1. During the first 2-week period: Subjects will be randomized to first receive either the ranolazine or a placebo pill (sugar pill with no active medicine). Subjects will take the extended-release ranolazine or a placebo pill for a total of 2 weeks. Subjects will take 500 mg twice daily for the first 1 week and then 1000 mg twice daily for an additional 1 week. Subjects who are unable to take the higher dose due to side effects will remain on 500 mg twice daily for the entire study period. After the 2 weeks, the participant will have a Cardiac MRI and complete study questionnaires. These tools will allow us to evaluate if the participant is doing better on the medication.