recruitment problem

Heart failure impairs quality of life and exercise capacity, despite an optimal medical therapy. Alternative methods, like hypoxic conditioning coupled to exercise training, must be explored and describe

All heart failure patients will have a session of 45' of bicycle exercise training (in normoxia or hypoxia) AND a one hour rest session (in normoxia or hypoxia).

Exercise training sessions will consist in a continue bicycle exercise test at 70 to 80 % of the maximal heart rate, while breathing (single blind) normoxia or hypoxia gaz.

Rest conditioning consist in a one hour of rest, while breathing (single blind) normoxia or hypoxia gaz.

For hypoxia sessions, the oxygen saturation target will be fo 85-90 % for the 4 first weeks and 80-85 % for the last 4 weeks.

Three arms :

• exercise training in NORMOXIA and rest conditioning in NORMOXIA
• exercise training in HYPOXIA and rest conditioning in NORMOXIA
• exercise training in NORMOXIA and rest conditioning in HYPOXIA

Inclusion Criteria:

• patient available for exercise training
• stable heart failure state I-II New York Heart Association (NYHA) with altered ejection fraction (EF ≤ 40 %)
• signed informed consent

Exclusion Criteria:

• unstable ischemic cardiopathy
• right ventricle dysfunction
• uncontrolled arrythmias
• rest elevated in pulmonary artery pressure (≥ 45 mmHg)
• migraine
• high altitude trip above 2500 m high during study period
• impossibility to realise a maximal bicycle exercise test

this is a single blind study patients don't know if they are breathing normal air (normoxia) or hypoxic air (hypoxia).