Shigeo Hasegawa

Plasma endothelin-1 and thrombomodulin levels in coronary sinus during right atrial pacing and percutaneous transluminal coronary angioplasty

Increases in the levels of plasma endothelins (ETs) have been reported after percutaneous transluminal coronary angioplasty (PTCA). To examine the mechanism of this increase, we measured plasma endothelin-1 (ET-1) and thrombomodulin (TM) levels in both the Valsalva sinus (VAL) and the great cardiac vein (GCV) together with oxygen saturation of the GCV (Sat.GCVO2) during right atrial pacing and PTCA. Thirty patients with stenoses in the left anterior descending coronary arteries were enrolled. A fiberoptic pulmonary artery catheter was placed in GCV for monitoring Sat.GCVO2, and blood sampling was repeated before and after each procedure. ET-1 did not increase during pacing, but after PTCA it significantly increased from basal levels to 24.4+/- 8.3 pg/ml in GCV (P<0.01) and 19.3 +/-7.4 in VAL (P<0.05). Basal TM levels in GCV and VAL were significantly higher in diabetic than in non-diabetic patients, but TM did not change during pacing and PTCA. Sat.GCVO2 significantly decreased from the basal level during pacing and PTCA. We speculate that direct endothelial cell damage is more responsible for the increase of ET-1 during PTCA than myocardial ischemia. Our data indicate that ET-1 may be a useful marker for acute endothelial damage, while TM reflects only chronic and general damage of endothelial cells.

Case report of a heart transplantation in a 16-year-old male

We examined ultrastructural changes and did immunohistochemical studies of atrial natriuretic peptide (ANP) in biopsied samples obtained from the heart of a 16-year-old Japanese boy with dilated cardiomyopathy and from the transplanted donor heart. In the right ventricle of the diseased heart, a small number of atrial granules containing ANP were found in the perinuclear area of the cardiomyocytes and near areas lacking some myofibrils. Although no evidence of rejection was seen in the right ventricle of the transplanted donor heart under the light microscope, electron microscopy revealed moderate degeneration of cardiomyocytes and injuries to capillary endothelial cells. We did not find atrial granules, although the serum ANP level was elevated. These data suggest that the ultrastructural changes in the transplanted heart were related to a mild rejection, the effects of cyclosporin, or the effects of a domino heart transplantation from a patient with cystic fibrosis. Because of the absence of atrial granules in the right venticle, it is postulated that the high serum ANP level may be attributed to merely an increased secretion of ANP from atrial granules in the atria, without secretion of ANP in the ventricles.