TY - JOUR
T1 - Short-term exercise training improves the cardiovascular response to exercise in the postural orthostatic tachycardia syndrome
AU - Shibata, Shigeki
AU - Fu, Qi
AU - Bivens, Tiffany B.
AU - Hastings, Jeffrey L
AU - Wang, Wade
AU - Levine, Benjamin D
PY - 2012/8
Y1 - 2012/8
N2 - • Recent studies have suggested the presence of cardiac atrophy as a key component of the pathogenesis of the postural orthostatic tachycardia syndrome (POTS), similar to physical deconditioning; exercise intolerance is associated with a reduced stroke volume (SV) in POTS which may be the cause of the high heart rate (HR) at rest and during exercise. • We determined whether physical 'reconditioning' with exercise training improves exercise performance in POTS. • A lower SV resulted in a higher HR in POTS at any given oxygen uptake during exercise while the cardiac output - relationship remained normal. was lower in POTS than healthy sedentary controls. • After 3 months of training in POTS, HR became lower at any given due to increased SV without changes in the - relationship. increased due to increased peak SV, and was proportional to total blood volume. HR recovery from exercise was faster after training than before training. • Thus, exercise training improves physical fitness and cardiovascular responses during exercise in POTS. Recent studies have suggested the presence of cardiac atrophy as a key component of the pathogenesis of the postural orthostatic tachycardia syndrome (POTS), similar to physical deconditioning. It has also been shown that exercise intolerance is associated with a reduced stroke volume (SV) in POTS, and that the high heart rate (HR) observed at rest and during exercise in these patients is due to this low SV. We tested the hypotheses that (a) circulatory control during exercise is normal in POTS; and (b) that physical 'reconditioning' with exercise training improves exercise performance in patients with POTS. Nineteen (18 women) POTS patients completed a 3 month training programme. Cardiovascular responses during maximal exercise testing were assessed in the upright position before and after training. Resting left ventricular diastolic function was evaluated by Doppler echocardiography. Results were compared with those of 10 well-matched healthy sedentary controls. A lower SV resulted in a higher HR in POTS at any given oxygen uptake during exercise while the cardiac output - relationship was normal. was lower in POTS than controls (26.1 ± 1.0 (SEM) vs. 36.3 ± 0.9 ml kg -1 min -1; P < 0.001) due to a lower peak SV (65 ± 3 vs. 80 ± 5 ml; P= 0.009). After training in POTS, HR became lower at any given due to increased SV without changes in the - relationship. increased by 11% (P < 0.001) due to increased peak SV (P= 0.021) and was proportional to total blood volume. Peak HR was similar, but HR recovery from exercise was faster after training than before training (P= 0.036 for training and 0.009 for interaction). Resting diastolic function was mostly normal in POTS before training, though diastolic suction was impaired (P= 0.023). There were no changes in any Doppler index after training. These results suggest that short-term exercise training improves physical fitness and cardiovascular responses during exercise in patients with POTS.
AB - • Recent studies have suggested the presence of cardiac atrophy as a key component of the pathogenesis of the postural orthostatic tachycardia syndrome (POTS), similar to physical deconditioning; exercise intolerance is associated with a reduced stroke volume (SV) in POTS which may be the cause of the high heart rate (HR) at rest and during exercise. • We determined whether physical 'reconditioning' with exercise training improves exercise performance in POTS. • A lower SV resulted in a higher HR in POTS at any given oxygen uptake during exercise while the cardiac output - relationship remained normal. was lower in POTS than healthy sedentary controls. • After 3 months of training in POTS, HR became lower at any given due to increased SV without changes in the - relationship. increased due to increased peak SV, and was proportional to total blood volume. HR recovery from exercise was faster after training than before training. • Thus, exercise training improves physical fitness and cardiovascular responses during exercise in POTS. Recent studies have suggested the presence of cardiac atrophy as a key component of the pathogenesis of the postural orthostatic tachycardia syndrome (POTS), similar to physical deconditioning. It has also been shown that exercise intolerance is associated with a reduced stroke volume (SV) in POTS, and that the high heart rate (HR) observed at rest and during exercise in these patients is due to this low SV. We tested the hypotheses that (a) circulatory control during exercise is normal in POTS; and (b) that physical 'reconditioning' with exercise training improves exercise performance in patients with POTS. Nineteen (18 women) POTS patients completed a 3 month training programme. Cardiovascular responses during maximal exercise testing were assessed in the upright position before and after training. Resting left ventricular diastolic function was evaluated by Doppler echocardiography. Results were compared with those of 10 well-matched healthy sedentary controls. A lower SV resulted in a higher HR in POTS at any given oxygen uptake during exercise while the cardiac output - relationship was normal. was lower in POTS than controls (26.1 ± 1.0 (SEM) vs. 36.3 ± 0.9 ml kg -1 min -1; P < 0.001) due to a lower peak SV (65 ± 3 vs. 80 ± 5 ml; P= 0.009). After training in POTS, HR became lower at any given due to increased SV without changes in the - relationship. increased by 11% (P < 0.001) due to increased peak SV (P= 0.021) and was proportional to total blood volume. Peak HR was similar, but HR recovery from exercise was faster after training than before training (P= 0.036 for training and 0.009 for interaction). Resting diastolic function was mostly normal in POTS before training, though diastolic suction was impaired (P= 0.023). There were no changes in any Doppler index after training. These results suggest that short-term exercise training improves physical fitness and cardiovascular responses during exercise in patients with POTS.
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U2 - 10.1113/jphysiol.2012.233858
DO - 10.1113/jphysiol.2012.233858
M3 - Article
C2 - 22641777
AN - SCOPUS:84864320132
SN - 0022-3751
VL - 590
SP - 3495
EP - 3505
JO - Journal of Physiology
JF - Journal of Physiology
IS - 15
ER -