Ventricular repolarization gradient and electrocardiogram characteristics of Tako-Tsubo cardiomyopathy

The prognostic value of dispersion of repolarization in stress cardiomyopathy

INTRODUCTION

Although abnormalities of ventricular repolarization are a hallmark of SC, their clinical impact on management remains to be determined. This study sought to evaluate the prognostic value of dispersion of repolarization in stress cardiomyopathy (SC) with regards to major cardiac events (MCE), recovery time, and recurrence.

METHODS

This study analyzed data from258 patients with SC, from January 2009 to January 2018. Standard 12 lead ECG recordings during the acute, subacute, and recovery phases were collected for each eligible patient. Logistic regression was used to identify independent predictors of MCE, a composite of 30 day all-cause mortality, cardiogenic shock, life-threatening ventricular arrhythmias, and stroke.

RESULTS

Among the 101 eligible patients (80.2% females, mean age 45.8 ± 11.5 years) in the study cohort, MCE occurred in 16 patients (15.8%). Cox regression analysis identified two independent predictors of MCE: increased ΔQT dispersion ≥ 40 ms (HR 1.31, 95% CI 1.05-9.77, p = 0.029) and increased Δnegative T wave amplitude dispersion ≤ -2.0 mV (HR 1.25, 95% CI 1.11-11.93, p = 0.018) during the subacute phase. The final regression model had good accuracy (sensitivity 81.3%, specificity 96.5%) and discriminative power (AUC 0.89, 95% CI 0.83-0.95). Kaplan-Meier analysis revealed that there was increasing MCE in patients with zero, one, or two predictors (log rank p < 0.001). In addition, patients with increased dispersion also had a significantly longer time to achieve complete recovery (21.4 ± 6.8 vs. 8.5 ± 4.3 days, p = 0.012) and a higher incidence of recurrence (31.3% vs. 2.4%, p = 0.011) of SC.

CONCLUSION

Evaluation of dynamic changes of dispersion of repolarization is a simple bed-side tool with high predictive accuracy for prognostication of short term adverse outcomes, delayed recovery, and recurrence in patients with SC.

Diagnosis of Takotsubo cardiomyopathy

Takotsubo cardiomyopathy, also known as left ventricular apical ballooning syndrome and stress-induced cardiomyopathy, is typically characterized by transient systolic dysfunction of the apical and mid-segments of the left ventricle, in the absence of obstructive coronary artery lesions. Patients may present with symptoms and signs of acute coronary syndrome, and the provider is challenged to differentiate between these conditions. In this review, we guide the reader through the diagnostic pathway, focusing on differential diagnoses and diagnostic criteria for takotsubo cardiomyopathy.