Abstract
End-diastoltc dilatation and reduced systolic shortening are the characteristic dimensional changes during myocardial ischaemia. Elevation of systolic aortic blood pressure by 5.3 kPa (40 mm Hg) normalized shortening and reduced myocardial dilatation when the tissue rendered ischaemic by coronary artery occlusion was less than 20% of the left ventricle. However, when the ischaemic lesion was more extensive, an adverse eifect of raising aortic blood pressure was observed.