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 (mean +/- SD physical work capacity, 2.60 +/- 0.28 W . kg(-1) vs 3.11 +/- 0.45 W . kg(-1)) and reduced mean +/- SD values for maximal cardiac index (10.6 +/- 1.6 L . min(-1) vs 12.0 +/- 2.2 L . min(-1)) and peak tidal volume (3.02 +/- 0.27 mL . kg(-1) . 10(-2) vs 3.46 +/- 0.30 mL . kg(-1) . 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.