Autoregulation by the right coronary artery in dogs with open chests; comparison with the left coronary artery |
| |
Authors: | Hideki Tani Daiji Saito Shozo Kusachi Takaaki Nakatsu Kazuyoshi Hina Masayuki Ueeda Hirofumi Watanabe Shoichi Haraoka Takao Tsuji |
| |
Institution: | (1) The First Department of Internal Medicine, Okayama University Medical School, Okayama, Japan;(2) Department of Cardiology, Kawatetsu Mizushima Hospital, 2-6-11, Tsurunoura, 712 Kurashiki, Japan |
| |
Abstract: | Experiments were conducted to study autoregulatory responses of the right and left coronary arteries in dogs with open chests. The right and left circumflex coronary artery were cannulated and perfused with blood from the femoral artery via a pressurized reservoir. The perfusion pressure was varied in steps over a wide range and coronary blood flow rates were measured. Both the right and left coronary arteries exhibited autoregulation but the pressure at the lower end of the autoregulatory range was lower in the right (39.8±9.1 mm Hg) than in the left circumflex coronary artery (57.6±14.5 mm Hg). The slope of the pressure-flow relationship in the autoregulatory range was less steep in the right than the left circumflex coronary artery. The closed-loop gain when the perfusion pressure was less than 100 mm Hg was greater in the right than in the left circumflex coronary artery. Increases in the right ventricular afterload produced by pulmonary artery constriction decreased the closed-loop gain, shifted the autoregulatory range upward and to the right, and made the slope steeper. These results indicate that more effective autoregulation is carried out by the right than the left circumflex coronary artery. |
| |
Keywords: | Autoregulation Right coronary artery Pressure-flow relationship Ventricular works |
本文献已被 SpringerLink 等数据库收录! |