The role of the Gregg phenomenon in cardiac performance.

Abstract

The Gregg phenomenon has not, yet, a full and complete explanation. We are allowed to consider it a "garden house"-like effect. Positive inotropic factors are released as a consequence of "shear stress" phenomenon following an increased coronarian flow. In our study, it is more probably a "garden house"-like effect that causes a sarcomere stretch. This could explain the increased left ventricle performance found, in some circumstances, in our study. We used the data obtained by coronarography in 22 patients carrying various degrees of coronarian obstruction and we assessed the left ventricle performance during the repeated injection of contrast medium, that increases the pressure in the coronarian bed. The results obtained support the theory regarding the Gregg effect but do not allow us to consider this effect as a fundamental determinant of the cardiac performance.