[Visualization of peripheral left coronary aneurysms in Kawasaki disease by subcostal two-dimensional echocardiography].

: Our previous study provided a new two-dimensional echocardiographic technique for detecting peripheral "right" coronary artery aneurysms in Kawasaki disease using a subcostal approach. In the present paper, we presented an additional study for detecting peripheral "left" coronary artery aneurysms. Because the left anterior descending artery runs along the anterior interventricular sulcus and the left circumflex artery around the mitral valve ring, both coronary regions are difficult to search by a conventional method. Then coronary aneurysms of these regions were searched using the subcostal approach in this study. First, the sector beam was directed toward the heart on a plane parallel to a line between the patient's shoulders which allowed simultaneous visualization of four chambers (P1). The area around the mitral valve ring in this plane was examined for coronary aneurysms of the peripheral left circumflex artery. Secondary, the beam section was positioned parallel to the line cutting both the long axes of the sternum and spinal column which allowed visualization of the right ventricular outflow tract, pulmonary valves, interventricular septum, mitral valves and left atrium (P2). Thirdly, the sector plane was angled to the left (P3), and still more to the left (P4) until the left atrium just disappeared. By scanning from P2 to P4, the area around the mitral valve ring was examined for coronary aneurysms of the peripheral left circumflex artery. By scanning from P4 to the cardiac apex (P5), the anterior interventricular sulcus was searched for coronary aneurysms of the peripheral left anterior descending artery. Of 143 patients with Kawasaki disease, aged two months to 8 years, 7 peripheral left coronary aneurysms were visualized in five patients. These were three aneurysms in the left circumflex artery at the origin of the obtuse marginal artery, two aneurysms in segment 13, and two aneurysms in the left anterior descending artery at the origin of the second diagonal branch. These echocardiographic features coincided well in size, shape and anatomic location with angiographic appearances. In one patient whose echocardiogram in sector P2 showed a small echo-free space (2 X 2 mm) at the area around the mitral valve ring, the angiographic study showed the intact left circumflex artery, suggesting that there was a limitation to distinguish a very small coronary aneurysm from a normal one. There was no false negative diagnosis. These results showed that this new echocardiographic technique is useful for detecting peripheral left coronary aneurysms in patients with Kawasaki disease.