Aerobic Exercise in Patients With Pulmonary Hypertension

This study will determine if a rehabilitation exercise program can help people with pulmonary hypertension (PH) increase their physical activity. Patients with PH have an increase in blood pressure in the pulmonary blood vessels (artery, vein or capillaries) that leads to shortness of breath, dizziness, fainting and other symptoms. Healthy volunteers and people with pulmonary hypertension between 21 and 75 years of age may be eligible for this study. All participants undergo the following tests and procedures: * Medical history and physical examination * 6-minute walk test: Subjects walk as fast as they can for 6 minutes on a walking track to determine their ability to participate in physical activity. * Questionnaires: Subjects complete nine questionnaires related to their fatigue, daily physical activity, mood, and so forth. * Maximum treadmill test: The exercise begins at an easy level and gradually increases until the subject says he or she can no longer continue or the investigator decides it is not safe to continue. Subjects are fitted with a mask, electrodes and light sensors to measure how well the heart is working and how well the muscles use oxygen. Patients with pulmonary hypertension undergo the following additional procedures: * Activity monitoring: Patients wear a monitor for 3 days that measures movement and heart rate. * Group assignment: Patients are randomly assigned to Group 1 (education plus aerobic exercise) or Group 2 (education followed by exercise). * Group 1 patients will attend classes three days a week at either Inova Fairfax Hospital Pulmonary Rehabilitation Center or The National Institutes of Health for 10 weeks. Two sessions a week will include a 1 hour education session as well as a 30-45 minute track or treadmill exercise session. The third session will only include exercise. During the education patients will learn about a healthy lifestyle with pulmonary hypertension. After the 10 weeks of education and exercise, subjects repe