H&I 5 Exam 2

Perfusion, Fluid & Electrolyte, and Tissue Integrity

CAD

coronary artery disease

What is CAD?

Often caused by atherosclerosis (plaque formation) —> narrows/occludes arteries

• —> insufficient blood, O2, & nutrients reaching to ❤ muscle

• can lead to both chronic stable angina & acute coronary syndromes (ACS)

What is the pathophysiology of CAD?

Endothelial injury → lipid buildup → plaque → narrowing → ↓ oxygen supply → ischemia → plaque rupture → clot → MI.

ACS

acute coronary syndrome

What is ACS?

Occurs when blockage or severely narrowed artery (from CAD) reduces or stops blood flow to the muscle of the ❤

• the blockage is caused by atherosclerotic plaque in coronary arteries rupturing —> platelet aggregation (“clumping”), thrombus formation (“clot”), & vasoconstriction

Ex:

• Unstable angina

• ST-Elevation Myocardial Infarction (STEMI)

• Non-ST-Elevation Myocardial Infarction (NSTEMI)

ACS examples

Stable Angina

Occurs w exercise or emotional stress —> relieved by rest or nitroglycerin

Unstable Angina

Occurs w exercise or at rest —> increases in occurrence, severity, & duration

Why is angina a concern?

• Ischemia —> insufficient oxygen to the myocardium to meet demands

• Infarction (necrosis, or cell death) occurs when severe ischemia is prolonged and decreased perfusion causes irreversible damage to tissue

MI VS Angina

Pain unrelieved by rest or nitro. & lasts >15min differentiates an ___ from ___

Nitroglycerin MOA

Nitroglycerin is a potent venous vasodilator → ↓ preload → ↓ cardiac workload → ↑ coronary blood flow = relief of chest pain.

How many doses of Nitro. can we give a pt?

3 doses, 5 min apart

• PO tablet

What do we need to monitor when administering Nitro.?

BP bc main side effect is hypotension & don’t want to admin. if SBP is <100mmHg!!

• once in hospital, give infusion

• pt may have complaints of HA

2 Types of MI

• NSTEMI

• STEMI

What happens to the body during an MI?

1. Atherosclerotic plaque ruptures inside a coronary artery.

2. Platelets aggregate → thrombus forms → vasoconstriction worsens the blockage.

3. Blood flow drops 80–100% → myocardium becomes ischemic within seconds.

4. After 20–40 minutes of sustained ischemia → irreversible cell death (necrosis).

5. The necrotic area cannot contract → ↓ cardiac output.

6. Electrical instability develops → dysrhythmias (V‑tach, V‑fib).

7. Inflammatory response begins → enzymes leak into bloodstream (troponin, CK‑MB, myoglobin).

MI S/S in MALE

• N/V

• Jaw, neck, or back pain

• Pressure or pain in chest

• SOB

• Diaphoresis

MI S/S in FEMALE

• N/V

• Jaw, neck, or upper back pain

• Sometimes chest pain (but not always)

• SOB

• Diaphoresis

• Pressure or pain in lower chest or abd.

• Syncope

• Indigestion

• Extreme fatigue

What labs do we look at for an MI? What do each of these labs tell us?

ECG = fastest diagnostic tool *** obtain labs within first 10 min of report of chest pain!!! ***

Myoglobin = earliest marker of injury to cardiac or skeletal muscle (levels no longer evident after 24 hrs)

Creatine kinase-MB = peaks around 24 hrs after onset of CP (levels no longer evident after 3 days)

Troponin I or T = any positive value means damage to cardiac tissue & should be reported (levels no longer evident after 10 days)

What EKG changes happen with a NSTEMI?

ST depression or T-wave inversion

• important to note that changes in ECG along with elevation of troponin should always be assessed in conjunction with the clinical presentation and hx of the pt

NSTEMI - ST Depression

NSTEMI - T inversion

What EKG changes happen with a STEMI?

ST elevation = MI/necrosis

• A thrombus causes a 100% occlusion to the coronary artery; this is a medical emergency and requires immediate revascularization of the blocked coronary artery (usually via cardiac catheterization).

What are the interventions for STEMI and what are more of a priority?

• Percutaneous coronary intervention is the preferred reperfusion strategy in patients whose symptom onset was within the past 12 hours

• Give aspirin ASAP (325mg)

• Obtain the patient’s vital signs (BP, HR, RR) and continue to monitor these

• Administer supplemental oxygen if needed to maintain oxygen saturation greater than 90%

• Treat ongoing chest pain with sublingual nitroglycerin: IV nitrates may be used for persistent symptoms;  IV morphine may be given for severe discomfort

• Administer β-blocker, providing there are no contraindications, and statin

• Administer morphine for pain and anxiety

• Provide continuous ECG monitoring

What is a cardiac catheterization?

Procedure that examines how well the heart is working by opening the coronary artery using a balloon or placing a stent

Why would a pt need a cardiac catheterization?

• Clears blocked blood vessels via angioplasty

• Placing a stent in blood vessel to keep blocked artery open

• Implanting a pacemaker to stimulate the heart & normalize HR

• Apply heat or cold to heart tissue to correct an irregular HR (ablation/a-fib ablation)

What meds do we hold prior to a cardiac cath & why?

• Diuretics

• Warfarin & other PO anticoagulants

• Metformin

  • bc it can cause lactic acidosis if contrast dye affects kidneys

What are the complications to look out for when caring for a patient post-catheterization? 

• Cardiac dysrhythmias

• Hematoma

• Potassium levels

  • imbalances = dysrhythmias

• Assess peripheral pulses

  • to ensure they stay the same bilaterally

CABG

coronary artery bypass graft

What is CABG?

Restores blood flow to heart by bypassing blocked arteries

• often performed after a recent cardiac cath revealing 4-vessel disease

What is the procedure of CABG?

Extracts blood vessel from another area of body (commonly saphenous vein in leg) and attaching it to a part of the heart before the blockage, and then to another part after the blockage  

Post-Surgery CABG Potential Complications

• HF

• RF

• MI

• Arrythmias

• Stroke

• Pulmonary comp.

• Changes in condition

• Wound infect.

• Death

Post-Surgery CABG Medications

• Statins to control cholesterol  

• Antihypertensives to control BP 

• Antiplatelet therapies to prevent thrombus formation 

• Prevent occlusion of the graft 

• Aspirin 100-325mg/day initiated 6 hours after CABG and then continued forever  

• Clopidogrel and ticagrelor are administered for 1 year  

• BBs to reduce HR and BP, lower the workload of the heart, and to improve blood flow  

• Prophylactic abx during procedure and 48 hours after the procedure are administered to prevent sternal wound infection  

HVD

heart value disease

2 Types of HVD

• Stenosis

  • (narrowed opening impedes blood moving forward) 

• Regurgitation

  • (some blood flows backwards d/t valves not closing completely) 

Why is heart valve disease a concern?

Several conditions that prevent one or more of valves in the heart from working correctly

• may reduce blood flow & cause heart to work harder & eventually become life-threatening

What are the various causes? 

• Rheumatic fever from strep throat that wasn’t treated  

• Congenital defect  

• Decline/calcifications of valve tissue with loss of function over time  

• Heart failure 

• Endocarditis  

HVD S/S

• Fatigue

• Palpitations

• Edema

• Weakness/dizziness  

• Increased SOB (esp with physical activity)

• CP (esp with exertion) 

TAVR

transcatheter aortic value replacement

What is TAVR?

A minimally invasive procedure utilized to remove the damaged valve

What are the most commonly replaced heart valves?

• Aortic

• Mitral

Heart Valve Replacement Pt Education

• Lifelong anticoagulant therapy with warfarin is required if a mechanical valve was used 

  • To prevent thrombus formation 

• INR will need to be monitoring frequently (therapeutic rang is 3-4) 

  • Biological valves such as bovine or porcine valve can be used and does NOT require life-long anticoagulation  

  • Biological valves typically need to be replaced earlier than a mechanical valve  

P-wave

Arterial contraction

• Depolarization

PR-Interval

Movement of electrical activity from atria to ventricle

QRS Complex

Ventricular contraction

• Depolarization

ST-Segment

Time between ventricular depolarization & repolarization

T-Wave

Ventricles are relaxing

• Repolarization

TP-Interval

Ventricles are relaxing & filling

QT-Interval

Time it takes for ventricular depolarization (contraction) to repolarization (relaxation)

How do you estimate HR using a 6-second strip? 

count the # of QRS complexes and multiply by 10