Twenty-seven patients and 27 healthy children were entered into the study. Of the 27 participants, 11 (40.7%) were boys. The mean age of the patients and healthy children was 5.56 ± 2.2 and 5.73 ± 3.16 years, respectively. The mean weight of the patients and healthy children was 19.5 ± 6 and 17.4 ± 5.41 kg, respectively. No statistically significant difference between patients and control subjects in terms of gender, age or LVEF (M-mode) was found. Clinicodemographic data can be seen in Table 1. Table 2 includes data on symptoms, KD type, and treatment.

In Table 3, the relationship between GLPS.LAX, GLPS.A4C, GLPS.A2C, and GLPS. Avg with gender, number of symptoms, disease type and treatment was evaluated. Mean GLPS.A4C in boys was significantly lower than girls. Mean GLPS.A4C of girls was − 23.74 ± 2.77, and that of boys was − 20.93 ± 2.06 (P value  = 0.008).

In Table 4, we depict cardiac parameters and regional strain in both genders. LVIDd and LVIDs in boys were significantly upper than girls. The values of segmental strain in mid-anteroseptal, mid-inferoseptal, apical-septal, apical-inferior, apical-lateral, apex were significantly lower in boys (all P value s < 0.05). Other parameters had no differences between two sexes.

In Table 5, we present the mean regional strain between patients with complete and incomplete KD. The mean of segmental strain in basal inferoseptal and apical anterior had a statistically significant difference between the two groups.

The correlation between GLPS.LAX, GLPS.A4C, GLPS.A2C, and GLPS. Avg variables with FS, E percent, LVIDs, and LVIDd was assessed. Based on analyses, only GLPS.A4C has a positive correlation with LVIDs. In other words, an increase of LVIDs increases the patient's GLPS.A4C (P value  = 0.038). There were no statistically significant correlations between other parameters.

In Table 6, the correlation between percent of FS, E percent, LVIDs, and LVIDd with segmental strain was investigated. LVIDd and LVIDs parameters had a significant positive correlation with segmental strain in mid-anteroseptal, mid-inferoseptal, apical anterior, apical inferior, and apex. For one-unit increase in LVIDs, the mentioned parameters increase by 0.47, 0.44, 0.40, 0.53, and 0.44 units, respectively. Also, for one-unit increase in LVIDd, the mentioned parameters increase by 0.40, 0.49, 0.36, 0.58, and 0.42 units, respectively.

In the comparison of different segments, it was found that there is a major difference between the two groups in the basal inferolateral segment, which receives blood from left circumflex artery. However, other cardiac segments had similar conditions. On the other hand, there is no significant difference in global strain between the two groups of patients and healthy children (Tables 7 and 8).