Comparative analysis of cardiac cycle length during exercise in healthy people and cardiac patients

Arterio-venous oxygen difference is very high at rest (70-80%) and is the main determinant to set an increase in coronary blood fiow as the major mechanism to meet myocardial oxygen requirements during exercise. Cor­ onary blood fiow is not evenly distributed throughout the myocardium during cardiac cycle: it is higher in the subepicardium during systole and higher in the suben­ docardium during diastoJet and mainly depends on two factors: heart rate (HR) and blood pressure.