[Changes in blood volume in the muscles of the thigh and calf during exercise and recovery and their relationships to exercise tolerance in patients with cardiac disease].

OBJECTIVES

This study compared the blood-volume changes and recovery in the thigh and calf during leg exercise and evaluated the relationships to exercise tolerance.

METHODS

The peak oxygen uptake and total hemoglobin level(blood-volume index), oxyhemoglobin level, and deoxyhemoglobin level in the thigh and calf were measured by near-infrared spectroscopy during leg ergometer exercise and recovery in 13 patients with cardiac disease(mean age: 66 +/- 6 years, left ventricular ejection fraction: 31-82%).

RESULTS

There was no significant difference between the increase in blood-volume index during exercise in the thigh and that in the calf. The increase in the blood-volume index during recovery in the calf was significantly greater than that in the thigh, mainly due to the difference in deoxyhemoglobin levels. There were no positive relationships between the peak oxygen uptake and increases in blood-volume index except for the increase in blood-volume index in the thigh during exercise(r = 0.73).

CONCLUSIONS

There was no significant difference between the increase in blood-volume index in the thigh and that in the calf during exercise, whereas the increase in blood-volume index during recovery in the calf was significantly greater than that in the thigh in patients with cardiac disease. Only the increase in the blood-volume index in the thigh during exercise is related to the leg-exercise tolerance in patients with cardiac disease.