Medicine of the Future in America

Exercise Limitation in Patients with Polymyositis: Results (3)

Resting pulmonary function is illustrated in Figure 1. All patients had normal maximum inspiratory pressures. Only one patient (No. 10) had an abnormally low maximum expiratory pressure. Patient 3 had a mild reduction in the TLC, and patients 2 and 10 had mild reductions in diffusing capacity. No patient had evidence of obstructive ventilatory impairment.
Figure 2 illustrates the data during maximal exercise. The maximal work load ranged from 11 to 71 percent of predicted. The mean aerobic capacity or Vo2 max was 57 percent (± 20) but again the individual values were scattered over a wide range. Minute ventilation at maximal exercise, expressed as the percentage of the M Vy suggested the patients did not have a ventilatory limitation to exercise since the Ve/ MW ratio did not exceed 60 percent in any individual. No patient desaturated as measured by pulse oximetry. Despite the trend for patients with pulmonary hypertension to have higher Vd/Vt ratios at end-exercise than those without pulmonary hypertension, this difference did not achieve statistical significance. buy diabetes drugs
Figure 3 illustrates the relationship between the 02 pulse and heart rate achieved at Vo2 max. The majority (nine of 11) of patients stopped exercising because of peripheral muscle fatigue while two (patients 2 and 11) complained of dyspnea. Four patients had normal 02 pulse, as percent predicted. Three of these four patients also had a normal Vo2 max while patient 1 only reached 70 percent of the target heart rate before the onset of peripheral muscle fatigue. Seven patients had a decreased 02 pulse. In five of these seven (patients 3, 4, 8, 10 and 11) the maximal heart rate exceeded 85 percent of predicted, suggesting an impaired stroke volume response and therefore cardiac limitation to exercise. Two others (patients 5 and 7) with a low 02 pulse developed peripheral muscle fatigue prior to reaching their target heart rate.

Figure_1

Figure 1. Resting pulmonary data in patients with polymyositis. Data expressed as percent predicted except for FEV/FVC ratio which is observed percentages. Solid triangles, pulmonary hypertension but no active disease; solid circles, no pulmonary hypertension and no active disease; open triangles, pulmonary hypertension and active disease; open circles, no pulmonary hypertension but active disease.

Figure_2

Figure 2. Exercise data of patients with polymyositis; Vo% max expressed as percent predicted; Ve at maximal exercise expressed as percentage of MW at rest; Vd/Vt at end-exercise. Solid trangles, pulmonary hypertension but no active disease; solid circles, no pulmonary hypertension and no active disease; open triangfes, pulmonary hypertension and active disease; open circles, no pulmonary hypertension but active disease.

Figure_3

Figure 3. Relationship between Os pulse and heart rate (both expressed as percent predicted) at maximal exercise. Solid triangles, pulmonary hypertension but no active disease; solid circles, no pulmonary hypertension and no active disease; open triangles, pulmonary hypertension and active disease; open circles, no pulmonary hypertension but active disease.

This entry was posted in Polymyositis and tagged active disease, polymyositis, pulmonary hypertension.
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