ± 2.0 mm, P = not significant), and the sum of ST segment elevation in leads V4 to V6 was significantly lower in midventricular ballooning than apical ballooning (0.4 ± 0.8 mm vs 3.5 ± 3.0 mm, P<0.05). The number of leads showing ST segment elevation and/or T wave inversion was significantly lower in midventricular ballooning than apical ballooning (3.2 ± 1.0 leads vs 6.3 ± 2.2 leads, P<0.01).

CONCLUSIONS: Our data suggested that midventricular ballooning may show limited ECG changes despite broad wall motion abnormality.