The evaluation of left ventricular function change in younger infants with Kawasaki disease by Tissue doppler imaging

AIM To observe the characteristics in younger infants with KD by TDI. METHODS 125 KD patients were consecutively selected, and divided into two groups, ≤6 months group and >6 months group. 28 cases were included in the ≤6 months group, while 97 cases were in the >6 months group. The e’sept (the mitral annular velocity of septal during early diastolic period), e’lat (the mitral annular velocity of lateral left ventricle during early diastolic period) and septal TDI-Tei index (the sum of the isovolumetric contraction and relaxation times divided by the ejection time) in before IVIG administration, 6 weeks after IVIG administration, and 12 weeks after IVIG administration were measured by TDI, and were compared with each other during different phases. RESULTS ≤6 months group had a higher incidence of coronary artery lesions than >6 months group (32% vs. 24%), and the damage degree was more serious. ≤6 months group had a much lower value of e’lat and e’sep and a much higher value of E/e’lat and E/e’sep than group B in the first two phases (P<0.05). There were no significant differences in e’lat and e’sep between the two groups in the last phase, but a higher value of E/e’sep in ≤6 months group (P<0.05). There was a higher TDI-Tei index in ≤6 months group than >6 months group during the first two phases (P<0.05), and no signficant difference in the last phase. In ≤6 months group, compared to before IVIG administration, e’lat, e’sep, E/A, E/e’lat, E/e’sep and TDI-Tei index of 12 weeks after IVIG administration begun to recover (P<0.05), but there was no significant difference between the time before IVIG administration and the time of 12 weeks after IVIG administration. In >6 months group, there were no significant differences among the three phases. CONLUSION There is a high incidence of coronary artery lesions in younger infants, and the degree of injury can be more serious. The left ventricular diastolic function of such patients can significantly decrease and the recovery time is longer. With the significantly early rise in E/e’sept, E/e’lat, TDI-Tei index may be used to assist in the diagnosis of such disease.