Coronary Artery Disease and Acute Myocardial Infarction

1
Coronary Artery Disease and Acute Myocardial
Infarction

• NPN 200
• Fall 2006

2
Coronary Artery Disease

• Atherosclerosis
• Define thickness and hardening of the arteries
  caused by deposits of fat and fibrin which
  harden.
• Leads to decreased lumen and decreased blood flow
  and ischemia and death of the tissue
• Arteriosclerosis
• Define loss of elasticity and abnormal
  thickening or hardening of the walls of the
  arteries which can be due to accumulation of
  lipids, cholesterol, calcium or thrombus.
• May also lead to occlusion of the lumen of the
  vessel, usually at the bifurcation of the vessels
• May develop collateral circulation if develops
  slowly

3
Signs and Symptoms

• Usually none until 60
• LAD most effected
• Pain usual symptom but may experience dyspnea
• May have irregular heart rate
• N/V may also accompany the other symptoms
• Called angina
• Unstable persistent, even at rest
• Prinzmetal's variant, and may occur without
  atherosclerosis

4
Medical Treatment

• Decrease risk factors
• Diet
• Control cholesterol/triglycerides
• Exercise
• Smoking
• Hypertension
• Drugs
• Calcium channel blockers
• Nitroglycerin
• Low dose ASA
• Surgery

5
Myocardial Infarction

• Myocardial infarction is the necrosis of an area
  of cardiac tissue as a result of obstruction of
  blood flow through a coronary artery or one of
  its branches
• The myocardial tissue dies as a result of the
  occlusion
• The size and location of the necrosed area
  affects the hearts ability to squeeze
• Death occurs from this cardiac damage or
  complications R/T to the MI
• ½ of deaths occur within 1 hour after the onset
  of symptoms

6
Complications of an MI

• Cardiogenic shock
• Arrhythmias
• CHF
• Ventricular rupture or aneurysm
• Pericarditis
• Pulmonary embolism
• Post-myocardial infarction

7
Risk Factors

• Smoking
• Family history
• Hypertension
• Elevated triglycerides and cholesterol levels
• Obesity
• Sedentary lifestyle
• Aging
• Stress
• Men more than women (but women are increasing)
• Diabetes mellitus

8
Causes

• Arthrosclerosis (90)
• Constriction or spasm of the coronary artery
• Coronary artery embolus
• Coronary artery thrombus

9
Assessment for Chest Pain

• Subjection
• Tightness, heaviness, squeezing, or crushing pain
  in the substernal area, which can radiate to the
  jaw, neck, left arm, or shoulder
• Determine if pain is precipitated by an event
  (exercise, stress or exertion)
• Is the pain relieved by rest or drugs?
• Is there any predisposing factors?
• URI, PE, Hypoxemia, blood loss
• Patient may experience anxiety and feeling of
  doom

10
Assessment for Chest Pain, cont.

• Objective
• Dyspnea
• N/V
• Profuse diaphoresis
• Adventurous breath sounds
• Tachycardia, decreased B/P, temp
• Elevation of cardiac enzymes (CPK, CPK-MB, AST,
  LDH, Troponin)
• EKG changes
• Results of any procedures completed

11
EKG Changes of an MI
12
Medical Treatment

• Early treatment is important
• Goal is to preserve myocardial tissue
• Nitroglycerin
• Dilates coronary arteries
• Morphine sulfate 2-4 mg titrated for pain
  relief
• decreases blood return to the heart
• decreases anxiety
• relaxes smooth muscle in the lungs
• has analgesic effect

13
Medical Treatment, cont.

• Oxygen at 2-4 L/min
• Thrombolytic therapy must meet criteria
• Streptokinase
• TPA
• Heparin
• ASA
• Lidocaine, Calcium channel blockers, Digoxin,
  Beta blockers, Dopamine, Dobutamine
• Angioplasty/Stent placement
• Coronary Artery Bypass Grafting
• Transmyocardial Lazer revascularization

14
Angioplasty
15
CABG
16
(No Transcript)
17
CABG
18
Nursing Interventions For MI

• Provide quiet, calm environment
• Keep client on bedrest for 24-48 hours
• Give medications as ordered analgesics, O2,
  Nitroglycerin
• Elevate head of bed
• Watch for any more chest pain
• Maintain IV line
• Monitor for signs of CHF, cardiogenic shock, and
  pulmonary edema
• Evaluate signs of MI
• Skin color, and temperature
• Monitor vitals
• Observe EKG for dysrhythmias
• Monitor fluid volume levels
• Check labs

19
Continued Care of MI

• Cardiac Rehab
• Begin as soon as patient is stable
• Individualized for need
• Involves stages
• Includes nurse, physician, nutritionist, physical
  therapy and social workers
• Home care
• Teach about medications
• Include follow-up with physician
• May need to teach about CAD
• Teach modification of risk factors weight, diet,
  smoking, exercise, etc.
• Notify of any chest pain

20
Cardiopulmonary Arrest

• Sudden cessation of hearts pumping function,
  stopping ventilation and circulation
• Rapidly fatal if untreated
• Accounts for 350,000 deaths/year
• Prompt treatment and early hospitalization
  necessary to prevent death
• Causes
• MI
• V-Fib
• Heart failure
• Electrolyte imbalances
• Hemorrhage
• Electrical shock

21
Objective Symptoms

• Unconscious
• Absence of pulse and respirations
• Absence of heart sounds
• Pupillary dilation
• Cyanosis

22
Diagnostic Tests

• History
• Physical
• EKG
• Enzymes after emergency treatment

23
Implementation

• CPR
• ABCs
• IV for administration of drugs
• ABGs frequently
• Give Lidocaine, etc.
• Watch for hypoxia, arrythmias, acidosis, and
  hypokalemia
• Monitor labs
• Assess LOC, skin color, temp, pulses, seizures,
  pupil changes
• Observe for complications (rib fractures,
  tamponade, pneumothorax)
• Give emotional support to the family