目的 探讨二维斑点追踪成像技术在评估甲型流感相关心肌炎患儿左室功能和室壁运动障碍中的价值。方法 选取30例甲流相关心肌炎患儿作为病例组，门诊正常体检患儿33例作为正常对照组，对其进行常规超声检查，并运用二维斑点追踪技术评价心功能及左室整体纵向应变，进行对比分析。结果 30例心肌炎患儿年龄、体表面积、左心室舒张末期内径（LVIDd）、舒张末期室间隔厚度（IVSd）、舒张早期与舒张晚期二尖瓣血流速度比值（E/A）、CK-MB指标与正常对照组差异无统计学意义（P>0.05），病例组心率、血hsTnI指标高于对照组，左室射血分数LVEF、舒张早期二尖瓣环运动速度的比值（E/E’）以及左室整体收缩期应变峰值（GLPS）均低于对照组，差异有统计学意义（P<0.05）。GLPS与LVEF呈显著的正相关，与IVSd呈显著的负相关，但与LVIDd、E/A、E/E’以及血hsTnI、CK-MB及心电指标相关性不明显。GLPS诊断小儿甲流相关心肌炎的最佳阈值为-19.9 %。结论 2D-STE的左室长轴应变可较准确反映甲流病毒感染所致的心肌炎患儿的左室功能变化，可作为甲流相关心肌炎的早期诊断、随访及预后评估的一种简便安全、可靠的实用新手段。

Objective To evaluate left ventricular function and ventricular wall motion disorder by two-dimensional speckle tracking echocardiography (2D-STE) in children with influenza A-related myocarditis. Methods Thirty children with influenza A-related myocarditis were selected as the case group, and 33 children who came in for routine check-ups were used as the normal control group. Routine ultrasonography was performed on both groups, and two-dimensional speckle tracking technology was used to evaluate cardiac function and global longitudinal strain of the left ventricle. Comparative analysis was conducted between the two groups. Results There was no significant difference in age, body surface area, end-diastolic left ventricular diameter (LVIDd), diastolic interventricular septal thickness (IVSd), early diastolic and late diastolic mitral flow velocity ratio (E/A) and CK-MB between the case group and the normal control group (P>0.05). Compared with the normal control group, the heart rate and hsTnI level were higher, and the left ventricular ejection fraction (LVEF), ratio of early diastolic mitral annulus velocity (E/E') and left ventricular global systolic strain peak (GLPS) were lower in the case group, and the differences were statistically significant (P<0.05). GLPS was positively correlated with LVEF and negatively correlated with IVSd, but not significantly correlated with LVIDd, E/A, E/E’, hsTnI, CK-MB and electrocardiographic parameters. The optimal cutoff value of GLPS for the diagnosis of influenza A-related myocarditis in children was -19.9 %. Conclusions Left ventricular long-axis strain of 2D-STE can accurately reflect the changes of left ventricular myocardial mechanical properties in children with myocarditis caused by influenza A virus infection. It can be used as a simple, safe, reliable and practical new means for early diagnosis, follow-up and prognosis evaluation of influenza A-related myocarditis.