Exclusion criteria
| • Recent (< 6 weeks) myocardial infarction or unstable angina |
| • Supraventricular tachycardia other than atrioventricular re-entrant tachycardia |
| • Ventricular tachycardia at prestudy evaluation or at baseline electrophysiological evaluation |
| • Left ventricular ejection fraction < 20% |
| • Antiarrhythmic treatment or use of any other drugs that prolong the QTc interval taken within five half lives of start of study |
| • Amiodarone treatment taken within 4 weeks of start of the study or a serum amiodarone concentration of> 0.4 mg/l |
| • Resting QTc interval > 440 ms in a drug-free state and in the absence of pre-excitation or bundle branch block |
| • Resting supine diastolic blood pressure > 110 mm Hg |
| • Resting supine systolic blood pressure < 90 or > 200 mm Hg |