CAD and ACS - Unit 2 AH3

what are non-modifiable and modifiable cardiac risk factors

• non-modifiable:

  • age

  • gender

  • family history

  • race

• modifiable:

  • smoking

  • cholesterol/lipids

  • weight

  • diabetes mellitus

  • diet

  • physical activity

  • BP management

What is coronary artery disease (CAD)

• atherosclerosis (plaque) forms and occludes coronary artery

  • causing

    • unstable angina

    • myocardial infarctions

    • sudden cardiac death

• reduced blood flow through coronary microvasculature

  • coronary artery blood vessels don’t have plaque (occlusion), but damage to the inner walls of the blood vessels can lead to spasms and decrease blood flow to the heart muscle

  • ischemic symptoms - lack of blood flow and oxygen to the tissue leading to tissue death

CAD: clinical manifestations

• stable angina

  • chest pain or discomfort that is associated w/ physical activity

  • linked to fixed plaque formations and is predictable

  • symptoms are often alleviated w/ rest and/or medications

• unstable angina

  • refers to chest pain that can occur at rest

    • this type of angina can be brought on by physical activity as well

  • of the two types of angina, unstable angina is the most concerning

  • identified as the initial phase of acute coronary syndrome (ACS), defined as a disorder caused by an acute decrease in blood flow through the coronaries, to the myocardial tissue, and can be a precursor to MI

  • Should be treated as an emergency

• prinzmetal’s angina

  • a variation of unstable angina is Prinzmetal’s, or variant, angina

  • the blockage of blood flow in this disorder is caused by coronary artery spasm rather than plaque formation, but atherosclerotic changes are commonly present

  • it typically occurs at rest and in clusters at night between midnight and 8 am

CAD: medical management - diagnosis

• labs

  • total cholesterol, triglycerides, LDL, HDL, CK, CK-MB, troponin

• electrocardiogram (ECG)

• exercise or chemical stress test

• coronary angiography (left sided heart cath)

  • gold standard for diagnosis

    • determines if percutaneous transluminal coronary angioplasty (PTCA) is an option (aka a cardiac stent placement)

CAD: medical management - medication

• stop aggregation of blood components to endothelium

• control factors leading to endothelial damage

• relief or symptoms

so they don’t have blood clot next to the plaque buildup and cause cardiac event

CAD: surgical management

• percutaneous transluminal coronary angioplasty (PTCA) aka percutaneous coronary intervention (PCI)

  • performed in the cardiac cath lab

  • monitored anesthesia care (formerly known as conscious sedation)

  • catheter with a small balloon on its tip is advanced under fluoroscopy through a suitable artery, commonly the femoral or radial, to the area with atherosclerotic plaque

  • the balloon inflated and deflated to open the lumen of the artery

  • once the lumen is open, a stent may be advanced to the location to hold the artery open and maintain adequate blood flow

  • will need 3 consent forms

    • PTCA consent form

    • PCI consent form

    • blood consent form

• coronary artery bypass grafting (CABG)

  • performed in the operating room under general anesthesia

  • blockages in coronary arteries are bypassed using other arteries from the chest or arm or veins from the legs

  • a large incision through the sternum is made

  • cardiopulmonary bypass (CPB) is begun through large catheters in the vena cave or right atrium and aorta. a CPB provides continuous gas exchange and perfusion while the heart is stopped to provide a still, bloodless field for surgery

  • then arteries or veins being used as bypasses are surgically attached to the diseased coronary, creating an alternate path for blood to flow around the blockage

  • **Pathway to go around the blockage, leave the blockage alone​

CAD: medical management - lifestyle management

• maintain healthy body weight

• diet

• physical activity

• smoking cessation

• screening and treatment for depression

• refraining from excessive alcohol use

• cardiac rehabilitation

CAD: complications

• myocardial infarction (acute coronary syndrome)

• dysrhythmias

• heart failure

acute coronary syndrome

• STEMI (ST elevation MI)

  • infarction with complete obstruction of blood flow

  • unstable angina

  • present w/ ischemic symptom → angina, dyspnea, vital sign changes

  • STEMI on 12 lead EKG, 1 millimeter or higher ST elevation in 2 or more leads is a MI w/ complete obstruction

• Non-STEMI (non st elevation mi)

  • ischemia w/ partial obstruction of blood flow

  • unstable angina

• both may present w/ unstable angina

myocardial infarction: clinical manifestations

• chest pain (angina)

  • unstable

  • may start as stable and turn into unstable

• be mindful of nonspecific symptoms:

  • epigastric discomfort

  • N/V

  • diaphoresis

  • syncope

  • SOB

  • pain between shoulders/jawline

• females typically have nonspecific symptoms***

  • not always 10/10 crushing chest pain like in males

MI: medical management - diagnosis

• lab tests

  • Troponin: cardiac damage (specific to the heart)

  • CK (Creatine kinase): enzyme found in heart and skeletal muscle, high levels indicate muscular injury (not specific to the heart)

  • CK-MB (Creatine kinase - myocardial band): specific to the heart

  • Myoglobin: protein found in skeletal muscle and heart (not specific to the heart)

• diagnostic testing

  • ECG/EKG (electrocardiogram):

    • **gold standard for diagnosis of MI

  • echocardiogram: ultrasound of the heart looking at contractility and chambers

  • stress test: if active MI we will skip this step and go straight to cath lab

  • coronary angiography (aka heart cath lab)

difference between Troponin I and Troponin T

— always done in series, at least 3; then when positive, keep going until the peak

— first come in, then 1 hr, then 6 hr, then when they peak

— troponin does not rise for 3hr after MI

—NEED TROPONIN WHEN THEY FIRST COME IN, AN HOUR LATER AND THEN AGAIN BASED ON PROTOCOL AND IF POSITIVE KEEP TESTING UNTIL THEY PEAK

---

• Troponin I

  • is specific to the heart muscle damage it only comes from myocardium

  • normal level: <0.04 ng/mL

  • MI: >0.04 ng/mL

• Troponin T

  • comes from skeletal muscle and myocardium

  • normal level: <0.01 ng/mL

Emergent STEMI Treatment

• aspirin

• nitroglycerin

• morphine

• supplemental O2 if sats <90%

• consider load w/ P2Y12 inhibitor

Aspirin

• the 1st med prioritized in ACS

• onset of action 1-7.5 min if chewed

• initial dose 325 mg CHEWED, then 81 mg indefinitley

• disables platelet aggregation (blood thinner)

• POTENT!!!! (strong)

• monitor for intolerance

  • s/s: flushing, itchy, rash, nassal congestion, asstham exacerbation

  • plavix can be used as an alternative for intolerance

• shouldn’t take w/ other nsaids

  • can become thrombotic

• will go on baby asprin everyday indefinitely

Nitroglycerin

• potent vasodilator and venodilator

• reduces preload and ventricular wall tension

• decreases myocardial O2 consumption

• sublingual, spray or intravenous

  • sublingual 0.4 mg Q 5 min x 3, then assess the need for IV NTG

• monitor for hypotension, HA is common

• do not give to pts w/ right ventricular infarction or use of other phosphodiesterase (PDE-5) inhibitors (VIAGRA OR CIALIS) {**can’t be given for erectile dysfunction drugs because they are vasodilators, so it will bottom out the BP}

  • caution w/ inferior wall MI

  • they are preload dependent, so if they don’t receive enough blood to return to the right side of the heart, they will go into cardiac arrest

• Important to ask if pt had nitro prior to admission

• BP goes down w/ nitro (keep checking BP), so if BP is low before giving nitro try to get it increased before giving nitro

Morphine

• use as adjunct therapy (along with) to nitroglycerine

• small incremental doses

  • 1-2 mg IV q 5-15 min if CP unrelieved by NTG

• potent analgesic (pain) and anxiolytic (anxiety)

• causes venodilation and reduces preload, mild afterload reduction

• decreases workload of heart

  • anxiolytic of choice

  • use cautiously in inferior wall MI

  • avoid in right ventricuclar MI

  • increased mortality in a large registry

  • more research needed

• don’t use every time, but consider if nitro doesn’t work

oxygen

• Administer supplemental oxygen only when:

  • the oxygen saturation falls below 90%

  • respiratory distress is present

  • other high risk features for hypoxemia are present

• reserved for hypoxemia

  • hyperoxemia likely perpetuates oxidative injury after MI

Acute STEMI - PCI

• gold standard for ST elevation MI: revascularization/PCI

• door to balloon time goal: 90 min!!!

• more trans-radial approach

• monitor kidney (urine output, and BUN and Creatinine lvls) - dye load

  • there is so much dye put into pt during this procedure and can cause kidney failure

retroperitoneal bleed and hematoma (RBH)

• femoral approach

• retroperitoneal space can hold 4L of blood which is almost all pt blood in body so we need so look out for early s/s

  • gonna need blood or MTP

• signs:

  • tachycardia

    • may not see d/t beta blockers

  • hypotension

  • back pain, groin pain, flank ecchymosis (late sign)

• tx:

  • stat H/H, coags if applicable

  • may medically manage (hold pressure) or surgical repair (<10%)

  • percutaneous intervention w/ balloon tamponade

  • fluids, prepare to transfuse

fibrinolytic therapy

• pt can get fibrinolytic therapy until they can get pt to chest pain center to get to cath lab, we are trying to hold them over

• if unable to get to cath lab in a timely manner-

  • TNKase (tenecteplase)

    • same drug as for stroke, accept we are using it for emergency purposes in the coronary artery to bust the clot

  • rtPA (activase)

  • will still need to go to cath lab

• indications:

  • pain < 6 hrs

  • ST elevation > 1 mm in 2 or more leads

• nursing considerations:

  • bleeding is most common side effect

    • if bleeding occurs, discontinue all anticoagulants

    • monitor PT/INR/aPTT - prolongs both

    • monitor fibrinogen - decreased fibrinogen for up to 24*

    • reversal - cryoprecipitate and platelets

    • biggest area is cerebral hemorrhage

      • need frequent neuro assessments, monitor for bleeding, and avoid any additional needle sticks

  • frequent neurological assessments

  • avoid punctures

  • monitor urine output and BUN/creatinine

  • avoid invasive devices

  • avoid compressive devices

the “Big 5” discharge medications following ACS

• ASA: (indefinitely)

• P2Y12 receptor blocker: prevents clotting(at least 1 yr)

• beta blocker: (indefinitely)

• ACE-I (or ARB): EF <40% or anterior MI (indefinitely)

• Statin (high intensity indefintely)

• dual antiplatelet therapy is ASA and P2Y12 drugs

• continuing dual antiplatelet therapy for 1 yr is critical - important for pt education

myocardial infarction: complications

• heart failure

• arrhythmias

MI: nursing interventions - assessments

• vital signs and pulse oximetry:

  • tachycardia w/ a borderline low BP and decreased oxygenation saturation is a sign of inadequate CO and oxygen deliver

• characteristics of pain

  • location, radiation, duration, intensity, precipitating or alleviating factors; use a 1-10 pain scale — chest pain is an indication of MI. continued or changing pain characteristics can be indicative of a worsening condition

• ECG

  • ST-segment depression is indicative of ischemia

  • ST-segment elevation is indicative of injury

  • if present a Q wave is diagnostic for MI

• restlessness

  • may be found in early stages, but progression to severe anxiety and sense of doom is late stage symptom

• skin color and temp peripheral pulses, diaphoresis

  • decreased pulses and cold, clammy, pale skin are s/s of inadequate tissue perfusion and inadequate CO

  • activation of the sympathetic system w/ low co will stimulate diaphoresis

• monitor urine output

  • decreased or absent urine output is a sign of decreased renal perfusion related to decreased CO

• labs

  • assess troponin, CK, and CK-MB lvls

    • troponin is protein released from damaged cardiac muscle. it elevates w/in 4 hrs and can stay elevated for days

    • CK-MB, the CK isoenzyme marker specific to cardiac tissue, is released from the cells w/ cardiac muscle damage. Increased lvls can be seen at 3 hrs and remain elevated for as long as 36 hrs

MI: nursing interventions - actions

• administer oxygen

• insert two large-bore IVs

• administer meds as ordered - meds are essential to be given in a timely manned

  • aspirin and heparin - are given to prevent new clot formation

  • nitroglycerin SL - dilates the coronary arteries, increasing blood flow and decreasing pain

  • morphine - narcotic given for pain relief if nitro is not effective

  • beta blockers - decrease the sympathetic response to an MI, decreasing cardiac workload and oxygen consumption

  • fibrinolytics work to dissolve clots

• continuous ECG monitoring

  • electrocardiogram monitoring is essential to evaluate the evolution of the MI and the effectiveness of tx and to monitors for dangerous dysrhythmias that can occur

• bed rest

  • the pt may require bed rest as well as emotional rest to decrease oxygen and cardiac demands

MI: nursing interventions - teaching

• report s/s of MI

  • chest pain or discomfort or SOB

• medication education

  • purpose, dose, and side effects of meds

  • prescribed meds are to treat the effects of MI and prevent future MI’s

• american heart association “life’s simple 7”

  • no smoking

  • maintain a normal body weight

  • exercise for at least 150 min w/ moderate intensity activity, or 75 min of vigorous intensity activity, or a combination of each per week

  • eat healthy diet

  • maintain total cholesterol lvl less than 200 mg/dL

  • keep Bp less than 120/79 mm Hg

  • keep fasting blood glucose less than 100 mg/dL

EDUCATION!!!

• medication compliance

• don’t drink

• don’t smoke

• exercise

• manage weight

• heat healthy diet

• lower cholesterol / lipids

• reduce stress