Coronary Artery Disease

coronary artery disease

  • Is characterized by the accumulation of plaque within coronary arteries, which progressively enlarge, thicken and calcify. This causes critical narrowing of the coronary artery lumen (75% occlusion), resulting in a decrease in coronary blood flow and an inadequate supply of oxygen to the heart muscle.
  • Ischemia may be silent (asymptomatic but evidenced by ST depression of 1 mm or more on electrocardiogram (ECG) or may be manifested by angina pectoris (chest pain).
  • Risk factor for Coronary Artery Disease include dyslipidemia, smoking, hypertension, male gender (women are protected until menopause), aging, non-white race, family history, obesity, sedimentary lifestyle, diabetes mellitus, metabolic syndrome, elevated homocysteine, and stress.
  • Acute coronary syndrome is a complication of CAD due to lack of oxygen to the myocardium. Mnaifestations include unstable angina, non ST-segment elevation infarction, and ST-segment elevation infarction.
  • Other causes of angina include coronary artery spasm, aortic stenosis, cardiomyopathy, severe anemia, and thyrotoxicosis.

Assessment:

chest pain Chest pain is provoked by exertion or stress and is relieved by nitroglycerin and rest.

  1. Character. Substernal chest pain, pressure, heaviness, or discomfort. Other sensations include a squeezing, aching, burning, choking, strangling, or cramping pain.
  2. Severity. Pain maybe mild or severe and typically present with a gradual buildup of discomfort and subsequent gradual fading away.
  3. Location. Behind middle or upper third of sternum; the patient will generally will make a fist over the site of pain (positive Levine sign; indicates diffuse deep visceral pain), rather than point to it with fingers.
  4. Radiation. Usually radiates to neck, jaw, shoulders, arms, hands, and posterior intrascapular area. Pain occurs more commonly on the left side than the right; may produce numbness or weakness in arms, wrist, or hands.
  5. Duration. Usually last 2 to 10 minutes after stopping activity; nitroglycerin relieves pain within 1 minute.
  6. Precipitating factors. Physical activity, exposure to hot or cold weather, eating a heavy meal, and sexual intercourse increase the workload of the heart and, therefore, increase oxygen demand.
  7. Associated manifestation. Diaphoresis, nausea, indigestion, dyspnea, tachycardia, and increase in blood pressure.
  8. Signs of unstable angina:
  • A change in frequency, duration, and intensity of stable angina symptoms.
  • Angina pain last longer than 10 minutes, is unrelieved by rest or sublingual nitroglycerin, and mimics signs and symptoms of impending myocardial infarction.

Diagnostic Evaluation:

  1. Resting ECG may show left ventricular hypertrophy, ST-T changes, arrhythmias, and possible Q waves.
  2. Exercise stress testing with or without perfusion studies shows ischemia.
  3. Cardiac catheterization shows blocked vessels.
  4. Position emission tomography may show small perfusion defects.
  5. Radionuclide ventriculography shows wall motion abnormalities and ejection fraction.
  6. Fasting blood levels of cholesterol, low density lipoprotein, high density lipoprotein, lipoprotein A, homocysteine, and triglycerides may be abnormal.
  7. Coagulation studies, hemoglobin level, fasting blood sugar as baseline studies.

Pharmacologic Interventions:

  1. Antianginal medications (nitrates, beta-adrenergic blockers, calcium channel blockers, and angiotensin converting enzyme inhibitors) to promote a favorable balance of oxygen supply and demand.
  2. Antilipid medications to decrease blood cholesterol and tricglyceride levels in patients with elevated levels.
  3. Antiplatelet agents to inhibit thrombus formation.
  4. Folic acid and B complex vitamins to reduce homocysteine levels.

Surgical Interventions:

  1. Percutaneous transluminal coronary angioplasty or intracoronary atherectomy, or placement of intracoronarystent.
  2. Coronary artery bypass grafting.
  3. Transmyocardial revascularization.

Nursing Interventions:

  1. Monitor blood pressure, apical heart rate, and respirations every 5 minutes during an anginal attack.
  2. Maintain continuous ECG monitoring or obtain a 12-lead ECG, as directed, monitor for arrhythmias and ST elevation.
  3. Place patient in comfortable position and administer oxygen, if prescribed, to enhance myocardial oxygen supply.
  4. Identify specific activities patient may engage in that are below the level at which anginal pain occurs.
  5. Reinforce the importance of notifying nursing staff whenever angina pain is experienced.
  6. Encourage supine position for dizziness caused by antianginals.
  7. Be alert to adverse reaction related to abrupt discontinuation of beta-adrenergic blocker and calcium channel blocker therapy. These drug must be tapered to prevent a “rebound phenomenon”; tachycardia, increase in chest pain, and hypertension.
  8. Explain to the patient the importance of anxiety reduction to assist to control angina.
  9. Teach the patient relaxation techniques.
  10. Review specific factors that affect CAD development and progression; highlight those risk factors that can be modified and controlled to reduce the risk.

Angioplasty Procedure Video

Daisy Jane Antipuesto RN MN

Currently a Nursing Local Board Examination Reviewer. Subjects handled are Pediatric, Obstetric and Psychiatric Nursing. Previous work experiences include: Clinical instructor/lecturer, clinical coordinator (Level II), caregiver instructor/lecturer, NC2 examination reviewer and staff/clinic nurse. Areas of specialization: Emergency room, Orthopedic Ward and Delivery Room. Also an IELTS passer.

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