RESULTS: Eight patients were recruited, including three patients with tracheal stenosis, two patients with tracheal and unilateral stenosis, and three patients with left or right main bronchial with right intermedius stenosis. Their median age was 37.5 (25-52), male to female ratio being 3:5. Mean VO2peak was 75 ml/min.(39-97%pred), with four patients’ VO2peak exceeding 84% predicted. Patients could be limited by ventilation (1/8), and flow limitation was observed in only three patients. However, seven out of eight patients had steeper HR-VO2 relationships, in which cardiac limitation was manifested by lowered oxygen pulse in three patients (one of who accompanied with flatterned VO2/WR), by much lower heart rate reserve in two. One of the patients was retested two years after repeated interventions. Although he was still limited by flow and flow-volume curve was typical of fix upper airway obstruction, his VO2peak improved from 60 to 86 ml/min. His oxygen pulse at peak exercise rose from 65bpm to 94bpm.The slope of HR verses VO2 was decreased.