EFFECTS OF EXERCISE TRAINING AFTER MYOCARDIAL-INFARCTION ON MUSCULAR METABOLISM VALUE OF PHOSPHORUS 31 NMR-SPECTROSCOPY

International audienceAbstract: P 31 NMR spectroscopy is a recent technique which allows a non-invasive and direct analysis of oxidative metabolism and pH changes, an indicator of acidosis due to lactic acid accumulation in the skeletal muscles. The authors investigated oxidative muscular metabolism of the sural triceps in 10 patients after myocardial infarction by performing a study after the acute phase and repeating the study after a programme of physical training. At rest, there were no significant differences. On the other hand, for the same level of maximal effort, the depletion in phosphocreatinine (PCr) and the accumulation of inorganic phosphate (Pi) were significantly lower after physical training: the PCr/PCr + Pi increased from 0.467 +/- 0.179 to 0.538 +/- 0.20 (p < 0.02) and the Pi/PCr ratio decreased from 1.570 +/- 1.440 to 1.181 +/- 1.069 (p < 0.05). The pH at the same level of maximal exercise did not change significantly between the two periods : 6.85 +/- 0.16 vs 6.88 +/- 0.15 (NS). The peak oxygen consumption (VO2) measured during bicycle ergometry increased significantly from 23.4 +/- 10.5 to 28.3 +/- 12.14 ml/min/kg after exercise training (p < 0.01). In addition, a correlation was observed between the improvement of the peripheral parameters (PCr/PCr + Pi) and the increase in V02 Max (r = 0.757, p < 0.01). The authors' results confirm the effects of physical training on oxidative metabolisms of the peripheral muscles and its influence on improvement of global performance of coronary patients