• Left coronary artery carries about 85 percent of blood supply to myocardium
– Right coronary artery carries the rest
– Pumping action of heart is product of rhythmic,alternate contraction and relaxation of atria and ventricles
– Stroke volume is amount of blood ejected from each ventricle with one contraction
• Depends on preload, afterload, and myocardial contractility
– Cardiac output is amount of blood pumped by each ventricle per minute