Objective To explore the application value of peak strain dispersion (PSD) for assessment of left ventricular (LV) synchronization in patients with esophageal carcinoma before and after radiotherapy. Methods A total of 60 patients with esophageal carcinoma who received chest radiotherapy for the first time in the Northern Jiangsu People′s Hospital from October 2017 to July 2018 were enrolled in this study. Another 25 age-and sex-matched health volunteers at the same period served as control. Routine echocardiography examinations were performed before, in the middle of (after 14 times of radiotherapy), after and in 1 month after radiotherapy, and the obtained parameters were compared between the two groups. SPSS statistics 25.0 was used to analyze the data. Spearman correlation analysis was employed for correlation analysis. Results There were no significant differences in the echocardiographic parameters before and in the middle, end and in 1 month after radiation (P>0.05). In the above time points, the time to peak longitudinal strain (TTPLS) in basal segment was (361.0±29.0), (376.6±35.1), (382.7±33.8) and (370.6±36.9) ms, respectively, maximum difference of TTPLS (Tls-dif) in basal segment was (92.86±7.39), (105.67±25.18), (124.57±31.61) and (110.98±29.93) ms,respectively, and it in middle segments was (66.57±23.64), (87.56±20.13), (101.57±17.48) and (84.32±23.81) ms. The differences were gradually extended from the middle to the 1 month after radiotherapy (P<0.05). Compared with the end of radiotherapy, the above parameters showed a shortening trend in 1 month after radiotherapy (P<0.05). Compared with the values before radiation,PSD was increased gradually from the middle to the 1 month after radiotherapy [(33.20±7.65) vs (36.83±8.20) vs (40.91±8.36) vs (38.53±9.89) ms], while the absolute value of global longitudinal peak strain (GLPS) was decreased gradually (P<0.05). The PSD and GLPS values gradually recovered to the pre-radiotherapy levels in 1 months after radiation when compared with those at the end of radiotherapy (P<0.05). Spearman correlation analysis indicated that the absolute value of GLPS was negatively correlated with PSD (r=-0.61, P<0.01). Conclusion PSD can be used to evaluate the left ventricular contraction synchronization in esophageal carcinoma patients before and after radiotherapy, and is helpful for monitoring their cardiac function and timely adjusting radiotherapy regimen in clinical practice.