Whereas none of our subjects claimed to have dyspnea at rest, during control exercise at 60% of WLmax, dyspnea scores ranged between 3.5 and 9. With PLB, breathlessness increased in four of the eight patients, was relatively unaltered in two patients, and decreased in two patients (Fig 1).
Effect of PLB on Breathing Pattern
Individual and average values for breathing pattern variables at rest and during exercise are shown in Tables 2 and 3, respectively. PLB prolonged total breath duration, slowed breathing frequency (fB), and increased Vt both at rest and during exercise.