Does coronary sinus occlusion affect coronary pressure-flow relations in anesthetized open-chest dogs?
Coronary sinus pressure acts as an extravascular compression rather than a perfusion pressure, directly affecting the zero-flow pressure intercept in the coronary circulation.
Effect of coronary sinus (CS) occlusion on pressure-flow relations was studied at paek reactive hyperemia in anesthetized open-chest dogs during vagal arrest. CS was closed by a specially designed balloon cather.The pressure-flow relations were lineal in both the left anterior descending coronary artery (LAD) and the left circumflex coronary artery (LCX). With CS occlusion, the pressure-flow relations did not change in slope, but shifted to the right in both LAD and LCX. The zero-flow pressure intercept (PF=0) was 22±4mmHg in LAD, and 17±6mmHg in LCX with the CS open. There was no significant difference in The PF=0 between LAD ahd LCX. The PF=0 varied directly with changes in CS pressure caused by CS occlusion. Two Variables fitted closer in LCX than LAD. Even a slight elexation in CSP affected PF=0. Therefore, it is supposed that CSP worke as an extravascular compression rather than as a perfusion pressure.
Osamu Nishiyama (Sun,) studied this question.