ANGINA PECTORIS

• Angina = a sense of suffocation or suffocating pain
• Angina pectoris is a clinical syndrome usually characterized by episodes or Transient paroxysms pain or pressure in the anterior chest.
• The cause is temporary myocardial ischemia usually due to insufficient coronary blood flow.
• The insufficient flow results in a decreased oxygen supply to meet an increased myocardial demand for oxygen in response to physical exertion or emotional stress. In other words, the need for oxygen exceeds the supply. Resulting to myocardial ischemia.
• Angina is usually caused by Atherosclerotic Disease.

Types of Angina

• Stable Angina / Angina Pectoris
  • Occurs when the heart must work harder, usually during physical exertion
  • Doesn't come as a surprise, and episodes of pain tend to be alike
  • Usually lasts a short time (5 minutes or less)
  • Is relieved by rest or medicine
  • May feel like gas or indigestion
  • May feel like chest pain that spreads to the arms, back, or other areas
  • Possible triggers - Emotional stress, Exposure to very hot or cold temperatures, Heavy meals and Smoking
• Unstable Angina
  • also called pre infarction angina or crescendo angina
  • Often occurs while resting, sleeping, or with little physical exertion
  • Comes as a surprise
  • May last longer than stable angina
  • May Rest or medicine do not help to relieve it
  • May get worse over time - symptoms increase in frequency and severity
  • Can lead to a heart attack
• Prinzmetal angina
  • Also known as - Variant angina, Prinzmetal's variant angina and Angina inversa
  • Caused by a spasm in the coronary arteries as a result of:
  • Exposure to cold weather, Stress, Medicines produce vasoconstriction, Smoking and Cocaine use
  • Usually occurs while resting and during the night or early morning hours
  • Are usually severe
  • Can be relieved by taking medication
• Microvascular Angina
  • Due to Spasms within the walls of these very small arterial blood vessels, causes reduced blood flow to the heart muscle leading to a type of chest pain referred to as microvascular angina.
  • Differ from the typical angina that occurs in heart disease
  • May be more severe and last longer than other types of angina pain
  • May occur with shortness of breath, sleep problems, fatigue, and lack of energy
  • Often is first noticed during routine daily activities and times of mental stress
• Silent ischemia: objective evidence of ischemia (such as electrocardiographic changes with a stress test), but patient reports no symptoms

Precipitating Factors (4 E's of ANGINA PECTORIS)

• Excessive physical exertion (heavy exercises) - which can precipitate an attack by increasing myocardial oxygen demand.
• Exposure to cold environment - it cause vasoconstriction and an elevated blood pressure, with increased oxygen demand
• Extreme emotional response (fear, anxiety, excitement) - causing the release of adrenaline and increasing blood pressure, which may accelerate the heart rate and increase the myocardial workload
• Excessive intake of foods - which increases the blood flow to the mesenteric area for digestion, thereby reducing the blood supply available to the heart muscle (In a severely compromised heart, shunting of blood for digestion can be sufficient to induce anginal pain.)

Clinical Manifestations

• Levine's Sign – initial sign that shows the hand clutching the chest
• Chest pain - characterized by sharp stabbing pain located at sub sterna usually radiates from back, shoulder, arms, axilla and jaw muscles, usually relieved by rest or taking nitroglycerine
• Dyspnea
• Tachycardia
• Palpitations
• Diaphoresis

Assessment and Diagnostic Findings

• History Taking and Physical Exam – related to manifestations of ischemia
• ECG - reveals ST segment depression & T-wave inversion
• Stress test /treadmill test – reveal abnormal ECG
• Serum cholesterol and uric acid is increased
• Coronary Angiography

Medical Management

• The objectives of the medical management of angina are to decrease the oxygen demand of the myocardium and to increase the oxygen supply.
• Management includes -
  • Pharmacologic Therapy
    • Nitroglycerin (NGT)
    • Beta-Adrenergic Blocking Agents
    • Calcium Channel Blocker
    • Antiplatelet
    • Anticoagulant
  • Revascularization procedures
    • Percutaneous coronary interventional (PCI)
      • percutaneous transluminal coronary angioplasty [PTCA]
      • Intracoronary stents
      • Atherectomy
    • Coronary arterial bypass grafting (CABG)
    • Percutaneous transluminal myocardial revascularization (PTMR)

Pharmacologic Therapy

NITROGLYCERIN (NGT)

• Actions - Vasodilator - dilate veins more than arteries when given in small doses will act as venodilator, decreases cardiac preload but in large doses will act as vasodilator or dilate arteries against which the heart must pump thereby decreasing afterload resulting reduce myocardial oxygen consumption, which decreases ischemia and relieves pain.
• Route - Sublingual, Oral, Intravenous, Topical, Transdermal
• Dose
  • First dose of NTG (sublingual) 3 – 5 minutes
  • Second dose of NTG if pain persist after giving first dose with interval of 3 - 5 minutes
  • Third and last dose of NTG if pain still persists at 3 – 5 minutes interval
  • if pain persists after taking three sublingual tablets at 5-minute intervals, emergency medical services should be called.
• Nursing care when giving NTG
  • Keep the drug in a dry place, avoid moisture and exposure to sunlight as it may inactivate the drug
  • Monitor side effects – like Orthostatic hypotension, Transient headache and dizziness
  • Instruct the client to rise slowly from sitting position
  • Assist or supervise in ambulation
  • Observe BP for hypotension. usually It is not given if the systolic BP is < 90 mm Hg.
• When giving nitrol or transdermal patch
  • Avoid placing near hairy areas as it may decrease drug absorption
  • Avoid rotating transdermal patches as it may decrease drug absorption
  • Avoid placing near microwave ovens or during defibrillation as it may lead to burns (most important thing to remember)

β - ADRENERGIC BLOCKING AGENTS

• Propranolol (Inderal); Metoprolol (Toprol); Atenolol (Tenormin)
• Action - Beta-Adrenergic Blocking Agents block the beta-adrenergic sympathetic stimulation (block the release of Catetacolemines, Epinephrine and Norepinephrine ) Resulting decrease the heart rate and cardiac output and BP Thus reduced myocardial contractility (force of contraction) that establishes a more favorable balance between myocardial oxygen needs (demands) and the amount of oxygen available (supply). Reduce Myocardial Oxygen Consumption
• Cardiac side effects and possible contraindications
  • Hypotension
  • Bradycardia
  • Bronchospasm - Not given to COPD cases
  • Advanced Atrioventricular Block,
  • Decompensated Heart Failure
• Nursing care when giving β-blocker
  • Monitor vitals signs and the ECG
  • Hold the medication if the pulse or BP is not within the prescribed parameters.
  • Should not be stopped abruptly.
  • Patients with diabetes who take beta-blockers are instructed to assess their blood glucose levels more often and to observe for signs and symptoms of hypoglycemia.
  • Instruct the client to change positions slowly to prevent orthostatic hypotension.
  • Instruct the client to avoid over-the-counter cold medications and nasal decongestants.

CALCIUM CHANNEL BLOCKER

• Nifedipine; Diltiazem; Amlodipine
• Action - Ca-channel blockers decrease cardiac contractility (negative inotropic effect by relaxing smooth muscle) and the workload of the heart, thus decreasing the need for O₂. Calcium channel blockers promote vasodilation of the coronary and peripheral vessels. Reduce Myocardial Oxygen Consumption
• Side effects
  • Bradycardia
  • Hypotension
  • Headache
  • Constipation
  • Changes in liver and kidney function
• Nursing care when giving
  • Monitor vital signs.
  • Monitor for signs of heart failure.
  • Monitor liver enzyme levels.
  • Instruct the client not to discontinue the medication.
  • Instruct the client not to crush or chew sustained-released tablets.

ANTIPLATELET

• Aspirin: It prevents platelet activation and reduces the incidence of MI and death in patients with CAD.
• Dose : 160 – 325 mg should be given to the patient with angina as soon as the diagnosis is made, and then continued with 81 to 325 mg daily.
• Clopidogrel (Plavix): given to patients who are allergic to aspirin or given in addition to aspirin in patients at high risk for MI.
• They also cause gastrointestinal upset, including nausea, vomiting, and diarrhea.

ANTICOAGULANT

• Heparin
• Heparin prevents the formation of new blood clots.
• The amount of heparin administered is based on the results of (aPTT).
• Heparin therapy is usually considered therapeutic when the aPTT is 1.5 to 2 times the normal aPTT value.
• The patient is monitored for signs and symptoms of external and internal bleeding, such as: Low blood pressure, An increased heart rate, Decrease in serum hemoglobin and hematocrit values etc.

Revascularization procedures

Percutaneous Transluminal Coronary Angioplasty (PTCA)

• It is an invasive, nonsurgical technique in which the arteries are dilated with a balloon catheter to open the vessel lumen and improve arterial blood flow.

Coronary artery stents (Intracoronary stents)

• Coronary artery stents are used in conjunction with PTCA to provide a supportive scaffold to eliminate the risk of acute coronary vessel closure and to improve long-term patency of the vessel.

Atherectomy

• Atherectomy removes plaque from a coronary artery by the use of a cutting chamber on the inserted catheter or a rotating blade that pulverizes the plaque.

Coronary arterial bypass grafting (CABG) - Traditional

• CABG is invasive, surgical technique in which a healthy artery or vein from the body is connected, or grafted, to the blocked coronary artery. The grafted artery or vein bypasses the blocked portion of the coronary artery. This creates a new path for oxygen-rich blood to flow to the heart muscle.

Percutaneous Transmyocardial Revascularization (PTMR)

• PTMR is a cardiac catheterization based minimally invasive procedure for treating CAD. After the area is numbed with anesthesia, the catheter is inserted in an artery via the leg that leads to the heart. A laser is then fed through the catheter and used to create tiny holes in the heart muscle. These holes become channels for blood to flow to oxygen-starved areas of the heart. Researchers believe that the procedure may cause new vessels to form, reducing the pain of angina. PTMR is currently being used on patients who have not responded to other treatments such as medicines, angioplasty, or coronary artery bypass surgery.

Nursing care

• Enforce complete bed rest
• Administer medications as ordered
• Administer oxygen inhalation
• Place client on semi fowler's position
• Monitor strictly vital signs, intake and output and ECG tracing
• Provide decrease saturated fats sodium and caffeine
• Provide client health teachings and discharge planning
• Avoidance of 4 E's
• Prevent complication (myocardial infarction)
• Instruct client to take medication before indulging into physical exertion to achieve the maximum therapeutic effect of drug
• The importance of follow up care