Primary endpoints are individual time-matched changes from baseline QTcF for GSK573719/Vilanterol combination (125/25μg) and GSK573719 (500μg), 0-24 hours after dosing on Day 10. Secondary endpoints will include individual time-matched changes from baseline in QTcF for GSK573719/Vilanterol combination (500/100μg) and moxifloxacin (400mcg) 0-24 hours after dosing on Day 10. Also changes from baseline in QTci, QTcB, QT, QRS, RR, PR and ventricular rate at each time point after 10 days dosing of each GSK573719 and GSK573719/Vilanterol treatment and single dose moxifloxacin (400mg). Maximal change from baseline 0-24hours after dosing on day 10 will be derived for QTcF, QTci and QTcB for each treatment. Plasma concentrations on Day 10 (0-24 hours) and pharmacokinetic parameters of GSK573719 and Vilanterol will also be derived. Key assessments: 12- lead electrocardiogram (ECG), pharmacokinetics. Safety will be assessed by blood pressure, heart rate, clinical laboratory safety tests and collection of adverse events (AEs).