Effect of pectus excavatum deformity on cardiorespiratory fitness in adolescent boys

Objective: To determine the magnitude of the effects of pectus excavatum deformity on endurance fitness and cardiorespiratory functional reserve in adolescent boys. Design: Cross-sectional comparison of cardiac and ventilatory variables at rest and during a maximal cycle exercise test. Setting: Pediatric exercise-testing laboratory Participants: Twelve boys (mean +/- SD age, 14.1 +/- 1.8 years; age range, 11.8-18.0 years) with moderate-to-severe pectus excavatum deformity (mean +/- SD Haller index, 3.95 +/- 0.88) and 20 control boys (mean SD age, 12.5 +/- 0.4 years; age range, 12.1-13.5 years) without musculoskeletal deformity. Main Outcome Measures: Endurance fitness (physical work capacity); respiratory rate, tidal volume, and minute ventilation; and cardiac output and stroke volume by Doppler echocardiography. Results: Patients with pectus deformity had significantly lower endurance fitness than controls (meant +/- SD physical work capacity, 2.60 +/- 0.28 W center dot kg(-1) vs 3.11 +/- 0.45 W center dot kg(-1)) and reduced mean SD values for maximal cardiac index (10.6 +/- 1.6 L center dot min(-1) vs 12.0 +/- 2.2 L center dot min(-1)) and peak tidal volume (3.02 +/- 0.27 mL center dot kg(-1) center dot 10(-2) Vs 3.46 +/- 0.30 mL center dot kg(-1) center dot 10(-2)). However, considerable overlap was observed in these values between the 2 groups. Conclusions: As a group, boys with pectus excavatum deformity have lower endurance fitness than controls, and this is associated with reduced cardiac output and tidal volume responses to exercise. However, the wide variability of these measures makes it difficult to assign pectus deformity as a cause of exercise intolerance in individual patients.