Autonomic function in Takotsubo syndrome long after the acute phase

Area of Science:

• Cardiology
• Autonomic Nervous System Research
• Exercise Physiology

Background:

• Takotsubo Syndrome (TS), or stress-induced cardiomyopathy, is characterized by acute sympathetic overactivity.
• Autonomic nervous system adaptations long after the acute phase of TS remain understudied.
• Investigating persistent autonomic dysfunction is crucial for understanding long-term TS outcomes.

Purpose of the Study:

• To determine if autonomic function remains impaired in Takotsubo Syndrome patients more than one year after the acute event.
• To compare the autonomic responses to maximal exercise in recovered TS patients, healthy individuals, and post-myocardial infarction (post-MI) patients.

Main Methods:

• Maximal exercise testing was performed in 24 TS patients, 25 healthy subjects, and 22 post-MI patients.
• Participants underwent a minimum 3-day washout period from beta-blocker medication prior to testing.
• Heart rate recovery (HRR) and chronotropic response (CR) were assessed to evaluate autonomic function.

Main Results:

• TS patients demonstrated significantly lower heart rate recovery (HRR) compared to healthy subjects (19.2±9.7 bpm vs. 27.7±8.3 bpm, p=0.003).
• HRR in TS patients was comparable to that of post-MI patients (19.3±8.4 bpm, p=0.99).
• A trend towards decreased chronotropic response (CR) was observed in TS and post-MI patients compared to healthy subjects (p=0.06).

Conclusions:

• Takotsubo Syndrome patients exhibit blunted parasympathetic reactivation after exercise, persisting long after the acute phase.
• This impaired vagal control of heart rate post-exercise in TS patients is similar to that seen in post-MI patients.
• The findings suggest persistent abnormalities in autonomic cardiovascular regulation following Takotsubo Syndrome.