Coronary Artery Disease PDF

# Coronary Artery Disease Coronary artery disease (CAD) is a narrowing or blockage of coronary arteries, usually due to plaque buildup. Coronary arteries supply oxygen-rich blood to the heart. Plaque limits how much blood can reach the heart. ## 1. Coronary Atherosclerosis Atherosclerosis is the...

# Coronary Artery Disease Coronary artery disease (CAD) is a narrowing or blockage of coronary arteries, usually due to plaque buildup. Coronary arteries supply oxygen-rich blood to the heart. Plaque limits how much blood can reach the heart. ## 1. Coronary Atherosclerosis Atherosclerosis is the buildup of fats, cholesterol, and other substances on artery walls. This buildup is called plaque. The plaque can cause arteries to narrow, blocking blood flow. The plaque can lead to a blood clot. ### Causes The exact cause for atherosclerosis is unknown. It may start with damage or injury to the inner layer of an artery. Damage may be caused by: * High triglycerides, a type of fat (lipid) in the blood * High blood pressure * Smoking * Insulin resistance * High cholesterol * Diabetes * Obesity * Inflammation from an unknown cause or from diseases such as arthritis. ### Pathophysiology 1. Low-density lipoprotein molecules (LDL) become oxidized by oxygen free. When oxidized LDL comes in contact with an artery wall, a series of reactions occur to repair the damage to the artery wall caused by oxidized LDL. 2. The body's immune system responds to the damage to the artery wall caused by oxidized LDL, by sending specialized white blood cells (macrophages and T-lymphocytes) to absorb the oxidized-LDL, forming specialized foam cells. ## Lipid Profile * **Lipoproteins** are referred to as low-density lipoproteins (LDL) and high-density lipoproteins (HDL). * **LDL** (normal level, less than 130 mg/dL) are the primary transporters of cholesterol and triglycerides into the cell. One harmful effect of LDL is the deposition of these substances in the walls of arterial vessels. * **HDL** (normal range in men, 35 to 65 mg/dL; in women, 35 to 85 mg/dL) have a protective action. They transport cholesterol away from the tissue and cells of the arterial wall to the liver for excretion. * **Cholesterol** (normal level, less than 200 mg/dL, High: = 240 mg/dL) * **Triglycerides** (normal range, 40 to 150 mg/dL) composed of free fatty acids and glycerol, are stored in the tissue and are a source of energy. * These white blood cells are not able to process the oxidized-LDL, and ultimately grow then rupture. * Eventually, the artery becomes inflamed. * The cholesterol plaque causes the muscle cells to enlarge and form a hard cover over the affected area. This hard cover causes a narrowing of the artery, reduces the blood flow and increases blood pressure. ## Stages of Atherosclerosis | Stage | Description | |---|---| | Healthy artery | Normal artery with no plaque build up| | Plaque forms | Small deposits of plaque begin to form on the artery walls| | Cholesterol deposited | Plaque starts to build up in the artery| | Build-up begins | Plaque continues to build up restricting blood flow| ## Normal Heart and Artery vs. Artery with Plaque Buildup | Normal Heart and Artery | Artery with Plaque Buildup | |---|---| | * Normal artery wall * Red blood cells * Coronary artery * Heart | * Artery wall * Red blood cells * Plaque * Narrowed coronary artery * Heart * Fat | ## Physiologic Factors that Increase Risk ### Modifiable * Having diabetes * Tobacco smoking, increases risk by 200% after several pack years * Having high blood pressure * Elevated serum C-reactive protein concentrations ### Nonmodifiable * Advanced age * Male sex * Having close relatives who have had some complication of atherosclerosis (e.g., coronary heart disease or stroke) * Genetic abnormalities, e.g. familial hypercholesterolemia ### Lesser or Uncertain * Being obese (in particular central obesity (also referred to as abdominal obesity)) * A sedentary lifestyle * High carbohydrate intake * Elevated serum levels of triglycerides * Stress ## Signs and Symptoms Signs and symptoms depend on the degree of narrowing of the arterial lumen, thrombus formation and obstruction of blood flow, as following: 1. Inadequate supply of blood that leads to deprives in oxygen in muscle (ischemia) 2. Angina pectoris, chest pain that is brought about by myocardial ischemia, usually caused by coronary atherosclerosis 3. If blood supply decreases is great and longer, myocardial infarction produce 4. Damaged myocardium replaced by scar tissue causing various degrees of myocardium dysfunction 5. Inadequate cardiac output and heart failure occur ## Treatment * Non-pharmacological means are usually the first method of treatment, such as cessation of smoking and regular exercise. If these methods do not work, medicines are usually the next step. * **1-Statins:** In general, the group of medications referred to as statins that has been widely prescribed for treating atherosclerosis. Example: lovastatin (20-80mg), simvastatin (zocar 20-80 mg) and fluvastatin (lescol 20-80 mg) * **Its action:** block cholesterol synthesis, lower low density lipoprotein (LDL) and triglyceride levels and increase high density lipoprotein (HDL). * **2-Nicotinic acids.** As niacin (niaspan) it decreases lipoprotein synthesis, lower low-density lipoprotein and triglyceride levels and increase high-density lipoprotein. It is used for minimal elevated cholesterol and low density lipoprotein levels. * **3-Fibric acid or fibrates (atromid).** It is used to lower low triglyceride levels and increase high density lipoprotein. It is indicated for patients with triglyceride levels above 400 mg/dl. * **4-Bil acid resins (cholestyramine)** It binds with cholesterol in the intestine, increasing its breakdown and lower low density lipoprotein, no effect on triglyceride. It is used for patients with triglyceride levels less than 200 mg. ## Prevention 1. **Controlling cholesterol abnormalities** * Four elements of fat metabolism (total cholesterol, low-density lipoprotein, high-density lipoprotein, and triglycerides must be controlled. * Lipids should be checked every 6 weeks until desired levels obtained and then every 4-6 months. * HDL should exceed 40 mg/dl and should be ideally more than 60 mg/dl, HDL is protective for the patient. * Elevated triglyceride more than 200 mg/dl may be genetic and caused by obesity, physical inactivity, high carbohydrate diet, and DM and kidney disease. 2. **Dietary measures** * Vitamin C acts as an antioxidant in vessels and inhibits inflammatory processes. It has therapeutic properties on high blood pressure and arterial stiffness in diabetes. Vitamin C is also a natural regulator of cholesterol and higher doses (over 150 mg/kg daily). * Total fat must be 25-35% of total calorie, CHO must be 50-60%, fiber must be 20-30 g/day, protein must be 15% and cholesterol less than 200mg/day * Dietary fiber helps in lowering cholesterol levels, which can be found in fresh fruits, vegetables, enhance excretion of metabolized cholesterol. 3. **Physical activity** * Combining a healthy diet with regular exercise is the best way of maintaining a healthy weight. Having a healthy weight reduces chances of developing high blood pressure. * Instruct patients to stop any activity if they feel chest pain, unusual shortness of breath, dizziness, or nausea. 4. **Promoting cessation of tobacco use** * Smoking constricts blood vessels, forcing the heart to work even harder to pump blood. * Quitting smoking is one of the best ways to lower risk of coronary artery disease and improve overall health. * A smoking cessation program can help successfully quit smoking — and start experiencing health benefits the same day you quit. 5. **Managing hypertension** * Hypertension is blood pressure measurement exceeding 140/90 mm/hg, long-standing elevated blood pressure results in stiffness of the vessel walls leading to vessel injury and inflammatory response within intimae. * It also increases the work of the left ventricle which pumps harder to eject blood into arteries. Increase workload causes the heart to enlarge and thicken which lead to cardiac failure. ## Angina Pectoris ### Definition * Severe chest pain due to ischemia (a lack of blood and oxygen supply) of the heart muscle, due to obstruction of the coronary arteries. ### Subtypes of Angina * **1-Stable angina:** This refers to angina related to myocardial ischemia. Typical presentations of stable angina are that of chest discomfort and develops when the heart works harder in the case of exercise with minimal symptoms at rest. Lasts a short time, perhaps five minutes or less. * **2-Unstable angina:** Is defined as angina pectoris that changes or worsens. It has at least one of these three features: * It occurs at rest (or with minimal exertion). * It is severe. * It occurs with a crescendo pattern (i.e., distinctly more severe, prolonged, or frequent than previously). * **3-Variant angina:** Occurring at night (unrelated to activity). it is caused by coronary artery spasm with or without atherosclerotic lesions. It may result from hyperactive of sympathetic nervous system responses. * **4-Silent ischemia:** It may occur with either activity or with mental stress. ## Risk Factors of Angina Pain 1. **Physical exertion** which start attack by increase oxygen demand. 2. **Exposure to cold** which cause vasoconstriction and increase blood pressure with increase oxygen demand. 3. **Eating heavy meals** which increase blood flow to the mesenteric area for digestion and decrease blood supply to the heart muscle. 4. **Stress** causing increase blood pressure and increase myocardium workload. 5. **Obesity** raises the risk of angina and heart disease because it's associated with high blood cholesterol levels, high blood pressure. ## Symptoms * **Chest discomfort:** The discomfort is usually described as a pressure, heaviness, tightness, and squeezing, burning, or choking sensation. Anginal pains radiate in the epigastrium (upper central abdomen), back, neck, jaw, or shoulders. This is explained by the concept of referred pain. Typical locations for referred pain are arms (often inner left arm), shoulders, and neck into the jaw. * **Pain** may be accompanied by breathlessness, sweating, and nausea in some cases. It usually lasts for about 3 to 5 minutes. * **Myocardial ischemia** comes about when the myocardium (the heart muscles) receives insufficient blood and oxygen to function normally. * **"Autonomic symptoms" (related to increased activity of the autonomic nervous system)** such as nausea, vomiting, and pallor. * **Weakness, numbness** in the arm, wrist and hands may accompany pain. ## Diagnosis 1. **Electrocardiogram (ECG):** measures the electrical activity in the heart and evaluates heart rhythm. 2. **Exercise ECG test:** May be performed, during which the patient exercises to their maximum ability before fatigue, breathlessness or pain. If characteristic ECG changes are documented. 3. **Coronary angiogram:** Is a procedure that uses X-ray imaging to see the heart's blood vessels. The test is generally done to see if there's a restriction in blood flow going to the heart. 4. **Echocardiography:** Is a non-invasive procedure that uses ultrasound to evaluate the cardiac structure and function. It may be done at rest, during supine exercises. 5. **C-reactive protein** is indicated due to coronary artery disease as a result from inflammation. ## Medical Management Goal of management are to decrease demand of myocardium and increase oxygen supply. It is achieved by pharmacologic therapy. 1. **Pharmacological therapy** includes the following: * **A-Nitroglycerine;** isosorbide dinitrate (isordil), it is given sublingual, by spray or IV for immediate effect or orally. Sublingual nitroglycerine acts within 1-2 minutes, decreases myocardial work and oxygen demand through dilate veins, and dilate artery. It helps increase coronary blood flow by preventing vasospasm. * **B-Beta-adrenergic blocking agents** (inderal): It reduces myocardial oxygen consumption which leads to a decrease in heart rate, decrease blood pressure and reduce myocardial contractility that provide a balance between myocardial needs and supply of oxygen, this helps in control chest pain. * **C- Calcium channel blocking agents:** as (procardial, vascor). It is used to control angina, hypertension by slowing heart rate. It also relaxes blood vessels causing a decrease in blood pressure. It increases myocardial oxygen supply by dilating smooth muscle walls of the coronary arteriole. * **D-Antiplatelet drugs:** Given to prevent platelet aggregation which impedes blood flow. It includes: * **1-Aspirin:** They prevent platelet activation in arteries, preventing development of arterial thrombus. The dose of aspirin is given is 80-325 mg/ day. * **2-Intravenous antiplatelet drugs:** as (reopro) It blocks the final common pathway of platelet activation but the risk of bleeding is greater than with orally administered antiplatelet drugs. * **E-Heparin (anticoagulant drugs):** Prevents formation of new blood clots, reduces occurrence of myocardium infarction, if a patient is hospitalized he is given heparin every 4-6 hours. 2. **Oxygen administration** - Usually initiated at onset of chest pain to increase the amount of oxygen delivered to the myocardium and decrease pain. ## Nursing Process for Angina Pectoris ### Assessment * **Health history** as chest pain, including type, intensity, duration, aggravating factors and relief measures; associated symptoms. * **History of other cardiovascular disorder**, stroke, current medications and treatment, unusual diet, exercise and alcohol intake pattern, smoking history, use of other drugs. * **Physical assessment:** Vital signs and heart sounds, strength and equality of peripheral pulses, skin color and temperature (central and peripheral), physical appearance during pain episode (e.g., shortness of breath, apparent anxiety, color). ### Prevention * Quitting smoking * Monitoring and controlling other health conditions, such as high blood pressure, high cholesterol, and diabetes. * Eating a healthy diet and maintaining a healthy weight. * Increasing physical activity for 150 minutes of moderate activity each week. Plus 10 minutes of strength training twice a week and to stretch three times a week for 5 to 10 minutes each time. * Reducing your stress level. * Limit alcohol consumption to two drinks or fewer a day for men, and one drink a day or less for women. * Get an annual flu shot to avoid heart complications from the virus. ### Nursing Diagnosis and Interventions * **1-Ineffective myocardial tissue perfusion related to decrease blood supply as manifested by chest pain** * **Goal:** Improve tissue perfusion, decrease chest pain. * **Nursing care:** * Nurse should direct the patient to stop all activities and sit or rest in bed in a semi-Fowler position to reduce oxygen requirement. * Nurses assess patients' angina and continuously assess patients. * Measure vital signs and observe signs of respiratory distress. * Keep prescribed nitroglycerine tablets at the patient's side. * Start oxygen to reduce myocardial hypoxia and smoking cessation. * Space activities to allow rest between them, activity increase cardiac work and may precipitate angina. * Teach about prescribed medications to maintain myocardial perfusion and reduce cardiac work. * **2-Anxiety related to fear of death** * **Goal:** Reducing anxiety. * **Nursing care:** * Providing information about illness, treatment, and methods of preventing its progression is very necessary to decrease anxiety. * Various stress reduction methods should be explored with the patient, such as music therapy, relaxation techniques. * Give patients the opportunity to express feelings and ask any questions. * **3-Pain related to decrease oxygen supply to myocardium muscle** * **Goal:** Preventing or reducing pain. * **Nursing care:** The nurse assesses patient pain and if activity increases patient pain, plan activities according to the ability of the patients. * Balance between rest and activity and rest is very important aspect of educational plan for patients and family. * Keep prescribed nitroglycerine tablets at the patient's side so one can be taken at the onset of pain.