Exercise-induced hypoxemia and cardiac arrhythmia in cystic fibrosis

Abstract

Background: Physical activity has become part of the therapy of patients with cystic fibrosis (CF) despite possible risks. The objectives of this study were to identify predictors of hypoxemia and to search for cardiac arrhythmia during exercise.

Methods: The data of 75 patients (12 to 41 years old) with CF who underwent a standardized incremental exercise test on a cycle ergometer was analyzed. Oxygen saturation (SpO(2)) and ECG were monitored. The results were related to spirometric and SpO(2) measurements at rest.

Results: During exercise, 17 patients suffered from significant desaturations (SpO(2)<90%). SpO(2) at peak exercise was independently related to SpO(2) at rest and 1/FEV1 (multiple regression R(2)=0.63). Five patients demonstrated ventricular arrhythmias during exercise. No unambiguous prediction of exercise-induced hypoxemia or cardiac arrhythmia was possible.

Conclusion: In order to detect all patients with exercise-induced hypoxemia and cardiac arrhythmia, an incremental exercise test to volitional fatigue must be performed.