The report by Singh et al, published online ahead of print on February 18, 2015, in The American Journal of Cardiology , about cardiac arrest (CA) and takotsubo syndrome (TTS), provides a lot of food for thought! The key point is whether TTS was the precipitant or the consequence of CA, in the 77 patients whom the investigators reported. The 17 patients (primary TTS) who had CA after the diagnosis of TTS were older by a mean of 15 years than subgroup B, and who subsequently developed longer corrected QT interval, and TTS-induced polymorphic ventricular tachycardia, represent the “classic” TTS subgroup, who had CA in the subacute phase of the illness. The 60 patients (secondary TTS), who were diagnosed with takotsubo cardiomyopathy (TTC) after CA, were younger, had shorter corrected QT interval, and were hypotensive after resuscitation. This subgroup of patients appears to comprise subjects who either had TTS and experienced a CA in the hyperacute phase of their illness or had a CA with a morbid substrate other than TTS, and after resuscitation they developed TTS (Figure 2 of the report). The investigators remark that the “TTC-related hypotension was the major cause of CA in the acute phase” (e.g., patients during anesthesia), but one could also see the hypotension as an accompanied feature of patients who had just been resuscitated from unrelated-to-TTS CA or as a characteristic accompaniment of some of the patients with TTS who present with hypotension (with or without bradycardia), attributed to influences of a hyperactive parasympathetic autonomic nervous system, as a cause of TTS. The investigators could aid in partially clearing the “murky waters” of this complex issue, by trying to provide data (if available) on the following: (1) How many patients in the secondary TTS subgroup were bradycardic, hypotensive, or hypotensive/bradycardic at the post-CA time point? (2) Was there evidence of prolonged resuscitation and/or excessive use of adrenaline, in the patients with “secondary TTC”? The investigators wisely recommend that patients with “secondary TTC” should be evaluated for “identifiable inheritable arrhythmias or structural heart disease.” My conceptualization of TTS and CA is less “murky,” after reading the investigators’ report.