Changes in preload via blood withdrawal and infusion in acute ischemic canine hearts showed that stroke volume is affected by end-diastolic length, ejection shortening, and isovolumetric bulging.
Does changing preload via blood withdrawal and infusion affect regional myocardial motion in acute ischaemic canine hearts?
In acute ischemia, changes in preload inversely affect isovolumetric shortening in non-ischemic versus ischemic regions, influencing stroke volume.
The effect of changes in preload on regional myocardial motion in acute ischaemia was examined by miniature ultrasonic gauges after left anterior descending coronary artery occlusion in eight open chest dogs with the pericardium preserved. Left ventricular end-diastolic pressure was varied by blood withdrawal and infusion. When preload changed, isovolumetric shortening in the non-ischaemic region was inversely related to that in the ischaemic region. When preload decreased, stroke volume decreased and was accompanied by a decrease in end-diastolic length and ejection shortening in the non-ischaemic region together with an increase in isovolumetric bulging in the ischaemic region. When preload increased, these variables changed in opposite directions. These results indicate that in acute ischaemia: (1) changes in isovolumetric shortening in the non-ischaemic and ischaemic regions were related with each other when the level of volume expansion varied, and suggest that; (2) stroke volume is affected by end-diastolic length, ejection shortening in the non-ischaemic region and isovolumetric bulging in the ischemic region.
Ishikawa et al. (Fri,) conducted a other in acute ischaemia (n=8). blood withdrawal and infusion was evaluated on regional myocardial motion. Changes in preload via blood withdrawal and infusion in acute ischemic canine hearts showed that stroke volume is affected by end-diastolic length, ejection shortening, and isovolumetric bulging.