Myocardial blood flow in aortic regurgitation: computer-based predictions from wall stress compared with fluorescent microsphere measurements

In severe, chronic aortic regulation (AR) in man, systolic pressure time interval and diastolic pressure time interval measurements suggest an abnormal load-to-endocardial blood flow relationship. To better define this relationship, the authors extended their previously reported model for determining myocardial wall stress in include radial stress from endocardial (ENDO) to epicardium (EPI), a factor believed to influence distribution of coronary blood flow. Estimates of radial, circumferential and meridional stresses were compared with axial and transmyocardial blood flow measured from the base to apex and ENDO to EPI in normal rabbits and rabbits with severe, chronic AR. The authors´ results suggest that blood flow is uniform from base to apex but not from ENDO to EPI near the apex where radial wall stress may influence blood flow