Interatrial block and takotsubo syndrome

We read with interest the ‘images electrophysiology’ manuscript published by Miyahara et al.1 in the Journal. The authors show an interesting electrocardiogram (ECG) from an 86-year-old woman who presented with takotsubo cardiomyopathy after a successful cryoballoon pulmonary vein isolation and cavotricuspid isthmus ablation. We would like to comment on some other relevant ECG aspects of this interesting case. The follow-up ECGs show advanced interatrial block (IAB) manifested as a P-wave duration ≥120 ms with a biphasic morphology in the inferior leads. Interatrial block represents a conduction delay between the right and left atria that is associated to an increased risk of developing atrial fibrillation (AF) and stroke. We have recently studied the presence of IAB in patients with takotsubo cardiomyopathy.2 Advanced IAB was associated with the composite endpoint of 12-month all-cause death/hospital readmission. On the other hand, AF recurrences after pulmonary vein ablation are common. Advanced IAB has been associated with AF recurrences post pharmacological cardioversion3 and after successful pulmonary vein isolation.4 Also, advanced IAB has been associated with new-onset AF after cavotricuspid isthmus ablation.5 To summarize our ECG analysis, the development of advanced IAB in this specific patient with new diagnosis of takotsubo is clinically relevant and should be highlighted to properly design strategies for AF monitoring in the future. Conflict of interest: none declared.