Takotsubo syndrome/QTc interval prolongation/myocardial edema/cardiac sympathetic denervation/cardiac arrhythmias: A quintet needing exploration

Cardiac arrest in takotsubo syndrome: results from the InterTAK Registry

AIMS

We aimed to evaluate the frequency, clinical features, and prognostic implications of cardiac arrest (CA) in takotsubo syndrome (TTS).

METHODS AND RESULTS

We reviewed the records of patients with CA and known heart rhythm from the International Takotsubo Registry. The main outcomes were 60-day and 5-year mortality. In addition, predictors of mortality and predictors of CA during the acute TTS phase were assessed. Of 2098 patients, 103 patients with CA and known heart rhythm during CA were included. Compared with patients without CA, CA patients were more likely to be younger, male, and have apical TTS, atrial fibrillation (AF), neurologic comorbidities, physical triggers, and longer corrected QT-interval and lower left ventricular ejection fraction on admission. In all, 57.1% of patients with CA at admission had ventricular fibrillation/tachycardia, while 73.7% of patients with CA in the acute phase had asystole/pulseless electrical activity. Patients with CA showed higher 60-day (40.3% vs. 4.0%, P < 0.001) and 5-year mortality (68.9% vs. 16.7%, P < 0.001) than patients without CA. T-wave inversion and intracranial haemorrhage were independently associated with higher 60-day mortality after CA, whereas female gender was associated with lower 60-day mortality. In the acute phase, CA occurred less frequently in females and more frequently in patients with AF, ST-segment elevation, and higher C-reactive protein on admission.

CONCLUSIONS

Cardiac arrest is relatively frequent in TTS and is associated with higher short- and long-term mortality. Clinical and electrocardiographic parameters independently predicted mortality after CA.

The natural history of takotsubo syndrome: a two-year follow-up study with myocardial sympathetic and perfusion G-SPECT imaging

PURPOSE

To investigate changes in sympathetic activity, perfusion, and left ventricular (LV) functionality in takotsubo cardiomyopathy (TTC) patients from onset (T₀) to post-onset conditions at 1 month (T₁), 1-2 years (T₂, T₃).

METHODS

Twenty-two patients (70 ± 11 years) underwent serial gated single photon emission tomography (G-SPECT) studies with ¹²³I-mIBG and ^99mTc-Sestamibi. Statistics were performed using ANOVA/Sheffé post-hoc, correlation test, and receiver operating characteristic (ROC) curve analysis (p < 0.05).

RESULTS

Patients presented at T₀ with LV ballooning and reduced early-late mIBG uptake (95%, 100%), left ventricular ejection fraction (LVEF)_G-SPECT (86%) and perfusion (77 %). Adrenergic dysfunction was greater in apex, it overlaps with contractile impairment, and both were more severe than perfusion defect. During follow-up, LVEF_G-SPECT, contractility, and perfusion were normal, while 82% and 90% of patients at T₁ and 50% at T₂ and T₃ continued to show a reduced apical early-late mIBG distribution. These patients presented at T₀-T₁ with greater impairment of adrenergic function, contractility, and perfusion. A relationship was present within innervation and both perfusion and contractile parameters at T₀ and T₁, and between the extent of adrenergic defect at T₃ and both the defect extent and age at T₀ (cut-off point 42.5%, 72 years).

CONCLUSION

Outcome for TTC is not limited to a reversible contractile and perfusion abnormalities, but it includes residual adrenergic dysfunction, depending on the level of adrenergic impairment and age of patients at onset. The number of patients, as well as degree of perfusion abnormalities were found to be higher than those previously reported possibly depending on the time-interval between hospital admission and perfusion scan.