The distribution of the blood flow during exercise in chronic heart failure--compensatory mechanism to the decreased cardiac output.
To evaluate the blood flow distribution during exercise, 51 patients with chronic heart failure underwent ergometer exercise testing measuring cardiac output and leg blood flow. At the given workrate (10 watts and 25 watts) cardiac index (L/min/m2) was significantly lower in NYHA class III patients than class I patients (at 10 watts, 4.08 +/- 1.05 in class I, 4.01 +/- 1.29 in class II and 3.00 +/- 0.89 in class III, p less than 0.05; I vs III), while leg blood flow (L/min/m2) was similar among 3 groups (at 10 watts, 1.19 +/- 0.32, 1.29 +/- 0.25 and 1.16 +/- 0.29, ns). Consequently, residual blood flow (L/min/m2) was significantly lower in class III than class I (at 10 watts, 2.89 +/- .92 and 2.78 +/- 1.27 and 1.84 +/- 0.71, p less than 0.05: I vs III). The results at 25 watts were similar. Serum noradrenaline was significantly higher in class III patients than class I patients at both 10 and 25 watts. We concluded that in severe heart failure, agreater blood flow is distributed to the working leg muscle as compared with less severe heart failure. And such an increased distribution of blood flow to working leg plays a role to compensate an insufficient cardiac output response in patients with severe heart failure.
Yamabe
H
H
First Department of Internal Medicine Kobe University School of Medicine, Japan.
Itoh
K
K
Yasaka
Y
Y
Kakimoto
T
T
Yokoyama
M
M
D000328:Adult; D000368:Aged; D001775:Blood Circulation; D002302:Cardiac Output; D002908:Chronic Disease; D015444:Exercise; D005080:Exercise Test; D006333:Heart Failure / Q000097:blood / Q000503:physiopathology*; D006801:Humans; D007866:Leg / Q000098:blood supply; D008875:Middle Aged; D009132:Muscles / Q000098:blood supply; D009638:Norepinephrine / Q000097:blood; D012039:Regional Blood Flow
D009638:Norepinephrine