Objective: We aimed to investigate the hypothesis that the presence of left ventricular (LV) dyssynchrony in children with acute rheumatic fever (ARF) children may be a predictor of latent rheumatic carditis. Methods: Eighty-nine children with ARF and 45 healthy control children were included the study. LV dyssynchrony was investigated by color-coded tissue Doppler imaging. Results: LV dyssynchrony parameters including Ts-SD- 12, Ts-12, Ts-SD- 6, and Ts-6 were found to be prolonged in children with ARF than in controls (P < .001). We found that 45.2% in children with ARF without carditis had LV dyssynchrony (Ts-SD- 12 ≥ 34.4 ms), while 63.4% in children with ARF with carditis had LV dyssynchrony. Follow-up analysis demonstrated that children with arthritis and without dyssynchrony had no adverse events (recurrent rheumatic activity, development of valvular diseases; heart failure and atrial fibrillation), while those with LV dyssynchrony had events rate of 40.9% (P < .001). Likewise, children with carditis had event rates of 63.4%. Ts-SD- 12 was found to be correlated with hs-CRP (r = .63; P < .001). Receiver-operating characteristic (ROC) curve analysis showed that a Ts-SD- 12 ≥ 36.5 was the optimal cutoff value in predicting unfavorable outcome in patients with ARF, with a sensitivity of 95% and specificity of 82%. Conclusions: We found that children with ARF without any evidence of carditis had a significant LV systolic dyssynchrony spite of normal EF. LV dyssynchrony in those children had a significant event rates on follow-up. These results highlighted the incremental value of LV dyssynchrony as a marker of subclinical carditis in children with ARF.