Class 11 - Alterations in Cardiovascular Function, Heart

Question 1

Coronary Arteries

Answer 1

Travel along the epicardial surface and then branch into the myocardium, and then to the endocardium

Question 2

Angina Pathophysiology

Answer 2

Angina pectoris

• Chest pain due to the ischemia of myocardial cells
• Cells temporarily deprived of adequate blood supply

Causes:

• Anything that causes an imbalance between oxygen supply and demand
• Obstruction: vessel spasms, atherosclerosis (stable and unstable plaques)
• Hypotension, anemia, hypoxemia, systemic infection

Manifestations

• Chest pain, substernal
• Pressure, tightness, squeezing
• Radiating pain to neck, arm, jaw
• Referred pain due to pain pathways in the heart

Associated Manifestations

• Diaphoresis
• Dyspnea
• Pallor
• Nausea/vomiting

Question 3

Variant Agina

Answer 3

“Prinzmetal’s Angina”

• Vasospasm: no evidence of coronary artery disease, excess SNS, decreased vasodilators
• Pain is cyclical and often at night - linked to circadian rhythm
• Treated with calcium channel blocker medications

Question 4

Stable Angina

Answer 4

• Due to Atherosclerosis (stable plaques)
• Narrowing of the vessel lumen because of atherosclerosis, causes coronary artery disease
• Increase in oxygen demand can trigger chest pain
• Vessels can’t dilate to increase oxygen delivery
• Pain is predictable, relieved by rest or nitroglycerin

Risk Factors

• DDHS, dyslipidemia, diabetes, hypertension, smoking
• Men, age, African ethnicity, genetics

Management

• Reduce risk factors
• Nitroglycerin
• May require interventions to open up or bypass obstruction

Question 5

Unstable Angina

Answer 5

Athersclerosis (unstable complicated plaques)

• Coronary artery disease
• Plaque is prone to rupture
• Thrombus impedes blood flow
• Categorized into Acute Coronary Syndrome

Question 6

Myocardial Infarction

Answer 6

Heart attack

• Similar etiology to Unstable Angina - plaque is unstable/complicated and prone to rupture. Thrombus impedes blood flow
• Same as unstable angina, but longer. Causes cellular death and scar formation.

Manifestations:

• Prolonged angina (20-30 mins)
• Nausea
• Diaphoresis
• Pallor, cool, clammy
• Tachycardia
• Dyspnea
• Apprehension, feeling of doom
• More subtle in women

Diagnosis:

1. Physical assessment
2. Electrocardiogram for ECG changes
   - If the ST segment is elevated, a coronary artery is 100% block (MI-STEMI)
   - If the ST segment is not elevated, the artery is typically narrowed, but not 100% blocked
   - ST segment also helps to tell how much of the myocardial wall is dead
3. Cardiac biomarkers
   - Released from cells that have died
4. Troponin
5. Creatine Kinase - MB

Treatment:

• Primary prevention: risk factor reduction
• Secondary prevention: early detection
• Tertiary prevention: ASA/aspirin (decreases platelet stickiness), oxygen, nitroglycerin, morphine. Also coronary artery bypass surgery and fibrionlytic clot busters.

Complications

• Dysrhythmias
• Heart failure
• Cariogenic shock
• Rupture of heart tissues
• Sudden cardiac death

Question 7

Acute Coronary Syndrome

Answer 7

Caused by a plaque that is unstable/complicated and prone to rupture - thrombus is impeding blood flow

• Heart is hurting but still alive
• Unstable angina - ischemia is still reversible
• MI, 2 types. Ischemia is irreversible

Question 8

Left Heart Failure

Answer 8

• Also known as Congestive Heart Failure - CHF
• With reduced ejection fraction 55% is normal. 55 ml out of 100 ml in the heart being pumped out
• Due to the inability of the inability of the left ventricle to effectively push oxygenated blood forward into systemic circulation
• It becomes more distended as the blood is back flowed, causing pulmonary congestion

Manifestations:
Head
- LOC**
- Agitation, restlessness, confusion, coma
Hands/Feet
- Pale or cyanotic
- Weak pulse
- Numbness, cold, delay in capillary refile
Kidney
- Decreased urine outpute
Left Atrium
- Distended
Lungs
- Congestion in pulmonary capillaries causes increased hydrostatic pressure
- Pulmonary edema: crackles, frothy/pink tinged sputum
- Exertional dyspnea, fatigue 
Vitals
- Heart and breathing rate increase 

Compensatory Mechanisms

• Vasoconstriction, but will eventually become maladaptive
• RAAS, ADH, begins reabsorbing sodium water because it’s not getting enough blood. Will also become maladaptive

Treatment:

• “Unload” the heart with diuretics
• Decrease heart rate and blood pressure with ACE inhibitors and Beta blockers

Question 9

Right Heart Failure

Answer 9

Inability of the right ventricle to effectively push de-oxygenated blood forward into the pulmonary circulation

• Causes hypoxemia and a back up of blood into systemic veins
• Mismatch of ventilation and perfusion

Causes

• Left heart failure
• COPD
• Congenital heart defect

Manifestations

• Fatigue
• Distended jugular veins
• GI distress and anorexia or weight gain
• Edema
• Splenomegaly and hepatomegaly
• Tachycardia and tachypnea

Treatment:

• “Unload” the heart with diuretics
• Decrease heart rate and blood pressure with ACE inhibitors and Beta blockers

Question 10

Hypovolemic Shock

Answer 10

• Decreased circulation blood volume. Decreased BP and organ perfusion
• Loss of whole blood, plasma, or interstitial fluid

Signs and symptoms

• Decreased LOC
• Pale/cyanotic, decreased pulse, numbness, cool, decreased capillary refill in peripheries (hands and feet)
• Decreased urine output
• Increased heart rate
• Increased respiratory rate
• Decreased BP - hypotension
• Flat jugular veins

Question 11

Cardiogenic Shock

Answer 11

• Impaired contractility: decreased blood pressure, decreased organ perfusion
• Usually due to myocardial perfusion

Signs and Symptoms

• Decreased LOC
• Pale/cyanotic, decreased pulse, numbness, cool, decreased capillary refill in peripheries (hands and feet)
• Decreased urine output
• Increased heart rate
• Increased respiratory rate
• Decreased BP - hypotension
• Distended jugular veins

Question 12

Distributive Shock

Answer 12

Vasodilation occurs

• Decreased blood pressure, decreased organ perfusion.
• Warm, pink skin
• Bounding pulses
• They don’t look like they are in shock

3 types

1. Neurogenic
2. Anaphylactic
3. Septic

Question 13

Neurogenic Shock

Answer 13

• Spinal cord injury above the 6th thoracic vertebrae
• Loss of sympathetic tone in the arterioles, causes vasodilation

Signs and Symptoms

• Shock: hypotension, bradycardia, tachypnea, altered LOC.
• Distributive shock: warm, pink skin, bounding pulses.

Question 14

Anaphylactic Shock

Answer 14

• Widespread hypersensitivity reaction

Signs and Symptoms

• Shock: hypotension, tachycardia, tachypnea. and altered LOC
• Distributive: warm, pink skin and bounding pulses
• Anaphylactic: wheezing, stridor, edema and hives

Question 15

Septic Shock

Answer 15

• Systemic reaction to infection (bacteria, virus, fungi)

Signs and Symptoms

• Shock: hypotension, tachycardia, tachypnea. and altered LOC
• Distributive: warm, pink skin and bounding pulses
• Signs of infection: fever, WBC