国際セッション-6

Department of Cardiovascular Medicine, Hokkaido University School of Medicine

This study was aimed to clarify the relation between oxygen delivery and muscle metabolism after exercise and examine their contribution to exercise intolerance in patients with chronic heart failure (CHF). Eight patients with CHF and 8 normal controls (NL) underwent right calf plantar flexion at a constant workload. During recovery from exercise, oxygenated hemoglobin (oxyHb) and phosphocreatine (PCr) in calf muscle were measured. Time constants of oxyHb (τoxyHb) and PCr (τPCr）recovery were significantly longer in CHF (τoxyHb: 48.6±7.6 vs 28.5±8.3, τPCr: 78.9±39.2 vs 35.3±7.1 sec, p<0.01, CHF vs NL). τPCr was significantly greater thanτoxyHb in CHF, while these were consistent in NL. Both time constants, especially τoxyHb was closely related with anaerobic threshold (r=0.80, p<0.05) and peak oxygen uptake (r=0.67, p<0.05). Significantly slower recovery in PCr than in oxyHb in CHF indicated that Hb resaturation is not an only limiting factor in PCr resynthesis. Muscle PCr recovery may depend on the capacity of oxygen utilization other than oxygen delivery in CHF.