Sedation With Dexmedetomidine During Cardiac Catheterization

Inclusion Criteria: 1. Subjects with a diagnosis of pulmonary hypertension 2. Procedure - Planned cardiac catheterization procedure with spontaneous ventilation and natural airway 3. Patients who want sedation or general anesthetic for the procedure. 4. Age: Subjects ≥8 years and \< 21 years 5. Adequate Renal Function defined As:Serum creatinine ≤ 1 mg/dL 6. Adequate Liver Function defined As:Total bilirubin ≤ 1.5 mg/dL alanine aminotransferase (ALT) ≤ 2 times the upper limit of normal 7. Informed Consent: All parents or legal guardians must sign a written informed consent. 8. Signed assent when developmentally appropriate 9. Negative pregnancy test in menstruating females and all females ≥ 12 yr Exclusion Criteria: 1. Refusal of Informed Consent/Assent 2. Subjects with single ventricle physiology 3. Pregnant or lactating females 4. Subjects with syndromes e.g. Trisomy 21 will be excluded due to variability in pharmacodynamic responses and airway instability during sedation 5. Inappropriate clinical or developmental status to undergo cardiac catheterization under conditions of spontaneous ventilation with a natural airway 6. Second or third degree heart block 7. Moderate - severe right ventricular dysfunction/failure 8. Subjects who, in the opinion of the investigator, are not appropriate candidates for an investigational drug study e.g. behavioral or anxiety disorders, inability to lie supine 9. Concomitant Medications - Investigational Drugs: Subjects who have received another investigational drug protocol 30 days prior to enrollment in this study 10. Subjects who in the opinion of the investigator may be non compliant with study schedules or procedures. 11. Non-English speaking subjects will be excluded due to need for direct communication from clinical and study staff during study procedures and the ability to complete study tools.