Inclusion Criteria:

• Confirmed diagnosis of Friedreich's Ataxia (FA) by Frataxin genetic testing and/or Frataxin enzyme analysis.
• Between age 10 and 50 years of age, inclusive.
• Body weight of 25 kilograms or higher.
• Minimum of one affected organ (cardiac or neurological) system, as evidenced by clinical signs/symptoms.
• Disease duration ≤7 years, based on onset date of FA symptoms.
• Has no known contraindication to gadolinium contrast such as severe allergy or Glomerular Filtration Rate <30 ml/min/m^2.
• Has no known contraindication to non-contrast Magnetic Resonance Imaging (MRI) evaluation such as pacemaker or magnetically active metal fragments.
• Women of childbearing age must:
  • Have a negative pregnancy human chorionic gonadotropin test prior to receiving study drug;
  • Agree to use contraception for the duration of the study drug dosing, plus 1 month after completion of the study.

Exclusion Criteria:

• Advanced cardiac failure, New York Heart Association (NYHA) Classification Scale-Class IV (advanced stage heart failure).
• Clinically significant comorbidities that may also lead to cardiomyopathy, for example long standing hypertension, familial cardiomyopathy.
• Clinically significant comorbidities that would, in the opinion of the investigators, compromise the interpretation of test results.
• Pregnant, breast-feeding or planning to become pregnant during study timeframe.
• Contraindications to regadenoson; i. e., second- or third-degree atrioventricular (AV) block or sinus node dysfunction.
• Has received an investigational drug within 30 days of baseline visit.
• Thrombocytopenia (< 125 x 10^9/Liter) or prolonged Prothrombin Time/Partial Thromboplastin Time (PT/PTT) at baseline.
• Clinically significant hypotension (systolic blood pressure < 90) due to heart failure or other conditions.