2.2 Cardiovascular, Acute Coronary Heart Disease Flashcards
Acute Myocardial Infarction
Discuss coronary artery disease and angina pectoris
Coronary Artery Disease:
Impaired blood flow to the myocardium, usually caused by atherosclerotic plaque in the coronary arteries. Can be asymptomatic or may lead to angina pectoris, acute coronary syndrome, myocardial infarction, dysrhythmias, heart failure and death.
Angina pectoris:
Chest pain resulting from reduced coronary blood flow which causes imbalance myocardial blood supply and demand
May be due to coronary heart disease, atherosclerosis or vessel constriction
Acute Myocardial Infarction
Discuss pathophysiology of AMI
Patho AMI:
Blood flow to a portion of cardiac muscle is completely blocked, resulting in prolonged tissue ischemia and irreversible cell damage. Coronary occlusion is usually caused by ulceration or rupture of a complicated atherosclerotic lesion. When atherosclerotic lesion ruptures or ulcerates, substances are released to stimulate platelet aggregation, thrombin generation. Vessel constriction and a thrombus (clot) forms, occluding the vessel and interrupting blood flow to the myocardium
Acute Myocardial Infarction
Identify assessment findings related to AMI and ACS
Pain:
heaviness/pressure/burning/tightness
substernal or precordial; may radiate to neck, arm, jaw
indigestion, upper back pain, atypical
Skin:
ashen, cool, clammy
Cardiovascular:
Initial elevation of BP and HR but BP can drop with decrease cardiac output
Shock= reduced perfusion of organs (brain, liver, kidneys, etc)
Abnormal heart sound S3 and S4, murmurs
Nausea and vomiting
Fever:
inflammatory process caused by cell death, increased WBC
Anxiety:
impending doom or denial
Acute Myocardial Infarction
Describe the diagnostic process of ECG
ECG changes evolve over course of MI
ST depression= ischemia (inadequate blood supply)
ST elevation= injury
Q wave= infarction (obstruction of the blood supply)
T wave inversion= ischemia or injury
Ischemia: an inadequate blood supply to an organ or part of the body, especially the heart muscles
Infarction: obstruction of the blood supply to an organ or region of tissue, typically by a thrombus or embolus, causing local death of the tissue
ECG leads determine location of MI
ECG within 10 min of arrival to ER
**infarcted tissue doesn’t conduct normally
Acute Myocardial Infarction
Describe the diagnostic process of cardiac enzymes
Cardiac enzymes (markers): Proteins released when myocardial cells die, they determine the timing and severity of MI. Tests are repeated q6-8 hours for 24 hours
Myoglobin: first detectable but nonspecific with limited use (not often used)
Troponin: Elevates in 2-4 hours, peaks in 10-12 hours, return to baseline within 10 days. MOST specific indicator of MI
CKMB/CK ratio (heart specific/total body): Elevates in 4-8 hours, peaks 18-24 hours, return to baseline within 3 days.
Increased CK= muscle injury
Increased CK-MB= cardiac muscle injury
Acute Myocardial Infarction
Describe the diagnostic process of stress testing
Stress testing
When cardiac enzymes are negative a stress test is ordered
Many stable outpatients have stress tests for initial screening
Exercise testing on treadmill and monitored
Medication induced stress when a patient can not walk on treadmill (meds: Persantine, dobutamine)
Myoview: nuclear isotope tracer (thallium) injected to evaluate UPTAKE into heart muscle
-assess coronary blood flow, perfusion to the myocardium
-scanned with exercise, then repeated at rest (2-3 hrs later)
Acute Myocardial Infarction
Describe the diagnostic process of echocardiogram
Echocardiogram:
Sonographic imaging of the heart
Transthoracic (more common) or Transesophageal, requires sedation
Evaluation of cardiac anatomy and function:
Muscle function/wall motion
Muscle thickness
Valve function
Chamber size and shape
Pericardial fluid
Thrombus
**does not evaluate vessels or conduction
Acute Myocardial Infarction
Describe and give rationale for nursing and medical interventions including medications
Nursing interventions for AMI
Anticipated orders: telemetry, serial ECG serial cardiac enzymes oxygen IV access (2 IV's, 18 g) bedrest to reduce cardiac workload; BSC light diet, small frequent meals but NPO initially diagnostic testing cath lab ASAP with STEMI
Medications:
Nitro- vasodilation, reduced cardiac workload, reduced anginal pain, improves perfusion. First line!
Morphine- drug of choice is nitro is not relieving pain, reduces anxiety, reduces cardiac workload
Aspirin- prevents platelet aggregation, chew for rapid buccal absorption
Heparin- does not lyse clots, prevents further buildup of thrombus
Beta Blocker (“olol”)- reduced O2 demand by reducing HR, BP and contractility, limit size of infarct, reduce risk of reinfarction and arrhythmias. Not used in shock state
Ace Inhibitors (“pril”)- prevents ventricular remodeling and heart failure, reduces mortality
Antidysrhythmic (amiodarone)- if needed, dysrhythmias are common
Cholesterol meds- underlying atherosclerosis
Laxatives- to avoid straining with BM
Acute Myocardial Infarction
Discuss inter-professional collaboration, including providers and cardiac rehab
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Acute Myocardial Infarction
Complications of AMI
DYSRHYTHMIAS
AMI Dysrhythmias:
Most frequent complication
Infarcted tissue is arrhythmogenic, alters impulse generation and conduction
PVC’s very common d/t ventricular irritability
Vtach and Vfib, frequent cause of sudden cardiac death, less common. Shockable rhythms
AV Blocks, common with anterior wall infarction, brady, right sided
Bradycardias, common with inferior wall infarction
Acute Myocardial Infarction
Complications of AMI
HEART FAILURE AND PULMONARY EDEMA
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Acute Myocardial Infarction
Complications of AMI
PERICARDITIS
Pericarditis
Inflammation of pericardium: dual membrane sac, holds 30-50ml serous lubricant fluid. Inflammation may cause scarring and become chronic
Infectious causes: vial most common, heals with time
Noninfectious causes: many, including myocardial injury, autoimmune disease, cancer
Pericardial effusion: more than 50ml of fluid
Cardiac Tamponade: pressure around heart and unable to pump= decreased BP, narrow pulse pressure, muffled heart tones, JVD, anxiety, signs of shock
Assessment: Chest pain: acute and sharp, worse on inspiration and relieved with leaning forward. Pericardial friction rub Mild fever Tachycardia Increased WBC and SED rate Slight increase in cardiac enzymes
Medica management:
Tylenol for fever
NSAIDS for inflammation, steroids if needed
Treat underlying cause
Surgical management:
Pericardiocentesis: needle aspiration
Pericardial window: removal of small rectangle of the pericardium
Pericardiectomy: removal of entire pericardial sac, typically requires a sternotomy
Acute Myocardial Infarction
Complications of AMI
MITRAL VALVE DYSFUNCTION and other structural defects
Mitral Valve:
Papillary muscle rupture
-Ischemia= papillary muscle dysfunction or rupture
-Sudden valve failure, typically mitral regurgitation, loud murmur, surgery immediately
Necrotic muscle= scar tissue, stiff, noncompliant
Ventricular aneurysm= scar tissue displaces outward
Myocardial rupture
Acute Myocardial Infarction
Discuss rationale for hypothermia and nursing interventions
Hypothermia therapy:
Protects brain from cellular injury
Initiated after Vtach or Vfib arrest (when pulse is recovered but patient still unresponsive)
Goal:
Reduce metabolic rate and O2 demand
Stabilize cell membrane
Reduce ischemic damage and reperfusion injury caused by inflammation
Goal temp: 32-34 C, cold saline, cooling blankets
24 hour treatment, then gradual rewarming
Complex ICU nursing care: Ventilator- sedation and analgesia Fluid and electrolyte management Cardiac monitoring Protect skin- necrotic, bleeding, pressure Monitor for bleeding and kidney injury
Cardiac catheterization
Identify indications for right and left catheterization
Coronary angiography:
Gold standard for looking at coronary anatomy
Dye and fluoroscopy visualization
Right heart cath:
Measures pressures in right side of heart and lungs
Venous puncture typically in groin
Left heart cath:
Determine location and severity of blockages
Arterial puncture, typically wrist or groin
Ventriculogram:
Measures left ventricular function
Requires additional dye
Cardiac catheterization
Describe the procedure
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Cardiac catheterization
Identify and give rationale for nursing interventions pre and post cath
Pre cath:
Baseline assessment
Post cath:
Neuro
Assess site:
-groin- bedrest 4-8 hrs w/ leg straight, HOB <30 degrees, worried about pseudoaneurysm (not true aneurysm but an injury to the lining of the artery where blood leaks out into the outer most layer, bulging, painful
-radial- pressure bands, no mobility restrictions
Distal circulation
Pain/symptoms
Cardiac rhythm
Restenosis (artery closes again after corrective surgery)
Reperfusion, may also cause angina (ex: foot falls asleep, tingling, pain)
Monitor CBC, BMP and I/O
Medications:
Nitrates
Calcium channel blockers (“dipine”, open arteries)
Antiplatelets (can be dual antiplatelet therapy)
Acute Coronary artery disease
Discuss the use of thrombolytics and nursing care
Thrombolytics (clot busters):
Used when there is no access to cath lab for PCI
Reperfusion is the goal
Treat and transfer to a PCI facility for angiography and PCI
Medications: Alteplase (tPA), Reteplase (rPA), Streptokinase within first 6 hours of symptoms onset
Nursing care: HOB <15 degrees, bedrest Cardiac monitoring Monitor for bleeding AVOID injections, catheter placement r/t bleeding after thrombolytic is administer (bleeding risk).
Acute Coronary artery disease:
Revascularization: Percutaneous Coronary Intervention (PCI)
Discuss the use of angioplasty and complications
Angioplasty is a procedure used to open blocked coronary arteries (balloon inflation of artery) caused by coronary artery disease. It restores blood flow to the heart muscle without open-heart surgery
Complications: Dissection- artery damage Vasospasm- artery irritation Dysrhythmias Restenosis- artery closes again CVA- stroke risk CIN- contrast induced nephropathy
Acute Coronary artery disease
Revascularization: Percutaneous Coronary Intervention (PCI)
Discuss the use of stents
Coronary stents are now used in nearly all angioplasty procedures. A stent is a tiny, expandable metal mesh coil. It is put into the newly opened area of the artery to help keep the artery from narrowing or closing again.
Complications: Dissection- artery damage Vasospasm- artery irritation Dysrhythmias Restenosis- artery closes again CVA- stroke risk CIN- contrast induced nephropathy
Acute Coronary artery disease
Revascularization: Percutaneous Coronary Intervention (PCI)
Discuss the use of atherectomy
Atherectomy remove plaque buildup from an artery. Removing this plaque allows blood to flow more freely through the artery.
An atherectomy often treats artery blockages that contain plaque — fatty substances made up of cholesterol, fats, calcium, and other substances.
Unlike an angioplasty, which moves plaque to the side of the artery, an atherectomy completely removes plaque from the artery
Complications: Dissection- artery damage Vasospasm- artery irritation Dysrhythmias Restenosis- artery closes again CVA- stroke risk CIN- contrast induced nephropathy
Coronary Artery Bypass Grafting (CABG)
Revascularization
Identify indications for CABG
CABG indications:
Complete occlusion and wire cannot pass
Multivessel disease (3 or more vessels blocked)
Left main coronary artery disease
Failed PCI stent
Severe left ventricular dysfunction, low ejection fracture
DM (prone to stents blocking back up)