The Importance of Echocardiogram during the Second Week of Illness in Children with Kawasaki Disease.

Objective: To determine the timing of peak coronary artery dilation and the characteristics of patients who present with new-onset coronary artery dilation during the acute phase of Kawasaki disease with an initial normal echocardiogram.

Study Design: This retrospective study analyzed 231 children hospitalized for Kawasaki disease in Hawai'i over a period of 7 years. Clinical and echocardiographic data were collected to calculate the timing of peak z score, and study subjects were compared based on the timing of coronary dilation.

Results: Peak coronary artery dilation was observed on average at 11.5 days from the onset of fever (median 8, IQR 7-13 days). Among study subjects with normal z scores in both coronary arteries during the initial encounter and echocardiogram (n = 164), 16 (10%) developed coronary artery dilation or aneurysm at the second echocardiogram, and 5 (3%) continued to have coronary artery dilation or aneurysm at the convalescent phase.

Conclusions: A repeat echocardiogram during the second week of illness (day 7-14 from fever onset) in patients with normal initial echocardiogram could identify new-onset coronary artery dilation or aneurysm and could be useful in the timely adjustment of antithrombotic or anti-inflammatory therapies.