NURS 460 - CV Disorders (Exam 1) (haley_huff4)

What is acute coronary syndrome?

All inclusive term for conditions that cause chest pain d/t insufficient blood supply to cardiac muscle

What does ACS range from?

Non-ST elevation ACS to STEMI

What is the patho behind ACS?

Development of fatty plaques in coronary arteries, growth of plaques leads to narrowing of vessels limiting delivery of O2 to heart muscle

What happens in early atherosclerosis?

Small lipoproteins penetrate the vascular endothelium and gather into the intimal lining of the vessel

What does an unstable plaque consist of?

Large lipid core, many lipid-laden macrophages, thin fibrous cap

What happens when the fibrous cap ruptures?

Thrombogenic contents spill into the pt's blood causing platelets to aggregate and stick at the site of injury progressing to a complete occlusion of the coronary vessels

What is the cause of adverse cardiac ischemic events in all of ACS?

Platelet-rich thrombi

What does the initial occlusion of coronary arteries cause?

Unstable angina

Describe the development of a NSTEMI

Platelets continue to aggregate and cause blockage of smaller vessels

Describe the development of a STEMI

The plaque rupturing induces formation of thrombin, which converts fibrinogen into fibrin causing the thrombus to stabilize and fully occlude the coronary vessel

What are the non-modifiable risk factors of CAD?

Age, gender, heredity

What age is a RF for CAD?

75+

Which gender is more likely to develop CAD?

Men

Which ethnicity is at a higher risk of having CAD?

AA

What are the three types of angina?

Stable, variant, unstable

What is the etiology of stable angina?

Myocardial ischemia ACS

How long does stable angina last?

5-10 minutes, aggravated with exercise, cold, eating, stress

How is stable angina relieved?

Rest and nitroglycerin

How is stable angina treated?

Nitro, ASA, BBs, CCBs, ACEIs

What is the etiology of unstable angina?

Ruptured or thickened plaque with platelet and fibrin thrombus, causing coronary obstruction

What are characteristics of unstable angina symptoms?

Increasing, occurs at rest or with minimal activity, unresponsive to nitro

How is unstable angina treated?

NTG, BBs, tPA, oxygen, clopidogrel, morphine, statins, ASA

What causes variant angina?

Coronary vasospasm

When does variant angina occur?

At rest

What triggers variant angina?

Smoking

How might variant angina occur on an ECG?

Transient ST-elevation

What is variant angina often associated with?

AV block or ventricular arrythmias

How is variant angina treated?

CCBs, long-acting nitrogen preparations

What might unstable angina lead to?

NSTEMI

When does an MI occur?

Occurs when the heart muscle is abruptly deprived of oxygen, following coronary plaque rupture

What are the three phases of myocardial O2 deprivation?

Ischemia - lack of oxygen
Injury - injured from lack of oxygen
Infarction - tissue death from lack of oxygen

How long does it take for ischemia to occur within coronary occlusion?

10 seconds

Describe how ischemia can lead to MI

During ischemia, the cells decrease activity to conserve energy. -\> Several minutes after loss of contractile ability, the heart muscle is not deprived of its glucose stores and switches from aerobic to anaerobic metabolism -\> buildup of excessive lactic acid

How is an MI characterized?

-By wall of ventricle on which it occurs
-Anterior, lateral, septal, inferior, or posterior

What determines how much damage is done with an MI?

The higher, more proximally the occlusion in a coronary vessel, the more muscle damage

How does ischemia affect an ECG?

T wave inversion

How does injury affect an ECG?

ST elevation

How does infarction affect an ECG?

Q waves

What is a transmural MI?

involves full thickness of ventricle that yields ST elevations on electrocardiogram, negative Q waves. known as STEMIs

What is a STEMI aka?

Transmural or Q-wave

What is a NSTEMI aka?

Subendocardial, non-Q-wave

What does ST elevation indicate?

Myocardial infarction

What is a Q-wave indicative of?

Transmural MI; entire thickness of the heart wall

What does a NSTEMI indicate?

Ischemia

What does T wave inversion indicate?

Ischemia, NSTEMI

What are the characteristics of pain with MI?

Severe crushing or squeezing, radiates down left arm or up to jaw, not relieved by rest or nitro

When is pain classified as angina?

Lasts 15 minutes and disappears with rest

What are the six steps for assessing pain in a suspected MI?

Associated symptoms
Precipitating factors
Quality
Region, radiation, risk factors
Severity
Timing

What are atypical s/sx of MI?

N/V, diaphoresis, palpitations, dyspnea

What are other signs of MI in addition to pain and atypical?

Cool clammy skin, low-grade fever

What causes cool, clammy skin in MI?

Vasoconstriction

What causes a low-grade fever in MI?

Systemic response to inflammation

Which populations have atypical presentations of MI?

Women, diabetics

How might women present with MI?

SOB, fatigue, lethargy, indigestion, anxiety, numbness and tingling of back or left side of chest

What position should a patient with suspected MI be in?

Semi-Fowler's

How long within arrival to the ED should an EKG be obtained?

10 minutes

What labs are obtained when someone presents with chest pain?

Troponin I, CKMB, CK, INR, electrolytes

What is the first med given for chest pain in the ED?

ASA

When can NTG not be given when someone has chest pain?

If SBP is below 90

When are ACEIs given for chest pain?

If s/sx of CHF are present

What are the emergency meds for chest pain?

Morphine
Oxygen
NTG
ASA
BBs

How much morphine is given for chest pain?

2 mg IV

Why does morphine help with suspected MI?

Dilates coronary arteries

How much O2 is given for chest pain?

4 L NC or 100% NRB

How is nitro given in the ED?

Usually SL

Why are BBs given for chest pain?

Slow HR to restore oxygenation

What kind of EKG is done in the ED?

12-lead

Which vessel supplies blood to the inferior part of the heart?

Right coronary artery

Which leads reveal issues with the RCA?

II, III, aVF

Where does the RCA supply blood?

Inferior

What do leads II, III, and aVF see?

RCA

What supplies blood to the septum?

Left anterior descending artery

To where does the LAD artery supply blood?

Septum, anterior, lateral

Which leads reveal issues with the LAD artery at the septum?

V1 and V2

What do leads V1 and V2 see?

LAD artery, septum

Which vessel is affected in an inferior MI?

RCA

Which vessel is affected in a septal MI?

LAD

Which vessel supplies the anterior part of the heart?

LAD

Which leads reveal issues with the LAD on the anterior part of the heart?

V3 and V4

Which vessel is affected in an anterior MI?

LAD

What do leads V3 and V4 show?

LAD, anterior

What supplies blood to the lateral wall of the left ventricle?

LAD, circumflex

Which vessel is affected in a lateral MI?

LAD, circumflex

Where does the circumflex artery supply blood?

Lateral wall of left ventricle

Which leads show issues with the lateral wall of the left ventricle?

I, aVL, V5, V6

What does CK determine?

Size and timing of the MI

What marker is specific to myocardium?

CK-MB

What can Troponin-T determine?

MI size after 72 hours

What are normal troponin-T values?

What is the most accurate marker of myocardial injury?

Troponin-I

What is the normal troponin-I value?

How is troponin-I assessed? Why?

Serial testing every 3-4 hours until it peaks then starts to decline; may not increase for 6 hours after injury

Is myoglobin a strong indicator of MI?

Can be, but is not specific to cardiac muscle

What is CRP?

Acute-phase reactant produced by the liver in response to inflammation

When does CRP peak following MI?

1-3 days

What is the purpose of fibrinolysis?

Dissolves clot in the coronary artery restoring blood flow

What are the requirements for fibrinolysis?

STEMI, symptom onset

What kind of drugs are "plases"?

Fibrinolytics

When should fibrinolysis ultimately begin?

Within 30 minutes of arriving at ED or within 3 hours of symptom onset

What are contraindications for fibrinolysis?

Active bleeding, hx of AVM or cerebral aneurysm, hx of cerebral hemorrhage, pregnancy, recent ischemic stroke, uncontrolled HTN, suspected aortic dissection, traumatic CPR