Cardiopulmonary exercise test indices of respiratory buffering before and after aerobic exercise training in women with pulmonary hypertension: Differentiation by magnitudes of change in six-minute walk test performance.
While aerobic exercise training (AET) has generally been shown to improve 6-min walk test (6MWT) distance (6MWD) in patients with pulmonary hypertension (PH), a substantial number of patients appear to adapt differently, with minimal or even negative changes in 6MWT distance being reported.


PURPOSE
To compare post-aerobic exercise training adaptations in cardiorespiratory functional capacity across three groups of patients with PH: those with high (HI), low (LI) and negative (NEG) post-training increases in 6MWD.


METHODS
Participants were 25 females (age 54 ± 11 years; BMI 31 ± 7 kg/m2) who completed a vigorous, 10-week, thrice weekly, supervised treadmill walking exercise program. Cardiopulmonary exercise tests (CPET) and 6MWT were completed before and after training. Ten of the 25 participants were classified as HI (range = 47-143 m), 11 were classified as LI (range = 4-37 m) and 4 were classified as NEG (range = -17 to -53 m).


RESULTS
Peak CPET duration, WR and time to anaerobic threshold (AT) were significantly higher (p < 0.05) after training in both the LI and HI groups but not in the NEG group. There was a significant improvement in VE/VCO2 (p = 0.042), PETCO2 (p = 0.011) and TV (p = 0.050) in the HI group after training, but not in the NEG or LI group.


CONCLUSION
These findings suggest that sustained ventilatory inefficiency and restricted respiratory buffering may mediate exercise intolerance and impede the ability to adapt to exercise training in some patients with PH.
['Morris|Z V|ZV|', 'Chin|L M K|LMK|', 'Chan|L|L|', 'Guccione|A A|AA|', 'Ahmad|A|A|', 'Keyser|R E|RE|']
D000328:Adult D000368:Aged D015444:Exercise D005080:Exercise Test D005081:Exercise Therapy D017079:Exercise Tolerance D005260:Female D006801:Humans D006976:Hypertension, Pulmonary D008875:Middle Aged D016896:Treatment Outcome D000070857:Walk Test
Aerobic exercise training Pulmonary hypertension Six-minute walk test