RESUMO
BACKGROUND: We explored whether the maximum predicted walking distance, assessed with six-minute walk test (6MWT) and reflecting submaximal functional exercise capacity, is decreased among patients with pectus excavatum (PEX). METHODS: This study comprised a retrospective analysis of patients with PEX who underwent a 6MWT for the assessment of functional capacity. The maximum distance walked was recorded and compared to reference values established for different populations, including a young and healthy South American population. RESULTS: We included 43 patients with PEX who underwent 6MWT. The mean age was 17.8 ± 6.7 years. The mean maximum distance walked was significantly lower than the predicted distance (600.8 ± 67.6 metres vs. 729.8 ± 67.5 metres, p < 0.0001). Using the Enright reference equation including an older reference population, the mean negative difference was higher (PEX patients walked 190.4 ± 78.4 metres less than predicted, p < 0.0001). We also applied the Li et al. reference equation accounting for sex among other variables, detecting a decreased walked distance compared to the gender-adjusted predicted distance (PEX patients walked a mean 222.4 ± 87.4 metres less than predicted, p < 0.0001). Using the Ulrich et al. equation, PEX patients walked a mean 114.2 ± 85.1 metres less than predicted (p < 0.0001). Although of uncertain clinical relevance, there was a significant decrease in the mean oxygen saturation after exercise (baseline 97.4 ± 1.2%, vs. final 96.4 ± 2.1%, p = 0.006). CONCLUSIONS: In this study, we identified a significant reduction in the maximum walked distance among patients with PEX compared to the predicted distance, thus potentially emerging as an unsophisticated means to evaluate and quantify functional exercise capacity.
Assuntos
Tórax em Funil , Coração , Pulmão , Caminhada , Humanos , Tórax em Funil/fisiopatologia , Pulmão/fisiopatologia , Coração/fisiopatologia , Teste de Caminhada , Masculino , Feminino , Saturação de Oxigênio , Criança , Adolescente , Adulto Jovem , Adulto , Fatores de TempoRESUMO
AIMS: Previous studies have demonstrated diverse cardiac manifestations in patients with pectus excavatum (PEX), although mostly addressing morphological or physiological impact as separate findings. Using multimodality imaging, we evaluated the impact of PEX on cardiac morphology and function according to the site of maximum compression, and the effect of exertion and breathing. METHODS AND RESULTS: All patients underwent chest computed tomography, cardiac magnetic resonance (CMR), and stress echocardiography (echo) in order to establish surgical candidacy. We evaluated diastolic function and trans-tricuspid gradient during stress (echo); and systolic function and respiratory-related septal wall motion abnormalities (CMR). Patients were classified according to the site of cardiac compression as type 0 (without cardiac compression); type 1 (right ventricle); and type 2 [right ventricle and atrioventricular (AV) groove]. Fifty-nine patients underwent multimodality imaging, with a mean age of 19.5 ± 5.9 years. Compared with a sex and age matched control group, peak exercise capacity was lower in patients with PEX (8.4 ± 2.0 METs vs. 15.1 ± 4.6 METs, P < 0.0001). At stress, significant differences were found between groups regarding left ventricular E/A (P = 0.004) and e/a ratio (P = 0.005), right ventricular E/A ratio (P = 0.03), and trans-tricuspid gradient (P = 0.001). At CMR, only 9 (15%) patients with PEX had normal septal motion, whereas 17 (29%) had septal flattening during inspiration. Septal motion abnormalities were significantly related to the cardiac compression classification (P < 0.0001). CONCLUSIONS: The present study demonstrated that patients with PEX, particularly those with compression affecting the right ventricle and AV groove, manifest diverse cardiac abnormalities that are mostly related to exertion, inspiration, and diastolic function.