Right Ventricular Free Wall Isolation: Effects on Regional Myocardial Blood Flow

We measured and calculated their product, regional myocardial oxygen delivery, in unanesthetized, previously instrumented fetal, newborn, and adult sheep. In the fetus, blood flow and oxygen delivery were greater to the right ventricular free wall than to the left ventricular free wall. In the left ventricular free wall oxygen delivery increased significantly after birth and later decreased to a level in the adult that was similar to that of the fetus. There was a progressive decrease in oxygen delivery to the right ventricular free wall during the developmental period that we studied. Although the inner-to-outer blood flow ratio was significantly lower for the left and right ventricular free walls of the fetuses as compared with the newborns and adults, the ratio was greater than one in all three groups for both of the ventricular free walls. These data demonstrate that the changes that occur in the circulation after birth are associated with significant alterations in right and left ventricular myocardial blood flow and oxygen delivery, which most likely reflect changes in regional myocardial metabolic demands. In addition, there are further significant changes in regional myocardial blood flow during the transition from the newborn to adult hemodynamics.

Download Full-text

Homogeneous distribution and pressure dependent reduction of coronary blood flow in right ventricular free wall during coronary hypoperfusion in anaesthetised open chest dogs

Cardiovascular Research ◽

10.1093/cvr/23.1.31 ◽

1989 ◽

Vol 23 (1) ◽

pp. 31-39 ◽

Cited By ~ 3

Author(s):

H. TOMOIKE ◽

Y. URABE ◽

K. OHZONO ◽

S. KOYANAGI ◽

M. NAKAMURA

Keyword(s):

Blood Flow ◽

Right Ventricular ◽

Coronary Blood Flow ◽

Ventricular Free Wall ◽

Homogeneous Distribution ◽

Free Wall ◽

Right Ventricular Free Wall ◽

Open Chest

Download Full-text

Regional myocardial blood flow during pericardial tamponade

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y84-086 ◽

1984 ◽

Vol 62 (5) ◽

pp. 539-543 ◽

Cited By ~ 6

Author(s):

Gerald C. Taichman ◽

Paul Byrne ◽

George V. Forester ◽

Wilbert J. Keon

Keyword(s):

Blood Flow ◽

Myocardial Blood Flow ◽

Right Ventricular ◽

Ventricular Volume ◽

Pericardial Tamponade ◽

Left Ventricular ◽

Regional Myocardial Blood Flow ◽

Pericardial Cavity ◽

Blood Flows ◽

Regional Myocardial Blood

The relative changes in myocardial blood flows within different parts of the heart were measured in anaesthetized thoracotomized dogs during and following effusive pericardial tamponade. Blood flows measured in a group of animals bled to the same arterial hypotensive levels served as experimental controls. The results demonstrate that regional myocardial blood flows to all areas were severely reduced during tamponade. Regional differences in the relative responses were evident; right and left atrial flows decreased more than left ventricular or septal flows which in turn decreased more than right ventricular flow. Significant changes in transmural flow distributions were seen as well; on a relative basis, left and right ventricular endocardial flows decreased more than epicardial and the flow within the left side of the septal wall decreased more than the right. Although decreases in aortic pressure and ventricular volumes can account for some of these changes in flow seen in tamponade, alterations in extravascular compression appear to further reduce the myocardial perfusion and may be responsible for the differences in regional responses. In further experiments when the pericardial cavity was drained following 2 h of tamponade, a hyperemic response was seen throughout the heart indicating that the myocardial flow during tamponade may-have been insufficient to meet the cardiac demands. In conclusion tamponade appears to result in a disproportionate decrease in myocardial blood flow to various parts of the heart which cannot be explained on the basis of a decrease in blood pressure or a reduction in ventricular volume.

Download Full-text