Lesson
The most successful treatment for cardiovascular disease is prevention. A healthy lifestyle consisting of a balanced diet and exercise promote a life free from heart disease when practiced early on. However, heredity can play a role in the development of cardiovascular disease and a person may still be diagnosed regardless how health conscious they are.
Thankfully, there are a number of treatment options available that have proven be successful.
By Pass Surgery
Before we begin our examination of by pass surgery I would invite you to visit the following link Click Here.
An animation of bypass surgery can be viewed here.
Often heart attacks occur because of a blockage in the artery that supplies the heart with blood. The heart is deprived of the oxygen that it needs to functions properly and the tissue begins to die. A coronary artery bypass graft (CABG) is used to correct this problem. In this procedure, a healthy artery or vein taken, or grafted, from the leg, arm or chest is used to create a bypass or an alternate route that will carry oxygenated blood around the blockage and to the heart. The internal mammary artery (IMA) located in the chest is used often because of its ability to remain open for a long period of time. Additionally, the saphenous vein in the leg and the radial artery in the arm are also used. Surgeons can select a number of sites to place the graft. For example:
- Left main (LM) coronary artery, which supplies the left ventricle of the heart (the main pumping chamber)
- Left anterior descending (LAD) artery, a branch off the LM artery
- Obtuse marginal branch (OMB) of the circumflex (CIRC) artery that also branches off the LM coronary artery
- CIRC artery
- Right coronary artery (RCA)
- Posterior descending artery (PDA) of the RCA
During the surgery, a shunt is sometimes used. This tiny device will direct blood flow away from the operation site to allow the surgeon to have a clear field of view, free of blood.
Angioplasty
Healthy arteries are smooth and flexible, allowing blood to flow freely to the heart muscle. When fats and cholesterol accumulate on the inner lining of the artery, the passageway becomes narrow and the flow of blood is impeded. This can result in atherosclerosis and eventually lead to angina (chest pain indicating an onset of a heart attack), heart attacks and strokes. Coronary angioplasty is a procedure that is used to treat this occurrence by opening up the blocked vessel.
Plaque Buildup in a Blood Vessel
The procedure widens the narrowing artery with an artery balloon that is fed through a blood vessel in your groin. This non-invasive procedure, which may take from 30 minutes to 2 hours to complete, does not require major surgery and the body is not cut open. Instead, a short tube called a sheath is placed in the leg and a guide catheter is inserted. Using X rays and a dye, the physician is able to determine if the target area in the coronary artery has been reached. A tiny, deflated balloon inside a another catheter is fed through the guide catheter. The coronary artery balloon travels to the coronary artery where it becomes inflated, dilating the vessel by stretching the artery walls. Chest pain is common during this part of the procedure because blood flow is temporary cut off.
Attached to the balloon catheter is tiny mesh like device called a stent. As the balloon inflates, the stent expands and locks onto the artery wall. The purpose of the stent is to keep the artery open after the angioplasty has been performed.
To complete the procedure, the balloon catheter is removed. Before the guide catheter is removed, the physician takes more X-ray images to ensure that blood flow is restored.
Although stents do not completely prevent further blockages from occurring, it has been proven that the use of a stent reduces the likelihood of renarrowing of the arteries by 50 percent. Research is continually being carried out to refine this procedure even more.
To see an animation of the procedure Click Here
Use of a Stent
Clot Busting Drugs
Heart attacks and strokes can also occur as a result of a clot formation in the artery that supplies the heart with oxygenated blood. There are medications available that prevent the formation of the clot and others that dissolve the clot once it has been formed. The thrombolytic, or clot busting, medications must be given immediately when symptoms appear to prevent a heart attack. The sooner the drug is administered, the greater the chance of recovery. The drug is given intravenously, via a thin catheter leading directly to the site of the blockage. Because thrombolytic medications are not anticoagulants, the risk of bleeding is increased. An anticoagulant prevents bleeding by clotting the blood, whereas thrombolytic drugs are responsible for dissolving clots.
Although clot busters can save the life of a person having a heart attack or stroke, there is also a higher risk of bleeding associated with clot busters than with anticoagulants. Alternatively, clot busters may be administered directly to the site of the clot via a thin tube (catheter), allowing for a greater dose of the drug with fewer potential side effects. Additional investigation into this alternative form of administering clot busters is necessary.
Activity
- Read Pages 326 - 328 in McGraw Hill Ryerson
- Answer Questions 6 & 7 on Page 328 and Question 30 on Page 331 of McGraw Hill Ryerson. Submit your answers to your instructor.
- Answer the following, "Why is ASA sometimes prescribed for patients with a history of Cornary Disease?" , Submit your response to your instructor.
Test Yourself
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