Cardiac Function, Heart Failure, & Circulatory Shock (Ch. 27)-- Term First

Question 1

Coronary Artery Disease (CAD)

Answer 1

Occlusion or stenosis of coronary arteries → Imbalance b/w coronary blood supply and myocardial O₂ & nutrient demand

d/t– Atherosclerosis (most common)

Question 2

Heart Failure Clinical Manifestations

Answer 2

• Fatigue & weakness
  
  • ⇣ CO
• Cognitive impairment
  
  • d/t ⇣ brain perfusion
    
    • Confusion
    • Memory loss
    • Restlessness
    • Anxiety
    • Insomnia
• Cachexia & malnutrition
  
  • Ascites & tissue wasting w/ end-stage HF
    
    • ⇣ food intake d/t depression, illness, GI congestion
• Sudden cardiac death
  
  • d/t ventricular tachycardia or fibrillation

Question 3

Constrictive Pericarditis Clinical Manifestations

Answer 3

• Ascites
  
  • Fluid w/i abdomen
• Lower extremity edema
• Dyspnea w/ exertion
• Fatigue

Question 4

Frank-Starling Mechanism

Answer 4

• ⇡ Preload = ⇡ SV
  
  • The further you stretch a rubberband, the harder it snaps back
• Inotropy (⇡ SANS)
  
  • ⇡ Contractility
    
    • Curve shifts up & L
• Failure
  
  • ⇣ Contractility
    
    • Curve shifts down & R

Question 5

Cardiomyopathies

Answer 5

Inappropriate ventricular hypertrophy or dilation

d/t– Genetics, Ischemia, MI (ventricular remodeling), Idiopathic

Question 6

Acute Pericarditis

Answer 6

Short-term pericardial inflammation

• < 2 weeks
• Infectious or non-infectious

Question 7

Contractility

Answer 7

Ability of myocardial tissue to contract

⇣ d/t– MI (most common), ⇣ O₂ supply

Question 8

MI Treatment (STEMI)

Answer 8

• Pharmacologic therapy
  
  • ASA (chewed)
    
    • ⇣ Platelet aggregation
  • Morphine
    
    • Pain
    • Vasodilation
  • Sublingual Nitroglycerin (MONA)
    
    • Vasodilation
• Supplemental O2
• Active STEMI (EKG verfied)
  
  • Percutaneous coronary intervention (PCI)– w/i 60 min.
    
    • Cath lab
  • Coronary artery bypass graft (CABG)
  • Fibrinolysis– w/i 30 min.
    
    • Tissue plasminogen activator (tPA)
      
      • “Clot buster”
    • If no cath lab

Question 9

Constrictive Pericarditis

Answer 9

Development of a constrictive membrane around the heart

• Scar tissue b/w visceral & parietal layers
• Fixed CO
  
  • Regardless of contractility

d/t– Chronic inflammation, Cardiac surgery

Infection & Removal of pericardial sac → Remodeling

Question 10

Pericardial Effusion

Answer 10

Accumulation of fluid in pericardial cavity → Cardiac tamponade

d/t– Inflammation or infection (CA, cardiac surgery, trauma…)

Treatment– Removal of fluid, Percardiocentesis (needle aspiration)

Question 11

Ejection Fraction (EF)

Answer 11

Proportion of blood pumped out of ventricle with each beat

Measured w/ echocardiogram

LVEF (%) = (SV/EDV)100

LVEF= Left ventricular ejection fraction (normal 55-75%)

SV= Stroke volume

EDV= End diastolic volume

Question 12

Shock Response

Answer 12

• Anaerobic metabolism
  
  • Lactic acid accumulation
  • ⇣ ATP → Na⁺/K⁺ ATPase pump failure
  • ⇡ Membrane permeability → Cell swells & bursts
• Compensatory mechanisms (Short-term)
  
  • ⇡ SANS
    
    • ⇡ HR
    • Vasoconstriction
  • ⇡ Renin
    
    • ⇡ Angiotensin II
      
      • Vasoconstriction
      • ⇡ Blood volume
    • ⇡ Aldosterone
      
      • ⇡ Blood volume

Question 13

Objective Evidence of Cardiogenic Systemic or Pulmonary Congestion

Answer 13

• Non-Invasive
  
  • Chest x-ray
    
    • Fluid congestion
      
      • White cotton candy-like appearance
  • Echocardiogram
    
    • Elevated filling pressures
• Invasive
  
  • R heart or pulmonary artery catheterization

Question 14

Myocardial Infarction

Answer 14

Prolonged ischemia causes irreversible damage to the heart muscle (myocyte necrosis)

• Myocyte injury → death
• Structural & functional changes of cardiomyocytes (permanent cells)
  
  • Adverse myocardial remodeling
    
    • Fibrosis of myocardium

Question 15

Natriuretic Peptides

Answer 15

Neurohumoral compensatory mechanism of HF

Diuresis & Natriuresis (⇡ GFR) → ⇣ Fluid volume → ⇣ Workload of the heart

Inhibit SANS, RAAS, ADH/Vasopressin, & CNS thirst/salt appetite signaling

• Atrial natriuretic peptide (ANP)
  
  • Released from atrium
    
    • d/t atrial stretch, pressure, or fluid overload
• B-type natriuretic peptide (BNP)
  
  • Released from ventricles
    
    • d/t increased ventricular pressure or fluid overload
    • Measured clinically

Question 16

Myocardial Infarction Types

Answer 16

The extent of necrosis determines EKG tracing differences

• STEMI
  
  • ST-segment elevation
    
    • Full necrosis of one area
      
      • Blocked conduction
    • “Tombstone” = MI
• Non-STEMI
  
  • Non-ST segment elevation
    
    • ST-segment depression
      
      • Partial necrosis
        
        • ⇣ Conduction
    • OR T inversion
  • May indicate ischemia
    
    • Does not always = MI

Question 17

Cardiac Catheterization

Answer 17

Assessment of coronary blood flow & perfusion

• Done under x-ray
• Invasive, sterile procedure
  
  • Catheter placed in femoral or brachial artery or vein
• Assess blood flow through the heart
• Angioplasty
  
  • Inflate balloon → Improved blood flow through arteries
• Stent
  
  • Metal mesh coil keeps arteries open
• Heart tissue biopsy
• Fractional flow reserve
  
  • Measurement of arterial blockage
• Intravascular ultrasound (IVUS)
  
  • Blood vessel lumen measurement

Question 18

Atherosclerosis

Answer 18

• Impaired contractility
• Deprivation of myocardial O₂ & nutrients
  
  • Mismatch b/w supply & demand
• Leads to CAD

Question 19

Types of Shock

Answer 19

• Hypovolemic
  
  • Acute blood loss (15% or more)
• Cardiogenic
  
  • Heart fails to pump sufficient amount of blood
• Distributive (Normovolemic)
  
  • Capacity of vascular compartment expands
    
    • Neurogenic
    • Anaphylactic
    • Septic

Question 20

Rheumatic Heart Disease Clinical Manifestations

Answer 20

• Mitral valve stenosis (narrowing)
• Rheumatic carditis
• Polyarthritis
  
  • Most common
• Skin lesions

Question 21

Myocardial Ischemia

Answer 21

Coronary blood flow doesn’t meet metabolic demands of heart

1st– Stable angina

2nd– Unstable angina → ACS

Prolonged– MI (STEMI or non-STEMI)

Question 22

Acute Coronary Syndrome

Answer 22

Sudden coronary obstruction d/t thrombosis formation b/c of an unstable lesion

d/t– Unstable angina, MI (STEMI or non-STEMI)

• Complications
  
  • Dysrhythmias
  • CHF
  • Sudden death

Question 23

Types of Heart Failure

Answer 23

• Can lead to each other
• Left ventricular failure
  
  • HFpEF
  • HFrEF
• Right ventricular failure
• Both ventricles fail

Question 24

Electrocardiogram

Answer 24

Assessment of coronary blood flow & perfusion

• Measure of electrical conduction through the heart
• Impacted by
  
  • Temperature
  • Stress
• Full
  
  • 12 leads
• Monitor
  
  • 3-5 leads

Question 25

Stroke Volume (mL/beat)

Answer 25

Volume ejected from ventricle **w/ each beat**

Question 26

Aortic Valve Disorders

Answer 26

* Stenosis * **⇡ Afterload → LV Hypertrophy** → HF * Regurgitation * **⇡ Preload → ⇡ Size/Dilation of LV → ⇡ SV** → HF

Question 27

Cardiogenic Shock

Answer 27

**Heart fails to pump** adequate amount of blood to **meet O₂ demands** d/t-- MI w/ LV failure * **⇣ CO** * Tissue hypoxia * **Normal vascular volume** * Compensatory mechanisms * **WORSEN** situation * ⇡ SANS * **⇡ HR** * **⇡ Preload** * ⇡ RAAS * **⇡ Blood volume** * ⇡ ADH/Vasopressin * **⇡ Blood volume**

Question 28

Acute Pericarditis Clinical Manifestations

Answer 28

* **Chest pain** * ⇡ w/ breathing, coughing, swallowing, & positional changes * ⇣ w/ sitting upright & leaning forward * **Pericardial friction rub** * **EKG changes** * ⇣ CRP * C-reactive protein * **⇣** ESR * Erythrocyte sedimentation rate Treatment-- NSAIDs, Antimicrobials

Question 29

Hypertrophic (Obstructive) Cardiomyopathy

Answer 29

Thickening of septal wall/**⇣ LV chamber size** → **⇣ Outflow from LV → ⇣** Compliance & **⇣ SV** **⇣** Ventricular relaxation & **⇣** Compliance → **Impaired diastole** * Most common inherited heart defect * **Autosomal dominant** * 1:500 * Cause of **sudden cardiac death in young athletes**

Question 30

Afterload

Answer 30

* **Force** * **LV must generate** to eject blood into aorta * **@ beginning of systole** * “Load” against which heart must pump * Determinants * **PVR** * ⇡ BP = ⇡ CO & ⇡ PVR * Increased w/ * **⇡ PVR** * **HTN**

Question 31

Complications of Shock

Answer 31

* Acute Lung Injury **(ALI)/**Acute Respiratory Distress Syndrome **(ARDS)** * Sudden onset of **profound dyspnea** * **Hypoxemia refractory to supplemental O₂** * Potentially fatal * Acute Kidney Injury **(AKI)** * **⇣ Renal perfusion** * Disseminated Intravascular Coagulation **(DIC)** * Multiple Organ Dysfunction Syndrome **(MODS)**

Question 32

Control of Coronary Blood Flow

Answer 32

Dysfunction = **Coronary Artery Disease** (CAD) * **Physical** factors * Aortic bp * **Systole** = Contraction/Pushing * Coronary arteries compress * **Diastole** = Relaxation/Filling * Perfusion of the heart * **Neural** factors * **SANS** * ⇡ Flow * **PANS** * **⇣** Flow * Changes in HR, contractility, & bp * **Myocardial metabolic** factors * Driven by **O₂ demands** * Protective factors * **Adenosine** * Vasodilation → ⇡ Blood flow * **Nitric oxide** * Vasodilation

Question 33

Circulatory Shock

Answer 33

**Acute failure of circulatory system** to supply **peripheral tissues and organs** with adequate blood supply **resulting in cellular hypoxia** * **⇣ O2 & Nutrients** * **⇡ Waste** * Impaired cellular metabolism * Aerobic → **Anaerobic** * Release of **inflammatory mediators**

Question 34

RAAS

Answer 34

* ⇡ Blood volume * ⇡ BP * ⇡ PVR * ⇡ Preload * ⇡ CO

Question 35

Multiple Organ Dysfunction System (MODS)

Answer 35

Life-threatening complication of shock Progressive **dysfunction of two or more organ systems** d/t-- **Uncontrolled inflammatory response** to severe injury/illness **(sepsis, trauma, burns, major surgery…)** * Manifestations * Dysfunction of-- * Respiratory organs * Liver * Kidneys * GI organs * Heart failure Interventions-- **Support affected organs**

Question 36

Sepsis

Answer 36

Known or suspected infection → **Overactivation of inflammatory response** * Systemic **inflammatory** response syndrome **S/S** * **Fever** * **Tachycardia** * **Leukocytosis** * **Altered mental status** * **Hyperglycemia** * SEVERE * **Organ dysfunction** * **Tissue hypoxia** * SHOCK * **Hypotension** * Even w/ fluid replacement * ⇡ Risk of mortality

Question 37

Infectious Endocarditis (IE)

Answer 37

Infection of the inner surface of the heart Microbial agents w/i **valves & endocardium** → **Vegetation** & destruction of cardiac tissue * High mortality rate * **Staphylococcal** infections * Most common * **Aortic & Mitral valves** * Most common * **Acute** * Rapid onset * **Normal heart valves** * **Sub-acute** * Evolves slowly over months * Underlying **valve abnormality** * Life-threatening d/t-- Dental or surgical procedures, Illicit IV drug use, Valve or congenital abnormalities (⇡ risk) Prevention-- **Prophylactic antibiotics** (w/ dental or surgical procedure)

Question 38

Myocardial Infarction

Answer 38

**Myocardial tissue necrosis** d/t impaired coronary blood flow Coronary occlusion → Necrosis in **10 seconds** w/o O₂

Question 39

Compensatory Mechanisms of the Heart

Answer 39

* **Frank-Starling mechanism** * SANS * RAAS * Natriuretic peptides * Myocardial hypertrophy → Remodeling

Question 40

Advanced Therapy in End-Stage HF

Answer 40

* Venricular assist device * **LVAD**/bi-VAD * Internal device * **Takes over work of LV** * ⇡ Survival rates * Bridge gap to transplant * High maintainence * Infection & blood clot risk * Heart transplantation * Survival rate * 85% after one year * 65% after 5 years * **Low donor availability**

Question 41

Echocardiogram

Answer 41

Measure of coronary blood flow & perfusion * Assessment of **structure & function of the heart** * **Ultrasound** * Valves * Septal movement & volume * Measurements

Question 42

Right Heart Failure Clinical Manifestations

Answer 42

**Systemic** circulatory pressures & **⇣ CO;** Inbility of RV to **provide adequate blood flow to pulmonary circulation** d/t-- L HF, **Pulmonary HTN** (hypoxic pulmonary disease) Right = Rest of the body **⇡ Peripheral** hydrostatic pressure → **Edema & Third spacing** * **JVD** * **Edema** * **Peripheral** * **Dependent** * **Hepatosplenomegaly** * GI distress * Anorexia * **Ascites** * **Weight gain**

Question 43

Types of Left Ventricular Heart Failure

Answer 43

* **Can and do coexist** * **HFpEF** * **Diastolic** failure * Dilation → **⇣ Preload** * Preserved ejection fraction * **LVEF \> 50%** * **HFrEF** * **Systolic** failure * **⇣ Contractility** * Reduced ejection fraction * **LVEF \< 40%**

Question 44

Cardiac Tamponade

Answer 44

Life-threatening **compression of the heart** d/t **accumulation of fluid** w/i pericardial sac * Inflammation & pressure * **Fluid displaces septum** * w/ inspiration * **⇡ Intracardiac pressure** * **⇣ LV filling** * **⇣ SV** * **⇣ CO** * **Pulsus paradoxus** * 10 mmHg + decrease in SBP w/ inspiration

Question 45

Rheumatic Heart Disease/Rheumatic Fever

Answer 45

Immune-mediated inflammatory response to group A **streptococcal pharyngitis** * Affects heart, skin, & connective tissue * Acute * Inflammation of **all 3 layers & valves** * Epicardium * Myocardium * Endocardium * **History of streptococcal infection** * Inflammatory lesions * Recurrent phase * Continued effects * Chronic phase * **Permanent deformity of valves** * **10+ years** after initial infection

Question 46

Factors Affecting Stroke Volume (SV)

Answer 46

* **Preload** * **Afterload** * **Contractility**

Question 47

Types of Cardiomyopathies

Answer 47

* **Dilated** * Congestive * **Hypertrophic** * Obstructive * Hypertensive (Valvular)

Question 48

Heart Failure with Preserved Ejection Fraction (HFpEF)

Answer 48

**Left Ventricular** Heart Failure d/t-- **HTN** (hypertrophy), **Myocardial Ischemia** (ventricular remodeling) * **Diastolic** failure * **LVEF \> 50%** (normal) * **⇣ LV Compliance →** Abnormal diastolic relaxation **→ Pulmonary edema** S/S-- Dyspnea w/ exertion, Fatigue Treatment-- None

Question 49

Neurogenic Shock

Answer 49

**Decreased SANS** control of blood vessel tone **Increased PANS** activity d/t-- **Neurologic** injury (**vasomotor center** defect-- brain stem injury or anesthesia; **sympathetic outflow** defect-- spinal cord injury) * **Massive vasodilation** * **⇣** Vascular tone

Question 50

Stable Angina

Answer 50

* **Predictable** **chest pain relieved** w/ rest & nitroglycerin * **Fixed** atherosclerotic plaque * Narrow/partially occluded vessel * @ Rest, supply = demand * **Exertion →** chest pain * Vasoconstriction → Mismatch b/w supply and demand

Question 51

Heart Failure with Reduced Ejection Fraction (HFrEF)

Answer 51

**Left Ventricular** Heart Failure d/t-- Damage to myocardial tissue **(MI, chronic HTN)** * **Systolic** failure * **LVEF \< 40%** * Dilation → ⇡ Preload → **⇣ Contractility** * Ventricular remodeling d/t-- * **⇡ SANS** * **⇡ RAAS** * **⇡ Inflammatory mediators**

Question 52

Mitral Valve Disorders

Answer 52

* Stenosis * Incomplete **opening of MV** during diastole → **LA distention/dilation** & Impaired LV filling → ⇡ **Pressure** w/i pulmonary venous system → **Pulmonary edema** * Regurgitation d/t MV prolapse * Incomplete **closure of MV → Backflow** into LA (systole) **→** LA distention/dilation & **⇣ LV SV** → LV Hypertrophy → **LV HF**

Question 53

Myocardial Infarction Clinical Manifestations

Answer 53

* **Zone of hypoxic injury** * May progress to necrosis or **return to normal** * **Zone of reversible ischemia** * May progress to necrosis or **return to normal** * **Sudden severe chest pain** * Can radiate to neck, jack, arm, or epigastric region * Sending of impending doom → death * SOB * Weakness * N/V * Diaphoresis Monitoring-- * **EKG** * Assess for rhythm changes * Continuous monitoring * Vitals * O₂ levels * Lab work * **Troponin I** * **Most specific** * Elevated 2-12 hrs. after damage * **Remains elevated 2-4 wks.** * Creatinine Phosphokinase-MB **(CPK-MB)** * **Not specific to the heart** * Elevates w/i 4-8 hrs. * **Peaks @ 24 hrs.**

Question 54

Heart Failure

Answer 54

Clinical syndrome d/t **structural or functional cardiac abnormality;** End result of many clinical disease states (no single S/S) Corroborated by: * **⇡ Natriuretic peptide levels** * and/or **Objective evidence of cardiogenic pulmonary or systemic congestion** **Ventricle** is either **too weak** (dilation) **or too stiff** (stenosis) to pump blood d/t-- **Ischemic heart disease** (post-MI) and/or **HTN** → **Hypertrophy** and/or **Dilation** Risk factors-- * Age * Obesity * DM * **Renal failure** * **Valvular heart disease** * **Cardiomyopathies** * **Congenital heart disease** * Myocarditis * Excessive alcohol intake

Question 55

Preload (End Diastolic Volume)

Answer 55

* Pressure/Volume * **@ end of diastole** * on **LV wall** prior to contraction * Determinants * **End systolic volume** * **Venous return** * Increases w/ * **⇣ Contractility** * **⇡ Plasma volume**

Question 56

Unstable Angina

Answer 56

* **Unpredictable chest pain unrelieved** w/ rest & nitroglycerin * Occurs @ rest & w/ exertion * **Ruptured** atherosclerotic plaque * **Reversible MI** * Forewarning * **Return of perfusion** before significant necrosis occurs * Transient episodes @ site of plaque damage * **Thrombotic vessel occlusion** * **Vasoconstriction**

Question 57

Valvular Heart Disease

Answer 57

Dysfunction **@ any valve → Heart Failure** (HF) * **Stenosis** * Narrowing/stiffness of valve * Impaired valvular opening * **⇡ Resistance** → ⇡ Myocardial work & ⇡ Heart chamber volume * **Incompetent/Regurgitant Valve** * “Floppy” * Impaired valvular closing * **Backflow** of blood

Question 58

Infectious Endocarditis Clinical Manifestations

Answer 58

* **S/S of systemic infection** * Fever * ⇡ WBCs * Chills * Diaphoresis * **Heart murmur**

Question 59

Hypovolemic Shock

Answer 59

**Acute loss of blood volume** (600-900 mLs) d/t-- **Hemorrhage, Burns** (⇣ plasma), **Loss of GI fluid** (N/V) * Compensation * **⇡ SANS** * **⇡ RAAS** * **⇡ ADH/Vasopressin** * Nursing interventions * **STOP** blood loss * **Replace** lost volume

Question 60

Hypertensive (Valvular) Hypertrophic Cardiomyopathy

Answer 60

**⇡ Afterload → Hypertrophy of myocytes** to compensate for ⇡ workload Diastolic dysfunction → Systolic dysfunction d/t-- **HTN, Aortic stenosis** (Narrowing of aortic opening)

Question 61

Disseminated Intravascular Coagulation (DIC)

Answer 61

Systemic Inflammatory Response System Microvascular damage that causes **clotting at all sites simultaneously** Inflammation → **Endothelial injury** → **Clotting process repeats** (steps 3-5) → All platelets & clotting factors used up → **Uncontrolled bleeding**

Question 62

Myocardial Oxygen Supply & Demand

Answer 62

Imbalance → **Ischemia, Angina, MI, or sudden death** * **Supply** * Determinants: * **Perfusion** of blood to capillaries * O₂-carrying capacity of blood * **Hgb levels** * **Demand** * **⇡ LV contractility** → ⇡ O₂ demand * Systole * **⇡ HR** → ⇡ O₂ demands & ⇣ Blood flow d/t ⇣ Filling time * **⇡ LV pressure** → ⇡ O₂ demand & Coronary artery pressure * **d/t ⇡ Preload** * Water balloon effect

Question 63

Cardiac Output (mL/min)

Answer 63

Amount of blood ejected in **one minute (4-6 L)** ## Footnote **CO = SV x HR**

Question 64

Left Heart Failure Clinical Manifestations

Answer 64

**Pulmonary** vascular congestion & **⇣ CO** Left = Lungs **⇡ Pulmonary** hydrostatic pressure → **Pulmonary edema & Dyspnea** * **Exertional dyspnea** * SOB w/ activity * **Orthopnea** * SOB while laying flat * **Paroxysmal nocturnal dyspnea** * Sudden SOB while sleeping * **Fatigue & weakness** * Especially w/ exertion * **Pulmonary edema** * Cough * **Crackles** * **Wheezes** * **Sputum** * Blood-tinged * **Frothy** * Tachypnea * Confusion * Tachycardia * Cyanosis * Restlessness

Question 65

Heart Failure Pharmacological Treatments

Answer 65

Goal: Control **compensatory mechanisms** * First-line HFrEF treatment * **Diuretics** * **⇣** Blood volume * **ACE-Is** * ⇣ RAAS * **Beta-Blockers** * **⇣** SANS

Question 66

Heart Failure Clinical Manifestation

Answer 66

* Dyspnea * **Orthopnea** * SOB when laying down * **Paroxysmal nocturnal dyspnea** * Wake up d/t SOB * ⇣ Exercise tolerance * Fatigue * Edema * **Bendopnea** * SOB w/ bending over * **JVD** * S3 (Third heart sound) * **Cardiomegaly** * **Hepatojugular reflex** * JVD w/ pressure on the liver

Question 67

Dilated (Congestive) Cardiomyopathy

Answer 67

**Dilated LV w/ thin walls** ("floppy") → **⇣ Contractility → ⇡ Preload** → Systolic dysfunction & **HF** d/t-- **DM, MI, Alcoholism, Hyperthyroidism**

Question 68

Anaphylactic Shock

Answer 68

Widespread **Type I Hypersensitivity** reaction → **Vasodilation & Hypovolemia** Treatment-- **Epinephrine →** Vasoconstriction, Bronchodilation, **⇡ CO** & Contractility, **⇣ Histamine** TOP PRIORITY: **Maintain airway**