Supplementary Material for: Characteristics of Children with Acute Rheumatic Carditis from a High-Incidence Region: Importance of Unexplained Worsening of Functional Class

<b><i>Background:</i></b> Acute rheumatic fever (ARF) and acute rheumatic carditis (ARC) continue to be a major public health problem in developing countries. <b><i>Objective:</i></b> To study the characteristics of children with ARC being treated at a tertiary centre. <b><i>Methods and Results:</i></b> We studied 126 children (mean age 10.4 ± 2.3 years, range 5–15 years, 60% males) diagnosed with ARC by treating cardiologists. Most had lower socio-economic status. Fifty of 126 (40%) presented with a first episode of ARC. Joint symptoms were present in 29% and fever in 25%. Only 2.4% had subcutaneous nodules and none had erythema marginatum or chorea. Fifty-one percent presented in NYHA class II and 29% in NYHA class III or IV. Tachycardia and heart failure were present in 53% and 21%, respectively. Recent worsening of NYHA class (dyspnoea) was the commonest feature (48%). Laboratory investigations showed raised antistreptolysin O titres (&gt;333 units) in only 36.7% of patients. Raised C-reactive protein (CRP) was present in 70%, while raised erythrocyte sedimentation rate was found in only 37% of patients. On the basis of above findings, the modified Jones criteria (2015) for the diagnosis of ARF were satisfied only in 46% of children. Echocardiography showed mitral valve thickening in 77% and small nodules on the tip of the leaflets in 43% (27 and 8%, respectively for aortic valve). Left ventricular ejection fraction was &lt;50% in only 3 patients. The dominant valve lesion was mitral regurgitation (MR) (present in 95% of patients; severe in 78%, moderate in 15%), while aortic regurgitation was present in 44% (severe in 14%). <b><i>Conclusions:</i></b> The criteria are often not satisfied by patients being treated for ARC. Recent unexplained worsening of dyspnoea, young age, significant MR, echocardiographic nodules, and elevated CRP are important indicators.

**背景**：急性风湿热（Acute rheumatic fever, ARF）与急性风湿性心肌炎（Acute rheumatic carditis, ARC）仍是发展中国家面临的重大公共卫生问题。**目的**：探讨三级医疗中心收治的急性风湿性心肌炎患儿的临床特征。**方法与结果**：本研究纳入126例经接诊心血管专科医师确诊为急性风湿性心肌炎的患儿，平均年龄为10.4±2.3岁，年龄范围5~15岁，男性占比60%。多数患儿社会经济地位偏低。其中50例（40%）为首次罹患急性风湿性心肌炎。29%的患儿存在关节症状，25%伴有发热。仅2.4%的患儿出现皮下结节，无一例出现边缘性红斑或舞蹈症。51%的患儿就诊时纽约心脏协会（New York Heart Association, NYHA）心功能分级为Ⅱ级，29%为Ⅲ级或Ⅳ级。心动过速与心力衰竭的患儿占比分别为53%与21%。近期出现纽约心脏协会心功能分级恶化（即呼吸困难加重）是最常见的临床表现（占比48%）。实验室检查结果显示，仅36.7%的患儿抗链球菌溶血素O滴度升高（＞333单位）。70%的患儿C反应蛋白（C-reactive protein, CRP）水平升高，而仅37%的患儿红细胞沉降率升高。基于上述结果，仅46%的患儿符合2015年修订的琼斯（Jones）急性风湿热诊断标准。超声心动图检查显示，77%的患儿存在二尖瓣增厚，43%的患儿瓣膜尖端可见小结节（主动脉瓣受累者分别占27%与8%）。仅3例患儿的左心室射血分数＜50%。主要瓣膜病变为二尖瓣反流（mitral regurgitation, MR），95%的患儿存在该病变，其中78%为重度反流，15%为中度反流；主动脉瓣反流的患儿占比为44%，其中14%为重度反流。**结论**：因急性风湿性心肌炎收治的患儿往往不符合急性风湿热的诊断标准。近期不明原因的呼吸困难加重、低龄、重度二尖瓣反流、超声心动图可见瓣膜结节以及C反应蛋白升高，均为重要的临床提示指标。