A Second Study to Determine the Effect of GSK256073A on HVTs

Inclusion Criteria: * Healthy as determined by a responsible physician, based on a medical evaluation including history, physical examination, laboratory tests, cardiac monitoring. A subject with a clinical abnormality or laboratory parameters outside the reference range for the population being studied may be included only if the Investigator considers that the finding will not introduce additional risk factors and will not interfere with the study procedures * Healthy adult males or females between 18 and 55 years of age, inclusive. * Female subjects must be of non-childbearing potential including pre-menopausal females with documented (medical report verification) hysterectomy or double oophorectomy or postmenopausal defined as 12 months of spontaneous amenorrhea or 6 months of spontaneous amenorrhea with serum FSH levels \> 40 mIU/mL or 6 weeks postsurgical bilateral oophorectomy with or without hysterectomy, or documented hysterectomy - tubal ligation is not sufficient * Body weight \> 50 kg (110 pounds) and body mass index (BMI) between 19 and 31 where: * Subjects with QTc \< 450 msec at screening (or QTc \< 480 msec for subjects with Bundle Branch Block). * A signed and dated written informed consent prior to admission to the study * The subject is able to understand and comply with protocol requirements, instructions and protocol-stated restrictions Exclusion Criteria: * Any clinically relevant abnormality identified on the screening medical assessment, laboratory …