Evaluation of intermittent claudication by near-infrared spectroscopy and air plethysmography *
The usefulness of near-int'rared spectroscopy (NIRS) and air plethysmography (APG) in estimating the severity of intermittent claudication was evaluated. NIRS and APG were performed with a treadmill test in 40 patients who complained of intermittent claudication and 47 juvenile and 10 older people in control subjects. The NIRS probe was positioned on the posterior aspect of calf and the treadmill test was performed with a 12% slope at a speed of 2. 4km/hr for three minutes. The time between the end of exercise and intersection of the curves of recovering oxy-Hb and deoxy-Hb was measured (recovery time : RT). After 30 minutes, resting and postexercise arterial inflow of the extremities was also investigated, and resting arterial inflow divided the volume of lower extremities per 100cm 3 (rAIlndex) and postexercise arterial infow divided the volume of lower extremities per 100cm 3 (eAIIndex) were measured. These indices were compared with Ankle Brachial Index (ABI) and angiographic findings. RT showed a significant inverse correlation with ABI, and rAIlndex and eAIIndex had a significant positive correlation with ABI. All subjects were classified into 4 groups by r-and eAILndexes ; Ⅱa : both r-and eAIIndex> 0. 9 and eAIIndex>rAIIndex, Ⅱ b both r-and eAIIndex>0. 9 and eAIIndex
