Pectus Excavatum in an Adolescent Swimmer: Integrating Thoracic Morphology and Cardiopulmonary Exercise Testing

Background and Objectives: Pectus excavatum (PE) alters thoracic geometry and may affect cardiac filling and respiratory mechanics. However, anatomical severity does not necessarily lead to functional limitations. This case study examined the integrated physiological response from rest to maximal exercise and recovery in an asymptomatic, competitive adolescent swimmer with PE. Methods: A 16-year-old male competitive swimmer with asymmetric pectus excavatum (Park type 2A; Haller index 3.3) underwent pulmonary function testing and resting two-dimensional echocardiography, as well as cardiopulmonary exercise testing. Results: From rest to maximal exercise, VO₂ increased approximately 5.9-fold, from 576 to 3378 mL·min^-1 (45.0 mL·kg^-1·min^-1; 92% predicted; AT: 41.2 mL·kg^-1·min^-1), while oxygen pulse increased from 6.0 to 17.9 mL O₂·beat^-1 (AT: 17.0 mL O₂·beat^-1) and OB from 30.3 to 91.3 mL O₂·breath^-1 (AT: 83.5 mL O₂·breath^-1). PQR was 5.05 at rest and 5.11 beats·breath^-1 at peak (AT: 4.92 beats·breath^-1), while peak V_E/MVV reached 56.0% (AT: 48.6%). Pulmonary function testing showed a forced vital capacity at 120% of predicted, forced expiratory volume in one second at 119% of the predicted value and maximal inspiratory pressure was 120% of the predicted value. Resting echocardiography revealed preserved left ventricular longitudinal myocardial deformation (GLS -21.8%) and a transmitral E/A ratio of 1.46. Conclusions: Despite having a thoracic deformity, the athlete demonstrated preserved resting function and an integrated cardiopulmonary response to maximal exercise, with no ventilatory limitations.