Unstable Angina

Unstable Angina (UA)

• Progressive & unpredictable; change in previously established stable lesion.

• May last for 10 minutes or longer

• May occur at rest or during sleep.

• Indicates plaque instability; Stable lesion may rupture leading to constriction and thrombosis which can occlude and lead to MI.

• Not relieved by NTG SL X 3

UA includes

• UA includes ST depression and T wave inversion

Acute Coronary Syndrome (ACS) includes

• Includes UA and non-ST segment elevation myocardial infarction (NSTEMI) and ST segment elevation myocardial infarction (STEMI)

ACS

ACS

• Within the first 10 seconds of an occlusion, the heart is deprived on O2 and the glucose needed for aerobic metabolism and contractility.

• Anaerobic metabolism begins and creates lactic acid (limited O2)

• Irreversible damage begins after 20 minutes.

Myocardial Infarction (MI) Progression

• If injury is halted: then non Q wave MI or NSTEMI = partial muscle damage

• If not halted: thrombus forms then progression to myocardium (cell death, necrosis) = STEMI

• Collateral circulation assists in compensation of decreased circulation

ichemia

lack of o2

injury

muscle dying

infraction

muscle death

Anticoagulants

such as heparin or warfarin, slows down the body's process of making clots.

Antiplatelets,

such as aspirin and clopidogrel, prevent blood cells called platelets from clumping together to form a clot.

Thrombolytics

•  (…ase, Streptokinase, Alteplase [t-PA]) work by dissolving a major clot quickly

Clinical Manifestations

• Chest pain/pressure: heavy, tight, burning, crushing

• Pressure that radiates: neck, back, arm, jaw

• Dysrhythmia

• Dyspnea

• Diaphoresis

• N, V

• Acute Anxiety

• Fatigue/weakness

• Clammy, cool skin: vasoconstriction

Diagnostics (See CAD PPT)

• Cardiac Biomarkers

• Troponin T, I, and C

• CBC, BMP

• 12 lead ECG

• CXR

• Exercise Stress Test

• Pharmacologic Stress Test

• Echocardiogram or TEE

• Cardiac Catheterization

Interventions

• Oxygen 2L nc

• Pulse oximetry and frequent VS

• Cardiac Assessment

• Bedrest

• Telemetry monitoring

• IV access

• Medications

Thrombolytics

• …ase

• Acts directly on clots to cause lysis (not only in heart)

• ***Within 30 minutes of arrival to ED, not usually after 12 hours after symptoms and must have STEMI (complete blockage)

• Know contraindications (Table 37-16)

• Before thrombolytic→do all invasive procedures (draw labs, start 2 or 3 IV lines, insert foley)

• Thrombolytics with Heparin may be used

thrombolytic recommended dose

• Recommended dose is 0.9 mg/kg (not to exceed 90-mg total dose) infused over about 3 hrs with 10% of the total dose administered as an initial intravenous (IV) bolus over 1 minute (by MD).

Thrombolytic Contraindications

• No internal bleeding or bleeding tendency (liver failure, Vitamin K deficiency, disseminated intravascular coagulation, Hemophilia, von Willebrand disease)

• Cerebral hemorrhage

• Ischemic Stroke in the past 3 months

• Surgery (within 3 weeks)

• Presence of current trauma

• Severe uncontrolled HTN→BP > 180/110 mm HG

Thrombolytic Working?

• Reperfusion Signs:

• Chest pain stops

• May observe limited dysrhythmias

• ST segment returns to normal

• Cardiac markers peak and return to normal

Thrombolytic Working?

• side effects:

• Reocclusion: Further chest pain - do EKG

• Bleeding 

  • Gums or IV sites – Apply pressure

  • Drop in BP or increase in HR – Stop Med

  • Change in mental status – Stop Med 

  • Hematuria, Melena – Stop Med

Other Drug Therapy

• IV NTG

• Ace Inhibitors/ARBs

• Β Blockers

• Antidysrhythmics

• Lipid lowering

• Anticoagulants

• Antiplatelet

• Stool softeners

Anticoagulants…Heparin

• 25,000 Units in 250 mL D5W IV

• Heparin bolus given, followed by maintenance infusion on IV pump

• Prevents thrombus formation

• Therapeutic effect monitored by Partial Thromboplastin Time (PTT). Elevations are seen in patients on heparin therapy

• Watch for bleeding

• Antidote: Protamine Sulfate

Anticoagulants…Warfarin

• Given when baseline established with heparin

• Will discontinue heparin after warfarin begins

• Oral doses may vary

• Therapeutic effect monitored by prothrombin time (PT) and international normalized ratio (INR) 

• Watch for bleeding

• Antidote: Vitamin K

Interventions

• Cardiac Catheterization, Coronary Angiogram, Arteriogram 

interventions

• Identify, localize CAD

• Contrast dye is injected through the catheter. X-ray images are taken to highlight the arteries. 

• Balloon angioplasty and/or Stent placement thru femoral or radial artery

• Prep: 

  • Ask about dye allergies

  • Verify consent for procedure

  • NPO 6-12 hours prior

  • IV fluids Sedation given prior

treatment

• Treatment: Percutaneous coronary intervention (PCI): Balloon and Stent

  • Stents are thrombogenic = sticky.  

    • Bare metal = needs anticoagulant rest of life.  

    • Drug-eluting stent = medication on stent to prevent thrombosis.  Still need anticoagulants for about 6 mos.

Interventions…Cardiac Catheterization

Interventions…PCI Post-op

• Hematoma  Prevention 

• Compression device over artery. Vaso-seal/per-close/Femstop

• HOB 30 degrees or less

• Bedrest until following day if femoral

• Telemetry monitoring and freq VS checks

• Distal pulses checks frequently (q 15 mins/1st hr)

• I & O, ensure urine output adequate

• IV fluids to eliminate dye

• Encourage oral fluids to eliminate dye

• Assess for complications:

• Rupture of dilated artery

• Infarction due to plaque breaking off and occluding vessel

Interventions…Coronary Artery Bypass Graft (CABG)

• Requires sternotomy and cardiopulmonary bypass

• Uses arteries and veins for grafts 

• The internal mammary, radial artery, and the saphenous vein are also used for bypass grafts.  

• Note neurovascular checks on the respective extremity post-op. 

• CABG surgery remains a palliative treatment for CAD and not a cure.

Interventions…Intraaortic Balloon Pump (IABP)

• Sausage-shaped balloon placed in the aorta which inflates and deflates in synchrony with the cardiac cycle (ECG) to reduce afterload and left ventricular diastolic pressure while increasing perfusion of the coronary arteries.

• Short term use to decrease cardiac workload and improve organ perfusion

Interventions…IABP complications

• Site infection

• Arterial trauma or hemorrhage

• Thromboembolism

• Pneumonia due to immobility

Interventions…Ventricular Assist Device (VAD)

• Placed internally or externally, replacing the pumping action of the left ventricle.  Blood is shunted from the left atrium to the aorta.

• Used for longer term support, but temporary

• Used most frequently for failure to wean from cardiopulmonary bypass after surgery

• May be bi-ventricular

Interventions…VAD

Remodeling

• Changes occur in the left ventricular myocardium that lead to progressive decline in left ventricular performance. 

• Ultimately, ventricular remodeling may result in diminished contractile (systolic) function and reduced stroke volume

COMPLICATIONS of MI

• Dysrhythmias  (freq occur-80-90% of pts)

• Heart Failure

• Cardiogenic Shock (O2 and nutrients are inadequate to cardiac tissues)

• Papillary Muscle Dysfunction infarct at mitral valve

• Ventricular Aneurysm or Rupture (heart wall thins and bulges out)

• Pericarditis (inflammation of the pericardium)

Cardiac Rehabilitation

• During activity – monitor bp/pulse.  Check for any increase greater than 20 mm hg or chest pain-intolerance

• Cardiac Rehab goal is to change lifestyle to modify risk factors

• CAD is a chronic disease

Go to ED if…

• Onset of sob/wheezing/racing heart

• Onset of new slow pulse rate

• Weight gain of 3 lb in 1 week

• Dizziness, faintness, extreme fatigue

• Chest pain with associated symptoms

• CP that is not relieved after 15 minutes/or 3 ntg.

Dilitiazem is used to treat variant angina (Prinzmetal’s) because it does which of the following:

A. Lower blood pressure

B. Slow the heart rate

C. Slow conduction across the myocardium

D. Relax arterial smooth muscle in the coronary arteries

Why is Captopril prescribed for clients who have experienced a recent MI:

A. To restore blood supply to the myocardium

B. To increase myocardial oxygen demand

C. To reduce post-MI Mortality

D. To reduce acute pain associated with MI

A patient is admitted to the cardiac care unit with a diagnosis of Acute Coronary Syndrome after experiencing a sudden onset of chest pain 4 hours ago. The first Troponin-I level is within normal limits. The nurse recognizes that this patient:   

A. Has not experienced a myocardial infarction. 

B. Should have a second Troponin-I  level drawn in 6 hours.

C. Should have a second Troponin-I level repeated immediately. 

D. Likely experienced a myocardial infarction within the past 24-48 hours.

During the administration of a thrombolytic

agent to a patient with an acute MI, the nurse should stop the drug infusion if the patient experiences

A. Bleeding from the gums.

B. Surface bleeding from the IV site.

C. A decrease in level of consciousness.

D. A nonsustained episode of ventricular tachycardia.

A patient is scheduled for coronary angiography and possible percutaneous coronary intervention (PCI) the nurse explains to the patient that it is used to:

A. Determine structural defects in the heart

B. Locate any coronary artery obstructions and give thrombolytic agents.

C. Measure the amt of blood pumped from the heart

D. Visualize any coronary artery blockages and dilate any obstructed arteries.

A client is receiving NTG IV.  The nurse should monitor for the most common side effect which is:

A. Drowsiness

B. Headache

C. Hypotension

D. Nausea

The nurse adjusts the plan of care for a client who is receiving propranolol to include increased monitoring of:

A. Heart rate

B. High blood pressure

C. Glucose

D. Potassium

Which of the following may indicate successful reperfusion after receiving a thrombolytic?

a. Negative creatine phosphokinase isoenzymes

b. Q wave formation

c. Atrial fibrillation

d. Normalization of ST segment

The older patient with coronary artery disease (CAD) is more likely to have what symptom if experiencing cardiac ischemia?

a. Syncope

b. Dyspnea

c. Chest pain

d. Depression

The provider diagnoses the patient with acute stable angina. The provider prescribes the patient NTG SL 5 mg for discharge and instructs him to see his cardiologist. What instructions should be included in teaching the patient about this newly prescribed medication? Select all that apply. 

a. Take 3 tabs 5 mins apart when you feel chest pain. 

b. Take 1 tabs 5 mins apart X 3 when you feel chest pain. 

c. Keep the medication in your pants pocket. 

d. If you take 3 tablets and your chest still hurts, call 911. 

e. Discontinue the medication if it gives you a headache. 

The cardiologist asks the nurse to schedule the patient for a diagnostic cardiac catheterization in the femoral area. Which instructions are the nurse’s highest priority at this time? Select all that apply.

a. Verify consent for the procedure. 

b. Question the patient about any dye allergies. 

c. Tell the patient that metformin should be withheld the day of the procedure and 48 hours afterward. 

d. Shave the patient’s right femoral groin to prepare the catheterization site.

e. Instruct the patient to complete the lab studies in the next day or two.