Trial Assessing the Effectiveness of Ivabradine Started at Discharge From the Observation Unit

At discharge from the observation unit, subjects will receive a pill bottle containing oral capsules containing active drug to take at home. This arm will require the subject to take the study medication BID for the duration of the study period. Neither study team nor subject will know if the pill bottle contains active drug or placebo.

At discharge from the observation unit, subjects will receive a pill bottle containing oral capsules not containing active drug to take at home. This arm will require the subject to take the study medication BID for the duration of the study period. Neither study team nor subject will know if the pill bottle contains active drug or placebo.