Effects of Deep Breathing Exercises Two Months After Cardiac Surgery

Hypothesis: Deep breathing exercises performed during the first two months after cardiac surgery, will improve pulmonary function and patient-perceived quality of recovery. Specific aim: To evaluate the effectiveness of breathing exercises performed with a mechanical device for positive expiratory pressure during the first two months after cardiac surgery compared to a control group performing no breathing exercises. Design: A prospective, randomized, controlled two-center study.