Effects of acute oxygen supplementation on functional capacity and heart rate recovery in Eisenmenger syndrome

Abstract Background Eisenmenger syndrome (ES) precipitates the extreme manifestation of pulmonary hypertension, which leads to severe functional limitation and poor quality of life. The propose of the current study was: 1) examined the acute effects of 40% oxygen supplementation during the 6-minute walk test (6MWT); and 2) evaluate the relation between exercise capacity and clinical cardiac parameters in patients with ES. Methods Thirty subjects were prospectively included; all were submitted to a 6MWT with compressed air and with 40% of oxygen. Heart rate recovery at the first minute (HRR 1 ) and perceived effort Borg scale for dyspnea and lower limb fatigue were recorded in both tests scenarios. Results The 6MWT distance was modestly, negatively associated with pulmonary vascular resistance (PVR) [r=0.46, p=0.02]. Patients improved 6MWT distance (p 1 (p FAC ) [r=0.50, p=0.03; r=0.64, p Conclusion Acute 40% oxygen supplementation in patients with Eisenmenger syndrome led to an improvement in 6MWT distance, faster HRR 1 and lower dyspnea and lower limb fatigue perception. Moreover, functional capacity was positively associated with right ventricular parameters.