Baseline NT-ProBNP level predicts success of cardioversion of atrial fibrillation with flecainide.

BACKGROUND: Patients with acute-onset symptomatic atrial fibrillation (AF) can be treated with flecainide. However, flecainide may induce arrhythmias and/or exaggerate heart failure. Therefore, validated markers to predict the efficacy of flecainide and prevent adverse effects are required. We hypothesised that lower NT-proBNP plasma levels correlate with higher success rates of cardioversion with flecainide in patients with AF. METHODS: In this prospective single-centre study, we included 112 subsequent patients with acute-onset (< 24 h) symptomatic AF. Patients with symptoms of heart failure and ECG signs of ischaemia were excluded. Baseline laboratory measurements, including NT-proBNP, were done. Echocardiograms were performed ~ 2 weeks after restoration of SR. RESULTS: Cardioversion with flecainide was successful in 91 patients (87 %). NT-proBNP was lower in patients with successful cardioversion (P < 0.001). Logistic regression indicated NT-proBNP as an independent predictor of successful cardioversion. A cut-off NT-proBNP value of 1550 pg/ml provided optimal test accuracy to predict successful cardioversion. CONCLUSION: In patients with < 24 h of symptomatic AF, NT-proBNP levels up to 1550 pg/ml correlate with high success rates (94 %) of cardioversion with flecainide. Conversely, NT-proBNP higher than 1550 pg/ml correlates with poor success rates (36 %). Further research is needed to validate the predictive value of NT-proBNP for successful cardioversion with flecainide.

Low dose oral haloperidol does not prolong QTc interval in older acutely hospitalised adults: a subanalysis of a randomised double-blind placebo-controlled study.

BACKGROUND: Haloperidol is the most frequently prescribed antipsychotic for delirium symptoms. The risk of QTc prolongation often raises concerns, although the effect of haloperidol on QTc interval has not yet been investigated in a randomised placebo-controlled fixed-dose study. METHODS: A subanalysis of a randomised double-blind placebo-controlled study was conducted to evaluate the effect of prophylactic haloperidol 1 mg or placebo 1 mg orally twice-daily (maximum of 14 doses) on QTc interval in patients aged 70 years and over. Bedside, 12-lead ECGs were recorded before, during and after the one-week intervention period. Automatic QTc measurements were obtained in addition to manual measurements of QT and RR intervals, blinded for treatment status. Manual measurements were corrected (QTc) using Bazett (QTc-B), Framingham (QTc-Fa), Fridericia (QTc-Fi) and Hodges (QTc-H) methods. Mixed model analyses were used to test for differences in longitudinal course of QTc between patients receiving haloperidol and placebo. RESULTS: ECG recordings of 72 patients (haloperidol n = 38) were analysed, 45.8% male. Median (range) haloperidol serum concentration on day 4 was 0.71 (0.32-1.82) µg/L (n = 23). Longitudinal course of mean QTc did not significantly differ between treatment arms for any of the automatic or manually derived QTc values. CONCLUSIONS: Low dose oral haloperidol did not result in QTc prolongation in older acutely hospitalised patients. Results may not be generalizable to patients with existing ECG abnormalities such as atrial fibrillation.