| Abstract: | The characteristic narrowing of left main coronary artery (LMCA) was found in 44% of patients (pts) with atrial septal defect and pulmonary hypertension (ASD + PH). The cause of the narrowing is thought to be the compression by pulmonary trunk (PT). Cardiac catheterization and coronary arteriography (CAG) were performed in 38 pts with ASD ranging in age from 15 to 62 years. We defined abnormal narrowing as 50% or more stenosis of AHA classification. Sixteen pts (42%) had PH, and of these pts 7 show the abnormal narrowing of LMCA. (18% of all pts with ASD, 44% of pts with ASD + PH). They had no signs of syphilis or aortitis. Of the pts with PH, those with abnormal LMCA revealed higher pulmonary artery mean pressure than those with normal LMCA (43.6 +/- 17.3 and 27.1 +/- 5.5 mmHg respectively. p less than 0.01). Other parts of coronary arteries are intact in all pts. These findings suggest that the LMCA abnormality relates to PH. In all cases with LMCA abnormality the narrowing revealed some special features indicate the cause of narrowing is compression. First, the most severe part of narrowing was the coronary ostium, and severity reduced gradually as distal LMCA. Second, the narrowing was estimated most severely in the view of LAO 20, but almost normal in the view of RAO 30. This finding suggests the narrowing is ellipsoid. Third, the shape of LMCA changed in the different phase of cardiac cycle. In the systole, the cranial border of LMCA was convex, but in the diastole it was concave. This indicates LMCA was soft and compressed.(ABSTRACT TRUNCATED AT 250 WORDS) |
