Muscular blood flow response to submaximal leg exercise in normal
subjects and in patients with heart failure.
Isnard, Richard, Philippe Lechat, Hanna Kalotka, Hafida Chikr, Serge
Fitoussi, Joseph Salloum, Jean-Louis Golmard, Daniel Thomas, Michel
Komajda.
Service de Cardiologie et de Pharmacologie clinique, Association
Claude Bernard. Centre de Recherches Cardiologiques,
H[circumflex]opital Piti[acute]e-Salp[circumflex]etri[grave]ere,
PARIS, Institut Terrapharm, D[acute]epartement de Biostatistiques et
d'Informatique
APStracts 3:0403A, 1996.
Blood flow to working skeletal muscle is usually reduced during
exercise in patients with congestive heart failure. An intrinsic
impairment of skeletal muscle vasodilatory capacity has been
suspected as a mechanism of this muscle underperfusion during maximal
exercise, but its role during submaximal exercise remains unclear.
Therefore, we studied arterial blood flow in the common femoral
artery by transcutaneous Doppler ultrasonography in 12 normal
subjects and 30 patients with heart failure, at rest and during a
submaximal bicycle exercise. Leg blood flow was lower in patients
than in control subjects at rest (0.29+/-0.14 (SD) vs 0.45+/-0.14
l.min-1, p<0.01), at absolute powers and at the same relative
power (2.171.06 vs 4.391.4 l.min-1, p<0.001). Since mean
arterial pressure was maintained, leg vascular resistance was higher
in patients than in control subjects at rest (407+/-187 vs 247+/-71
mmHg.min.l-1, p<0.01) and at the same relative power (7349 vs
3113 mmHg.min.l-1, p<0.01), but not at absolute powers. Although
the magnitude of increase in leg blood flow corrected for power was
similar in both groups (31+/-10 vs 34+/-10 ml.min-1.W-1), the
magnitude of decrease of leg vascular resistance corrected for power
was higher in patients than in control subjects (5.93.3 versus
1.90.94 mmHg.min.l-1.W-1, p<0.001). These results suggest that
the ability of skeletal muscle vascular resistance to decrease is not
impaired and that intrinsic vascular abnormalities do not limit
vasodilator response to submaximal exercise in patients with heart
failure.
Received 15 April 1996; accepted in final form 2 August 1996.
APS Manuscript Number A355-6.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 19 September 1996