**7.1 Optimisation of imaging modalities**

The primary aim of echocardiography is to identify coronary artery involvement, pericarditis and/or myocarditis. As always, optimising machine settings, using the highest possible frequency transducer and reducing two-dimensional gain and compression can achieve better image quality and resolution. B-mode cine loops and still frame images are necessary to assess coronary artery calibre, along with colour Doppler imaging set at a low Nyquist limit for evaluating normal coronary artery diastolic flow. Sedation may be necessary in children who are too irritable to tolerate a detailed study; our preference is to use 50-100mg/kg of chloral hydrate (max 1g) given orally with heart rate and peripheral oxygen saturation monitoring.

### **7.2 Coronary artery assessment**

Coronary arteries should be assessed in multiple imaging planes before a decision is reached about the presence or absence of coronary artery abnormalities. The parasternal short axis view with or without a clockwise rotation of the transducer allows for imaging of the left coronary artery origin, left anterior descending artery and left circumflex artery, as well as the right coronary artery origin and proximal course. Parasternal long axis views with sweeps between the aorta and pulmonary artery will delineate the left main coronary artery, left anterior descending and circumflex arteries. Subcostal views are helpful for assessing the left circumflex artery and the mid-course of the right coronary artery. Apical four chamber views will show the length of the left circumflex artery and distal right coronary artery in the left and right atrioventricular grooves respectively. Coronary artery measurements should be taken from the inner edge to inner edge of the vessel wall and should not be measured at the level of normal branching.

Echocardiography in Kawasaki Disease 143

Fig. 2. Parasternal short axis echocardiographic image at the level of the mitral valve leaflets

Fig. 3. Parasternal short axis echocardiographic image showing a uniformly dilated

proximal right coronary artery (RCA).

demonstrating an aneurysm of the left anterior descending artery.
