EXERCISE TOLERANCE, PULMONARY FUNCTION, RESPIRATORY MUSCLE STRENGTH, AND QUALITY OF LIFE IN CHILDREN AND ADOLESCENTS WITH RHEUMATIC HEART DISEASE

ABSTRACT Objective: Despite the high prevalence of rheumatic heart disease in Brazil, the occurrence of functional impairment in children and adolescents with rheumatic heart disease is not clear. The aim of this study was to evaluate exercise tolerance, respiratory muscle strength, lung function, and quality of life of children and adolescents with rheumatic heart disease. Methods: Cross-sectional study, conducted from August to December 2014 with children and adolescents with rheumatic heart disease aged 8 to 16 years. The participants, after completing the socioeconomic, clinical, and quality of life questionnaires were tested by spirometry, manovacuometry and in a 6-minute walk test. The variables and their reference values were compared using the paired Student’s t-test. Comparisons between predicted and observed walking distance were done also by Student’s t-test, consdiering the categorization of the participants. Correlations between these differences and quantitative variables were assessed by Pearson’s coefficient, being significant p<0.05. Results: All 56 participants had a walked distance lower than predicted (p<0.001). The differences between predicted and observed distances were positively correlated with the baseline heart rate (r=0.3545; p=0.007). Expiratory muscle strength was also lower than the predicted values (p<0,001). Regarding quality of life assessment, the mean scores were 70, 77 and 67% for general, physical, and psychosocial aspects, respectively. Conclusions: Children and adolescents with rheumatic heart disease have reduced exercise tolerance, which is related to their higher baseline heart rate; they also show impaired expiratory strength and quality of life.

摘要
目的：尽管风湿性心脏病在巴西的患病率较高，但罹患该病的儿童及青少年出现功能损害的情况尚不明确。本研究旨在评估风湿性心脏病儿童及青少年的运动耐量、呼吸肌肌力、肺功能与生活质量。
方法：本研究为横断面研究，于2014年8月至12月开展，纳入8~16岁的风湿性心脏病儿童及青少年作为研究对象。参与者完成社会经济状况、临床资料及生活质量（quality of life）相关问卷后，依次接受肺量测定（spirometry）、呼吸肌压力容量测定（manovacuometry）以及6分钟步行试验（6-minute walk test）。采用配对Student’s t检验（paired Student’s t-test）对各变量及其参考值进行比较；同时根据受试者的分类情况，采用Student’s t检验比较预测步行距离与实际步行距离的差异。通过Pearson相关系数（Pearson’s coefficient）评估上述差值与定量变量间的相关性，以p<0.05作为显著性检验阈值。
结果：本研究共纳入56名参与者，所有受试者的实际步行距离均低于预测值（p<0.001）。预测步行距离与实际步行距离的差值与基线心率呈正相关（r=0.3545；p=0.007）。呼气肌肌力同样低于预测参考值（p<0.001）。生活质量评估结果显示，总体、生理及社会心理维度的平均得分分别为70%、77%与67%。
结论：风湿性心脏病儿童及青少年的运动耐量降低，且该现象与其基线心率升高相关；同时其呼气肌肌力与生活质量亦存在受损表现。