Coronary bypass surgery depends on the degree of narrowing of the coronary arteries as indicated by a coronary angiogram and the specific circumstances of the patient. The principle of cardiac bypass is to create a passageway between the narrowed or blocked ends of a heart vessel so that blood can pass through the narrowed or blocked heart vessel. Heart bypass surgery, also known as coronary artery bypass grafting, is an effective treatment for blocked blood vessels in the heart, known as coronary artery disease. The number and exact location of the bypass grafts will be determined by the extent and location of the narrowed coronary arteries on the patient’s angiogram. If heart bypass grafting is required, it is advisable to seek prompt medical attention.