an area of high-density echo suggesting calcification. As a guidewire would not cross the stenosis distal to an old aneurysm at segment 2, we could only see the proximal portion of the new aneurysm at segment 2. There was also partial thickening of the intima-media complex in the vascular wall with a small area of calcification (Fig. 1, left, arrow). Electron beam tomography confirmed that the arterial wall of the new aneurysms in segments 2 and 6 was partially calcified (Fig. 2, right and middle, arrow). The old aneurysm at segment 2 on the first angiogram had a thick calcified arterial wall. The arterial wall of coronary aneurysms that develop during the late follow-up after Kawasaki disease in previously apparent normal coronary arterial segments manifests sclerotic changes such as thickening of the intima-media complex and calcification. Hideshi Tomita, MD Department of Pediatrics Sapporo Medical University School of Medicine Sapporo, Japan REFERENCE 1. Tomita H, Fuse S, Chiba S. Delayed appearance of coronary aneurysms in Kawasaki disease. Heart 1998;80:425. Extreme Left Atrial Enlargement Causing Upward Displacement and Compression of the Right Pulmonary Artery TO THE EDITOR: Left atrial enlargement can produce a variety of compression effects on adjacent structures. These in- clude hoarseness of voice secondary to left recurrent laryngeal nerve palsy [1], dysphagia due to eso- phageal compression [2,3], atelectasis of the lung due to compression of the left main bronchus and pulmonary parenchyma [4], displacement of the descending thoracic aorta to the left [5], outward displacement of the right descending pulmonary artery [4], and erosion of the spine [6]. We report a case of extreme left atrial enlargement producing upward displacement and com- pression of the right pulmonary artery sufficient to produce a pressure gradient recorded by catheter pull- back. A 13-year-old boy presented with severe mitral regurgi- tation and a large perimembranous ventricular septal defect. Chest X-ray showed cardiomegaly with a car- diothoracic ratio of 17/24 cm (70%), left atrial and left ventricular enlargement, and increased lung vas- cularity. EKG showed sinus rhythm, left atrial enlarge- ment, and left ventricular hypertrophy. The left atrial size by parasternal long axis M-mode echocardi- ography was 7.7 cm. Cardiac catheterization revealed a significant left-to-right shunt at the ventricular level (22% step-up; Qp/Qs, 4:1). End-hole catheter pullback from the right pulmonary artery (RPA) to main pul- monary artery (MPA) showed a systolic pressure gradient of 20 mm Hg; systolic/diastolic (mean) pressures, res- pectively, were RPA 25/12 (16) mm Hg and MPA 45/14 (24) mm Hg. Care was taken to ensure that the tip of the catheter in the right pulmonary artery was not wedged distally, and that the pressure tracing was arterial in character. There was no systolic pressure gradient on catheter pullback from the main pulmonary artery to the right ventricle. Pulmonary angiogram in anteroposterior projection (Fig. 1) showed the right pulmonary artery to be displaced upward and narrowed Fig. 1. Pulmonary angiogram in anteroposterior projection showing upward displacement and compression of the right pulmonary artery by an enlarged left atrium. Letters to the Editor 115