Heart Failure
Nursing 308 with Blakely at Capital University
About this deck
By: SA Reid
Textbook:
Pharmacology for Nursing Care, 7th Edition (Book & CD-ROM)
Understanding Pathophysiology
Understanding Pharmacology: Essentials for Medication Safety
Created: 2012-03-12
Size: 83 flashcards
Views: 16
Textbook:
Pharmacology for Nursing Care, 7th Edition (Book & CD-ROM) Understanding Pathophysiology Understanding Pharmacology: Essentials for Medication SafetyCreated: 2012-03-12
Size: 83 flashcards
Views: 16
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Cardiac output:
Amt of blood pumped by the heart in one minute
What makes up CO?
HR x Stroke volume
What is normal CO for adults?
4-8L/minute
What determines stroke volume?
Preload
Afterload
Contractility
Afterload
Contractility
Stroke volume is:
Amt of blood pumped by the heart in a single beat
SVI:
Stroke volume index
What is normal stroke volume for adults and adolescents?
60-130 mL/beat
CI
Cardiac index
Cardiac index:
CO corrected for body size
What is normal adult/adolescent CI?
2.5-4.0 L/min/m2
What is normal infant/child CI?
3.5-4.5 L/min/m2
stroke volume
- the volume of blood ejected from a ventricle at each beat of the heart
- equal to the difference between the end-diastolic volume and the end-systolic volume.
How do you calculate CI?
CO/BSA (body surface area)
Chronotropy:
Factors that affect the HR
Chronotropy factors:
Vasomotor Center in medulla oblongata (brainstem)
- Cardioacceleratory (SNS, beta-1 receptors)
- Cardioinhibitory (PSNS)
Most factors that help INC CO also INC [blank]
Myocardial (heart muscle) oxygen demand
Local chronotropy factors:
Drugs
- Antiarrhythmias
- Anti-convulsants
- Some psych drugs
- Myocardial ischemia
- Electrolyte & Endocrine disorders
What are the benefits/disadvantages of INC HR:
Benefits
- INC CO/CI, blood flow and pressure, tissue perfusion
- DEC diastolic filling, DEC coronary artery perfusion, INC myocardial O2 demands
What drugs would you give to INC HR?
Epinephrine
Anti-choleragenic
Anti-choleragenic
What are the benefits/disadvantages of DEC HR:
Benefits
- DEC myocardial workload, DEC myocardial O2 demands
- DEC CO
Preload:
Amt of stretch in ventricle muscle just before systole (end of diastole)
Measured in end-diastolic pressure (reflects end-diastolic volume)
Measured in end-diastolic pressure (reflects end-diastolic volume)
Clinically how do you measure preload?
Right side heart
- CVP (central venous pressure)
- RAP (right atrial pressure) 0-8 mm/Hg
- PAW (pulmonary artery wedge pressure)
- LAP (left atrial pressure) 4-12 mm/Hg
What are the disadvantages of INC preload?
INC myocardial O2 consumption
INC risk for pulmonary edema
INC stroke volume, CO & tissue perfusionWhat are the disadvantages of INC preload?
INC risk for pulmonary edema
INC stroke volume, CO & tissue perfusionWhat are the disadvantages of INC preload?
What are the advantages/disadvantages of DEC preload?
Disadvantages
- DEC stroke volume, CO, tissue perfusion
- DEC myocardial O2 consumption
- Risk of pulmonary and peripheral edema
What clinical conditions & tx affect preload:
- Hypovolemia
- Hypervolemia
- Vasodilation (more change on afterload)
- Diuretics (DEC)
- Fluids
- Heart Failure (INC)
- Stenotic (stiff) or leaky valves (INC)
- Aortic or Mitral
Why would you want to DEC the HR of a HF pt?
DEC heart workload
Afterload
pressure that the ventricles must overcome to eject blood into arteries
The resistance to ejection (afterload) is affected by the....
- pressure in the aorta
- total peripheral resistance
- determined by the arteriole diameters
- pathological changes that lead to a narrowing (stenosis) of the aortic valve or an aorta itself
PVR
- Pulmonary Vascular Resistance
- Measures right ventricular afterload
SVR
- Systemic vascular resistance
- Measures left ventricular afterload
Why would you want to increase preload?
Helps increase stroke volume
What is the "Frank Starling Law Of The Heart"?
The greater the volume of blood entering the heart during diastole (end-diastolic volume), the greater the volume of blood ejected during systolic contraction (stroke volume) and vice-versa.
increases in EDV cause increases in SV
* intrinsic
* even if removed from body, still occurs
* no endocrine or nervous system influences
*** sympathetic nervous system activity can increase proportion of increase
What is the downside of Frank-Starling Law of the Heart?
To increase preload, you would increase fluids. If you increase the stroke volume above a certain point (Wedge pressure <18) you can put a pt in pulmonary edema. You can also stretch the heart b/c of increased volume/pressure.
Effects of INC afterload:
Benefits
- INC BP, INC tissue perfusion
- INC workload of heart, INC myocardial O2 consumption
- DEC ability of ventricles to eject, tissue perfusion & INC backup of fluid
Effects of DEC afterload:
Benefits
- DEC workload of the heart, myocardial O2 consumption
- DEC BP, tissue perfusion
How would you DEC preload? Why?
Diuretics
Tx for pulmonary edema
Tx for pulmonary edema
Conditions or tx that affect afterload:
- Vasodilators
- Aortic stenosis
- Vasoconstrictors (vasopressin)
- Pulmonic stenosis
- Lung disease
- Atherosclerosis
Contractility:
Force of myocardial contraction or the speed at which the myocardial fiber shortens
Effects of INC contractility:
Benefits
- INC stroke volume, CO, BP, tissue perfusion
- DEC myocardial workload & O2 consumption
Effects of DEC contractility:
Benefits
- DEC myocardial workload & O2 consumption
- DEC stroke volume, CO,BP, tissue perfusion
Conditions or tx that would affect contractility:
- MI
- Beta-adrenegic blockers
- Ca
- Digoxin
- Epinephrine/norepinephrine
- Ventricular dilation
Heart failure:
Failure of heart to pump blood to meet tissue requirements
- Inability to fill
- Inability to pump
- DEC in cardiac reserve
Congestive Heart Failure results in:
- Pulmonary edema - left heart failure
- Peripheral edema - right heart failure
Systolic HF decreases contractability. What happens to the heart?
- Decrease in SV
- Increase preload
- Heart diulates
- Increase in ventricular end diastolic volume
What happens in diastolic HF?
- Ventricular filling failure
- Ventricular hypertrophied (thicker)
Systolic heart failure pathophys:
- Weak ventricular muscle can not eject blood during systole
- Compensation: ventricular dilation
Diastolic HF pathophys:
- Ventricles stiff and unable to fill d/t smaller ventricular chamber & poor compliance
- Compensation: Ventricular hypertrophy
Dromotropy:
Increased speed of conduction
Inotropic:
Heart contractillity
What sounds would you expect to hear with diastolic heart failure?
Gallops
Second earliest sign of HF
Second earliest sign of HF
What is the first sign of HF?
HR increases and may have irregular rhythm
Causes of heart failure
- Abnormal volume (pushes blood into lungs, etc.)
- Abnormal pressure load (INC pulmonary pressure d/t COPD, etc; pulmonary & aortic stenosis, HTN, atherosclerosis)
- MI,ischemia,myopathy affect pumping ability
- Filling disorder: tricuspid or mitral stenosis
- INC metabolic demands: exercise, stress
Risk factors for HF:
- Age
- Sex
- HTN, LVH, DM
- MI
- Valvular heart disease
- Obesity
Conditions/habits that INC risk for HF:
- Chronic kidney disease
- Immune activation
- Sleep apnea
- Smoking
- Stress
- Dyslipidemia
What morphological factors predispose a pt to HF?
Marfan's syndrome
Tall & thin people
Tall & thin people
Effects of forward HF (not ejecting blood normally):
Left heart
- DEC cap refill
- Brain slows
- O2 DEC to all organs
- Confusion
- INC RR
- Blood gases would stink
- Dry lung sounds
- Pulmonary artery pressure low
Effects of backwards HF (blood backs up):
Left heart failure
- Pulmonary edema
- INC HR & dysrhythmias
- Peripheral edema
- Peripheral edema
Biventricular failure:
- Both ventricles are affected
- Usually d/t MI or cardiomyopathies
- Can be d/t left HF (most severe)
s/s of biventrical failure:
- Backwards effects of RV failure
- Forward effects of LV failure
- Forward effects of RV failure off-set
- Backward effects of LV failure - less pulmonary edema
How can you tell if biventricular failure is caused by left-sided HF as opposed to another cause?
DEC edema in the lungs for true biventricular failure
Biventricular failure
- Both ventricles affected
- Usually d/t MI or cardiomyopathies
s/s of biventricular failure:
- Backward effects of RV failure
- Forward effects of LV failure
- Forward effects of RV failure off-set backwards effects of LV failure - less pulmonary
- Forward effects of LV failure
- Forward effects of RV failure off-set backwards effects of LV failure - less pulmonary
What is the difference between left-sided heart failure and biventricular failure?
Left-sided: pulmonary edema
Biventricular: backwards and forwards effects cancel each other out
Biventricular: backwards and forwards effects cancel each other out
Etiology of biventricular failure
- Virus
- Cancer tx
- Cancer tx
The backwards effects of RV failure do what to the lungs?
Pull blood from them
The forward effects of left ventricular failure do what to the lungs?
Dump blood in them.
How does the body compensate for HF?
- SNS stimulation:
- Cardiac dilation: more volume, INC preload
- Myocardial hypertrophy:: stronger contractions, INC stroke volume
- Fluid retention and peripheral vasoconstriction: INC vol. of blood, INC perfusion pressure
- Increased tissue O2 extraction: INC tissue perfusion
How does dilation help compensate for HF?
The more you stretch your heart in diastole, the more it will pump out in systole.
If dilated it can hold more blood = more blood to pump in systole
If dilated it can hold more blood = more blood to pump in systole
Drug tx of HF:
DEC myocardial O2 demand
- DEC preload
- DEC afterload
- Pain & anxiety meds
DEC pulmonary & peripheral edema
- INC myocardial O2 supply
- INC cardiac contractility
- INC CO & tissue perfusion
- DEC preload
- DEC afterload
- Pain & anxiety meds
DEC pulmonary & peripheral edema
- INC myocardial O2 supply
- INC cardiac contractility
- INC CO & tissue perfusion
Human B-type Natriuretic Peptides (hBNP):
- Secreted by right atrium
- Potent vasodilator
- DEC preload & afterload
- INC CO
- Also used as a dx tool to ID left ventricular dysfunction
- Works the opposite as aldosterone: diuretic
- Potent vasodilator
- DEC preload & afterload
- INC CO
- Also used as a dx tool to ID left ventricular dysfunction
- Works the opposite as aldosterone: diuretic
Why would you give hBNP to a HF pt?
DEC edema
Watch for hypovolemia, dehydration, DEC tissue perfusion
Watch for hypovolemia, dehydration, DEC tissue perfusion
Diuretics f(x):
Get rid of excess fluid
Hypovolemia, dehydration, DEC tissue perfusion
Hypovolemia, dehydration, DEC tissue perfusion
Angiotensin receptor blockers & ACE inhibitors do what to the HF pt?
DEC aldosterone (anti-diuretic)
DEC preload & afterload
DEC myocardial workload
Hypotension & DEC tissue perfusion - side effect
DEC preload & afterload
DEC myocardial workload
Hypotension & DEC tissue perfusion - side effect
ACE inhibitors:
end in -pril
Prevents the activation of RASS by blocking conversion of Angiotensin I to II
Prevents the activation of RASS by blocking conversion of Angiotensin I to II
Cardiac glycosides - digoxin
- Check the apical rate b/c most HF pts in a-fib to a-flutter. Want to tx what is going on electrically in heart. May not appear in radial pulse.
- Toxicity: abnormal rhythms
- Blocks Na & K coming out of heart muscle to paralyze Na/K pump
- Narrow therapeutic window
- Toxicity: abnormal rhythms
- Blocks Na & K coming out of heart muscle to paralyze Na/K pump
- Narrow therapeutic window
digibind
antidote for digoxin
Phosphodiesterase inhibitors:
- End in -rinone
- Blocks intracellular phosphodiesterase which breaks down cAMP & ATP
- Blocks intracellular phosphodiesterase which breaks down cAMP & ATP
- INC contractility
- INC vasodilation
- INC bronchodilation
What are indication for Phosphodiesterase Inhibitors?
Only for short-term management of HF
when pt doesn't respond to digoxin or vasodialtors
Beta-1 Blocker
- DEC myocardial O2 demands
- DEC Chronotrophy, Dromotrophy, Inotrophy
- DEC lipolysis
- DEC Chronotrophy, Dromotrophy, Inotrophy
- DEC lipolysis
Beta-2 Blockers
- DEC bronchodilation and smooth muscle relaxion
- DEC SNS
- DEC renin release
- Vasoconstriction of coronary & skeletal blood vessels
- DEC blood sugar
Why should an MI pt always leave the hospital with a beta-blocker script?
DEC mortality
Lessens cardiac workload
Lessens cardiac workload
Side effects of Beta blockers
- Prolongs hypoglycemia
- Bradycardia
- Fatigue
- Prevents bronchioles from dilating- generally contraindicated in asthma and COPD patients
- Do not abruptly stop therapy!! Heart can become "super reactive" to sympathetic stimulation.
- Can exacerbate symptoms of peripheral vascular disease
About this deck
By: SA Reid
Textbook: Pharmacology for Nursing Care, 7th Edition (Book & CD-ROM)
Understanding Pathophysiology
Understanding Pharmacology: Essentials for Medication Safety
Created: 2012-03-12
Size: 83 flashcards
Views: 16
Textbook:
Pharmacology for Nursing Care, 7th Edition (Book & CD-ROM) Understanding Pathophysiology Understanding Pharmacology: Essentials for Medication SafetyCreated: 2012-03-12
Size: 83 flashcards
Views: 16
About StudyBlue
STUDYBLUE makes things that make you better at school.
Things like online flashcards with photos and audio.
Things like personalized quizzes and friendly reminders about when (and what) to study next.
Think of it as a digital backpack™: access to all of your study materials online and on your phone.
STUDYBLUE exists to make studying efficient and effective for every student, for free. Join us.
“Simply amazing. The flash cards are smooth, there are many different types of studying tools, and there is a great search engine. I praise you on the awesomeness.”
Dennis
Dennis