<qa>  What is the risk of a patient being able to do?The valve disorders are a special group of heart diseases with long period without clinical manifestations, when there is the appearance of symptoms, the patient is a likely candidate for surgery. In many surgical complications can occur, including the respiratory cause and immobility in bed culminating in the need for intensive care. Early mobilization exercises conducted by physical therapy in critically ill patients is to minimize complications related to immobility in bed from surgery that is performed in exchanges of heart valves. To investigate the influence of a cardiac rehabilitation program on cardiac function Heart Rate Varibility and free radicals oxidative stress in patients undergoing surgical heart valve replacement. The study is being conducted at the Clinical Hospital Gaspar Viana of Belém, in March 2014 period to March 2016, with the proposing institution the Methodist University of Piracicaba. The study included 60 volunteers aged 18 to 60 year old male with surgery scheduling of heart valve replacement. The volunteers were divided into 2 groups the control group who underwent rehabilitation proposed by the hospital with simple exercises like deep breathing exercises to improve cough, move your arms and rhythmically legs to maintain joint mobility, the second group It was called Early Mobilization Group, where volunteers beyond rehabilitation protocol proposed by the hospital, held exercises in a cycle ergometer, The volunteers were instructed to pedal lying comfortably with moderate intensity for 30 minutes. All groups performed this protocol lasting 4 days. Oxidative stress was analyzed and cardiac function before surgery, after surgery in the first and fifth postoperative. The Oxidative Stress is analyzed by puncturing a drop of blood and to analyze the photographed area coagulum formed. Cardiac function Heart Rate Variability will be analyzed using a heart rate monitor brand Polar RS800CX model being evaluated lying down, then the data is transferred to the computer and analyzed in a program called Kubios HRV. After collecting the data will be analyzed in Biostat 5.2 program. The possible risks to the research subject is the inconvenience of collecting the blood sample, the onset of pain resulting from the mobilization of the rehabilitation protocol. However, the emergence of at least one of the risks mentioned above, the procedure and or service must be stopped and perform passive stretching or temporary home until everything returns to normal. In addition, there may be a risk of contamination to volunteer for collecting blood, however this risk is minimized when using materials such as sterile needles and blades. The research brings benefit as increased range of motion and muscle strength, decreased pain, functional improvement, providing improvement in quality of life and functional independence and reduced hospital stay. 