High-Sensitivity Cardiac Troponin Levels in Supraventricular Tachyarrhythmias.

BACKGROUND: High-sensitivity cardiac troponin assays have provided a significant contribution for the early diagnosis of cardiovascular events. However, elevated cardiac troponin levels may occur in other clinical situations as supraventricular tachyarrhythmias with concerns about the mechanism of this elevation. OBJECTIVES AND METHODS: The goal of this study was to describe the performance of high-sensitivity cardiac troponin T (hs-cTnT) assay in patients presenting to the emergency department with a primary diagnosis of supraventricular tachyarrhythmia and to evaluate its relation with cardiovascular events during follow-up. RESULTS: One hundred patients were included; mean age was 64 ± 12 years and 59.8% were men. The most common arrhythmia at admission was atrial fibrillation (68%), followed by atrial flutter (16%) and reentrant tachycardia (16%). The results of the first determination of hs-cTnT were positive (>14 ng/L) in 44.2% of the patients and the second determination was positive in 50.7% of the cases. The variation between the first and the second troponin levels was 1 (0-5) ng/L, and was >7 ng/L in 24.6% of the cases, with a clear trend toward higher troponin values in reentrant tachycardias. Four events were reported at 30 days; in all the cases the patients had presented atrial fibrillation and there were no significant differences in hs-cTnT values. CONCLUSIONS: There are a significant number of patients with supraventricular tachyarrhythmias who present elevated hs-cTnT levels. The association of this elevation with cardiovascular events seems to be very low.

Predictors of conversion of recent-onset atrial fibrillation treated with vernakalant.

BACKGROUND: Vernakalant is an available drug for the treatment of recent-onset atrial fibrillation, producing conversion between 55% and 87% of the patients treated. In this sense, little is known about the predictors of conversion with this agent. The aim of our study was to analyze the predictors of conversion in our 2-year experience using vernakalant for the treatment of recent-onset atrial fibrillation. METHODS: One hundred twenty-one patients with recent-onset atrial fibrillation without hemodynamic impairment received pharmacological treatment with vernakalant. Clinical variables, history of cardiovascular diseases, and echocardiographic data were recorded. RESULTS: Mean age was 58.1 ± 13.9 years and 13.4% of patients had structural heart disease. Conversion to sinus rhythm was achieved in 84.5% of patients, and 46% required the second dose of vernakalant. After analyzing the predictors of conversion, the presence of structural heart disease was significantly larger in the group without conversion (35.3 vs 9.7%; P = 0.02). The mean ejection fraction in the group with conversion was 61.05 ± 5.7% versus 54.9 ± 8.4% in the group without conversion (P = 0.016). After dichotomizing the variable ejection fraction, patients with ejection fraction <55% had a lower conversion rate (P = 0.001). CONCLUSION: In our study, the absence of any kind of structural heart disease and preserved systolic function were associated with greater conversion rate with vernakalant.