[Value of pulmonary hemodynamic exploration during muscular exercise in chronic bronchitis?]

The value of pulmonary haemodynamic tests during physical exercise in chronic bronchitis was shown by the comparison of two groups of patients. In the first group (n=24) the PAP during exercise is lower than 30 torr. In the second it was over 30 torr. The PAP at rest was always lower than 20 torr. The load was 40 to 50 watts, i.e. an average O2 consumption of 500-600 ml.mm-1 m-2. The cardiac output doubled on average in exercise. Both groups varied markedly in their PAP at rest: 13.6 +/- 1.7 torr for the first group and 15.8 +/- 2.4 for the second (p less than 0.001). In fact differences in pressure during exercise (I=25.0 +/- 3.4 torr; II=39.6 +/- 7.4 torr, p less than 0.001) could be explained mainly by the differences of pulmonary vascular resistances (I=0.91 +/- 0.37; II=1.47 +/- 0.61, p less than 0.005): they tended to fall during effort in the first group and increased slightly in the second; and by the much higher increase in the pulmonary "capillary" pressure during exercise in the second group (I=12.5 +/- 4.4 torr; II=19.7 +/- 72 torr, p less than 0.001). The cardiac output during rest and exercise was equal in both groups. The haemo-dynamic "recovery delay" was much higher in the second group. The spirographic shortage was on the whole identical in both groups. PaO2 on average was higher in group I (p less than 0.05) where it improved during exercise (p less than 0.01). The PaO2 of the second group did improve during exercise. The haemodynamic differences were concomitant with the differences in gas exchanges during effort, of well known prognostic significance. As the "foretelling" of PAP in effort from the PAP at rest was quite poor, it appeared that haemodynamic test in effort has a real value in contributing efficiently to the differenciation of the degree in severeness. The threshold of 30 torr for PAP in exercise (and for the load mentioned above) seemed a good discriminating factor.