Pectus excavatum (PE) is a relatively common congenital deformity of the anterior chest wall associated with reduced exercise capacity. Uncertainty exists over the nature of physiologic impairment in PE. Evidence suggests that myocardial compression exerted by the displaced sternum on the right heart chambers, disables the ability of the heart to augment stroke volume during exercise. This case study describes the evaluation of an athletic 20 year old Caucasian male, lifelong non-smoker, with severe pectus deformity and previous fixation procedure to repair a sternal fracture. The patient performed an incremental cycle ergometer exercise test to determine the etiology of his dyspnea with exertion. The patient demonstrated normal work output and normal aerobic capacity but displayed dynamic hyperinflation. Mechanical restriction of tidal volume expansion appeared to be the major contributors to exercise limitation. These results are compared and contrasted with similar cases reported in the literature.

• Pectus excavatum (PE) is a relatively common phenomenon affecting approximately 1 in 300 births, with a 9:1 ratio of male to female rate of incidence.

• The etiology or exercise limitation is most frequently due to cardiovascular limitation due to the compression of the sternum upon the myocardium, impairing the ability to augment stroke volume.

• The Pectus Severity Index (PSI) is a useful indicator of pectus severity.

• Cardiopulmonary exercise testing provides useful data to distinguish between cardiovascular limitation, ventilatory limitation, or deconditioning in the evaluation of PE.

• In this case study, ventilatory limitation was due to the mechanical restriction of the thoracic cavity.