The purpose of this study is to evaluate the effects of airway bilevel positive pressure on the improvement of exercise tolerance in patients with decompensated heart failure.

Heart failure causes limitation of functional capacity and worsening of exercise tolerance. The airway pressure as adjuvant of cardiac rehabilitation has demonstrated improvement of functional capacity, decrease of respiratory work, increase of oxygenation and pulmonary compliance. Objective: to evaluate the effectiveness of the bilevel positive airway pressure (BILEVEL) in the increase of exercise tolerance in patients with decompensated heart failure. Method: this is a cross-over randomized clinical trial, with individuals who will undergo a submaximal progressive exercise test of the lower limbs with a cycle-ergometer using continuous positive airway pressure (CPAP) and BILEVEL in a random order. Patients will also be evaluated using a health related quality of life questionnaire, pulmonary function test, inspiratory muscle and peripheral muscle strength tests. Hypothesis: The increase in exercise tolerance might be greater during the use of BILEVEL.

Inclusion Criteria:

• subjects who has heart failure functional class II or III of New York heart association
• over 18 years
• non-smokers
• without cognitive or motor deficit
• without vasoactive drugs or low doses
• without recent acute myocardial myocardium (<1 year)
• without recent cardiac surgery (<1 year)
• without pulmonary disease
• without bronchodilators

Exclusion Criteria:

• unstable angina
• atrial fibrillation and atrioventricular block third degree
• frequent vomiting
• respiratory instability while collecting data