Circulation & Perfusion Flashcards
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Is how the blood flows to a capillary membrane to provide nutrients and oxygen that the tissues and organs need
Perfusion
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Is the flow of blood throughout the heart and vessels
Circulation
Anatomy of the Heart
* Heart
- Muscle encased by ___
- 4 chambers
- 2 atria
- 2 ventricles
pericardium
The Heart
Is a muscle encased by the pericardium which is a sack of connective tissue and it’s located inside the chest cavity
Made up of 4 chambers
2 atria : ___ -walled that receive blood into the heart
2 ventricles : ___-walled that pump blood out of the heart
thin-
thick-
Valves are located between the heart chambers, and they open to allow blood to flow easily and without turbulence from one chamber to another AND they close tightly to prevent backflow of the blood or regurgitation
Base of the heart houses the atria and faces upward whereas the apex of the heart or the tip of the heart houses the ventricles and faces downward
Deoxygenated blood from organs and tissues flows through the venous system (superior and inferior vena cava) into the __ side of the heart and then into the pulmonary arteries and lungs
External gas exchange occurs at the ___-___ membrane
Oxygenated blood then flows from the lungs through the pulmonary veins into the ___ side of the heart and out into the arterial circulation through the ___
right
alveolar-capillary
left / AORTA
The Cardiac Cycle
Cardiac Cycle
* Contraction of atria
* Followed by contraction of ventricles
The Cardiac Cycle
Electrical Conduction
* Sinoatrial node (SA node)
> Pacemaker
> 60-100 beats/min
* Atrioventricular node (AV node)
* Bundle of HIS
* Right and left bundle branches
* Up the Purkinje fibers
Cardiac cycle
Includes the contraction of the 2 atria followed by contraction of the ventricles
The electrical activity of the ___ regulates the cardiac cycle
myocardium
Electrical conduction
The heart has areas of specialized nerve tissues that initiate electrical impulses without external nervous system stimulation
? - is the pacemaker of the heart and it is located in the right atrium; is going to initiate an impulse that triggers each heartbeat
Impulse travels rapidly down atrial conduction system and both atria contract as a unit
The ___ node receives that impulse - delays it for a second - and then sends that impulse into the right and left bundle of HIS and into the Purkinje fibers to the ventricles and lead to the contraction of the ventricles
sinoatrial node
atrioventricular
Electrical conduction cont’d
If there are any defects in this electrical system - impulses are going to travel more slowly or in some areas may even be blocked and this will lead to ineffective heart pumping and a decrease in cardiac output
The ___ node is in charge and initiates a rate of 60-100 bpm
If this node fails, then the atrioventricular node takes over the impulse but at a slower rate
If both of these nodes fail, the conduction fibers in the myocardium can initiate impulses - ___ conduction is at a very slow rate, usually less than 40 bpm
SA
ventricular
Systemic & Pulmonary Blood Vessels
All vessels - lined smooth endothelial layer
* Promotes nonturbulent blood flow
* Prevents platelets from sticking to walls & clotting
Arteries
* Thick elastic - allow for stretch & recoil
Arterioles
* Thinner walls
Systemic & Pulmonary Blood Vessels
Capillaries
* Connect arterioles with venules
* One cell thick allowing for gas exchange
Venules
* Thinner walls
Veins
* Thinner muscular walls, inelastic & collapse easily
Vascular system is composed of 3 types of vessels: ___, ___, and ___
All vessels are lined with smooth endothelial layer that promotes nonturbulent blood flow and prevents platelets from sticking to the sides of the walls and clotting
arteries, veins, capillaries
?
Have thick, elastic walls that allow them to stretch during muscle contraction = systole and to recoil when the heart relaxes = diastole
Arteries
?
Are smaller branches of the arteries made up of smooth muscle and thinner walls - they are controlled by the sympathetic nervous system (SNS)
Arterioles
?
Are microscopic vessels - connect the arterial and venous systems and carry blood from arterioles to venules - they are only one cell thick and this is why gas exchange is facilitated along with nutrients and waste between tissue cells and the blood
The venous system returns ___ blood to the heart
Capillaries
deoxygenated
___ and ___ have thinner muscular, inelastic walls that collapse easily - the walls contract or relax in response to feedback from the SNS
So when the blood volume is low, ___ contract to provide a smaller space for smaller volume of blood - when the blood volume is high, ___ are going to relax and enlarge to accomodate the increased volume of blood
veins; venules
veins x2
Coronary Arteries
* Supply blood to heart muscle
* Right coronary artery
* Left coronary artery
- Left circumflex artery
- Left anterior descending artery
Transport of O2 & CO2
* Adequate circulation & effective cardiovascular function regulation
- Circulate oxygenated blood to tissues and deoxygenated blood to lungs
- Hemoglobin reservoir for O2
- CO2 as product of aerobic tissue metabolism
In order to maintain or circulate oxygenated blood to organs and tissues and return deoxygenated blood to the lungs – blood flow – requires adequate circulation and effective regulation of the cardiovascular function
Hemoglobin is a reservoir for oxygen
97% of blood oxygen is bound to hemoglobin at the tissue level
Oxygen leaves hemoglobin and becomes dissolved in the blood and passes through the capillary membrane into the tissues
CO2 is a waste product of normal aerobic tissue metabolism
CO2 defuses through cellular & alveolar capillary membranes only in its dissolved state
CO2 can be carried in the blood; dissolved in the plasma (7%), attached to hemoglobin (23%), or converted into bicarbonate ions (70%)
Cardiovascular Function Regulation
* Autonomic Nervous Center (ANS)
Regulates cardiac function by:
- Cardiac rate
- Cardiac muscle contractility
- Vascular tone
* Heart
___ fibers - heart beats faster and contracts stronger
___ fibers - slow heart rate (no effect on contractility)
* Vascular system
- Sympathetic control
> Maintains partial state of contraction
> Constrict or dilate vessels in response to body needs
Sympathetic
Parasympathetic
Brainstem Centers
___
> Sense low pressure - brainstem centers stimulate sympathetic nervous system to increase heart rate & induce vasoconstriction
> Located in walls of heart and blood vessels; sensitive to pressure changes
___
> Main function to regulate ventilation
> Located in aortic arch and are sensitive to changes in blood, pH, O2 & CO2 levels
Baroreceptors
Chemoreceptors
Vascular System
- Sympathetic control maintains the blood vessels in a constant baseline state of partial contraction tone which allows a stable blood pressure and blood flow at rest or when a patient is sleeping
- Sympathetic stimulation above and beyond baseline tone varies in response to body needs
- So when there’s increased sympathetic stimulation it leads to constriction of vessels
e.g.
The skin, GI tract, and kidneys and dilation of other vessels like skeletal muscle - shunts blood flow to the skeletal muscle for a fight-or-flight response
Brainstem centers
The ___ center controls sympathetic stimulation of heart and vascular system
The ___ center controls parasympathetic slowing of the heart rate
vasomotor
cardioinhibitory
Factors That Influence Cardiovascular Function
Developmental Stage
* Young & middle adults
- Poor nutrition (too busy to prepare or eat high fat, high sugar foods)
- Lack of exercise
- Substance abuse (especially tobacco)
- Family history (of CVD)
* Older adults
- Efficiency gradually declines
> Loss of contractile strength
> Valves become thicker & rigid
> Peripheral vessels become less elastic - creates more resistance
- More prone to orthostatic hypotension
Heart becomes less able to respond to increased oxygen demands
Factors That Influence Cardiovascular Function
Stress
* Release of catecholamines (from SNS) = increased HR, contractility, vasocontriction, ↑ blood clots
Allergic reactions & air quality
* Allergic reactions include release of HISTAMINE & PROTEASE
> Vasodilation - ↑ blood flow, ↑ capillary permeability, more fluid leakage
Altitude
* Increase altitude - drop in O2 pressure - affects alveoli and tissue
Heat & cold
* Heat
> Vasodilation - ↑ cardiac output and oxygenation
> Increases metabolism (people sedentary in hot weather)
* Cold
> Vasocontriction and slow HR, metabolism
> Prolonged exposure leads to frostbite, loss of hypothalamic temperature regulation, and eventually death
Factors That Influence Cardiovascular Function
Lifestyle
Pregnancy
* ↑ demands (on O2, maternal metabolism, volume, iron requirements)
Nutrition
* Balance of proteins, carbs, fats, & nutrients
* Low-fat, low cholesterol, low sodium diet = heart healthy diet
* DASH diet - dietary approaches to stop HTN
* Especially iron and protein are important to prevent anemia which reduces blood O2 carrying capacity
* Green tea consumption has been associated with reduced mortality d/t CVD
Obesity
* Atherosclerosis & HTN = increase workload of heart
Exercise
* Improves circulation & oxygenation
* Regular aerobic exercise strengthens heart muscles - as heart becomes stronger, it becomes more efficient pump
Tobacco use
* Risk of coronary artery disease is 4x higher in cigarette smokers than non-smokers cigarette smoking
Substance abuse
* Depression of respiratory, cardiac, vasomotor centers in brain
?
Is a fatty buildup in the arteries that leads to HTN and decreased HDL (the good cholesterol)
Atherosclerosis
Factors That Influence Cardiovascular Function - Lifestyle
- DASH diet - Dietary approaches to stop HTN
- Based on a 2000-kilocalorie diet
* Grains 6-8 daily servings (whole wheat bread, cereal, oatmeal)
* Vegetables 4-5 daily servings (tomatoes, broccoli, carrots, peas, kale, spinach, beans)
* Fruits 4-5 daily servings (bananas, strawberries, oranges, prunes, raisins)
* Low-fat or nonfat dairy foods 2-3 daily servings (skim or 1% milk, low-fat cheese, low-fat yogurt)
* Meats, poultry, & fish 6 or fewer servings (lean meat, broil/roast, remove skin)
* Nuts, seeds, & legumes 4-5 servings per week
* Fats & oils 2-3 servings per day
Factors That Influence Cardiovascular Function - Medications
* Improve cardiac output and tissue oxygenation
* Slow HR or reduce the force of myocardial contraction
* Ease the workload of the heart
* Dilate blood vessels & reduce blood pressure in pulmonary & systemic circulation
* Remove excess fluid accumulation
* Block abnormal heart rhythms
___ regimen helps prevent cardiovascular disease (CVD)
> Blocks prostaglandins (substances that activate the formation of blood clots, signal injuries, & trigger pain)
- Reduction of risk of heart attack or stroke
> Recommended dose
- Adults over 50 who have a risk of CVD - 1 baby ASA 81 mg per day
Aspirin
Medications that PROMOTE Circulation
* Vasodilators (angiotensin-converting enzyme (ACE) inhibitors, angiotension II receptor blockers (ARBs), nitrates)
* Beta-adrenergic blockers
* Calcium-channel blockers
* Positive inotropic agents (cardiac glycosides [Digoxin])
* Diuretics (thiazide diuretics (HCTZ), loop-diuretics (furosemide), potassium-sparing diuretics (spironolactone)
Factors That Influence Cardiovascular Function - Pathophysiological Conditions
Cardiovascular Abnormalities
* Structure, function, & regulation
* Heart failure
* Cardiomyopathies
* Cardiac ischemia
* Coronary artery disease
* Dysrhythmias
* Valve abnormalities
* Peripheral vascular abnormalities
* Oxygen transport abnormalities
Cardiovascular abnormalities results from problems that occur with structure, function, and regulation of the cardiovascular system & they’re going to interfere with the flow of oxygenated blood to organs & tissues
Major abnormalities include heart failure (HF) which leads to an ineffective pump; includes right-sided HF, left-sided HF, or both right and left-sided HF
?
Has to do with the heart muscle; a disorder that leads to an enlargement of the heart & impaired cardiac contractility
___ if it results from a genetic disorder
___ if it results from another cardiovascular disease
Cardiomyopathy
Primary
Secondary
___ occurs when oxygen requirements of the heart are not met so prolonged ___ can lead to myocardial infarction where parts of the heart muscle start to die from lack of O2
Cardiac ischemia; ischemia
?
Is the transient chest pain (CP) d/t MI wherein tissue becomes injured but doesn’t necrose
Angina pectoris
___ is ischemic CP that has worsened in frequency, severity, or duration & if it is not relieved by usual measures & left untreated, can lead to MI
Unstable angina
___ is a predictable pattern of ischemic chest pain that is precipitated by known triggers like activity, large meals, temperature extremes, cigarette smoking, stimulants, sexual activity, strong emotions, & circadian rhythm patterns
Usually alleviated by rest & medications
Stable angina
Heart valve abnormalities create turbulent flow leading to a decrease in cardiac output & compromise tissue oxygenation = heard as a murmur = most common ones affect ___ & ___ valves
valve ___ is a narrowing = blood flows through a constricted opening in order to pump blood flow through that narrow valve; leads to increased workload of the heart & hypertrophy of the chamber that precedes that stenotic valve
valve ___ (insufficiency) - refers to the incomplete closure of the valve which leads to regurgitation of the blood back into the chamber from where it came - regurgitation leads to extended, increased workload of the chamber ejecting the blood
mitral; aortic
stenosis
incompetence
Peripheral vascular abnormalities have to do with impaired blood flow to & from organs & tissues
___ abnormalities disrupt blood return to the heart & S/S would be edema, brown skin discoloration, & tissue dysfunction r/t stasis ulcers
___ abnormalities disrupt flow of oxygenated blood to the tissues & S/S would be pallor, pain, weak or absent pulses, poor capillary refill, cool skin, & tissue dysfunction
venous
arterial
Oxygen transport abnormalities - ___ which is abnormal low levels of red blood cells, hemoglobin, CO when CO is inhaled, it binds tightly to hemoglobin actually at the O2 receptor sites making it impossible for hemoglobin to carry O2
anemia
Types of Cardiomyopathy
Normal Heart vs Mitral Valve Stenosis
Mitral Regurgitation
PAD vs. PVD: Test Tips & Memory Tricks (Video)
Nursing Process: Assessment
Assess Risk Factors
Anxiety
Physical Examination
* Weight, height, waist circumference
* Inspection
- Signs of distress (i.e. CP)
- Skin & mucuous membranes (signs of DVT; dyspnea)
* Palpation
- Pulses, skin temp, edema, tenderness
* Auscultation
- Heart sounds, vascular sounds, BP, LS (i.e. rales may signify ↓ cardiac output)
* Assess pain (location/duration/frequency/radiation); typically doesn’t change with inhalation & exhalation
Assess for fatigue = is subjective; a common sx of oxygenation prolems including pt’s who have anemia or HF; scale 0-10
Weak pulses, cool feet, lack of hair, & shiny skin on lower legs & feet usually are r/t PVD
Skin ulcers can be seen w/severe venous or arterial disease
Edema of feet & ankles can indicate HF
Assess for clot in veins (DVT) & signs = pain, warmth, redness & swelling of the leg
Nursing Process: Diagnostic Testing
* Blood oxygenation
- Oximetry, capnography, ABG’s
* Lab tests
- Cholesterol, lipid panel, c-reactive, blood glucose
* Cardiac monitoring
- Continuous ECG (3-5 electrodes placed on skin of chest)
- Resting ECG (uses 12 leads for 12 views of the heart)
Lipid panel
- Testing for total cholesterol, HDL, LDL, & triglycerides is recommended every 5 yrs for adults over the age of 20
- For adults, total cholesterol >200 mg/dL
C-reactive protein (CRP)
- Appears to be the most reliable marker for arterial inflammation
* Purpose of cardiac monitoring is to identify the pt’s baseline rhythm & rate; recognize significant changes in the baseline rhythm & rate in recognizing life-threatening arrhythmias that require immediate intervention
APE To Man
Aortic, Pulmonic, Erbs Point, Tricuspid, Mitral
These locations are optimal for listening to the 4 valves of the heart. Erb’s point is the best location listen for S2. At each location you should listen for any murmur for the associated valve.
Nursing Process: Diagnostic Testing cont’d
Cardiac Cycle - ECG
P wave
- Atrial depolarization - contraction
QRS complex
- Ventricular depolarization - contraction
Nursing Process: Diagnostic Testing cont’d
Cardiac Cycle - ECG
T wave
- Ventricular repolarization - relaxation
U wave
- r/t electrolyte imbalance
- r/t medications - Digitalis
- Inverted U can be r/t ischemia of cardiac muscle
Nursing Process: Diagnostic Testing cont’d
Cardiac Rhythms
* Dysrhythmias
- Heart rate/rhythm
> tachy-dysrhythmias
> brady-dysrhythmias
> ectopy
Nursing Process: Diagnostic Testing cont’d
Cardiac Rhythms
* Site of origin
> Supraventricular
> Junctional
> Ventricular
All dysrhythmias can lead to decreased cardiac output resulting in hypotension & tissue hypoxia
?
___ wave represents the firing of the SA node and the conduction of the impulse through the atria leading to atrial contraction or ATRIAL DEPOLARIZATION
P (wave)
?
The ___ represents VENTRICULAR DEPOLARIZATION and leads to ventricular contraction
QRS complex
?
The ___ wave represents the return of the ventricles to a relaxed state or resting state so that they can again be stimulated in; this is VENTRICULAR REPOLARIZATION
T (wave)
?
The ___ wave is not always seen but if seen it can be r/t an electrolyte imbalance like a hypokalemia or hypercalcemia or in response to certain medications like digitalis or epinephrine
An inverted ___ wave may occur w/ischemia to cardiac muscle
U (wave)
Dysrhythmias or abnormal heart rhythms
They are categorized as ____ if rates are above 100 bpm
___ if rates are less than 60 bpm
or ___, extra beats
tachy-dysrhythmias
brady-dysrhythmias
ectopy
They can also be classified by their site of origin
___ if they occur above the ventricles
___ if they occur within the AV node
or ___ if they occur in the ventricles
Supraventricular
Junctional
ventricular
Nursing Process - Analysis/Nursing Diagnosis
- Decreased cardiac output
- Risk for impaired cardiac tissue perfusion
- Risk for impaired cerebral, gastrointestinal, or renal tissue profusion
- Impaired peripheral tissue perfusion
- Risk for shock
- Activity intolerance risk acute pain
- Anxiety
Nursing Process - Planning Outcomes
- No dyspnea or shortness of breath
- Heart rate in expected range 60-100 bpm
- Peripheral pulse is strong and equally bilaterally
- Brisk capillary refill less than 2 seconds
Nursing Process - Planning Interventions/Implementation
* Manage anxiety
- Anxiety activates sympathetic nervous system (SNS) & triggers stress response ⇒ hormone changes HR & force of contraction; vessels constrict, blood clots easier
- Hormone changes including release of aldosterone that’s going to lead to fluid retention & increases BP
! Anxiety reduction is a priority intervention
Nursing Process - Planning Interventions/Implementation
* Promote circulation both venous & arterial
- Promote venous return & prevent clot formation
Adequate circulation ensures that oxygenated blood gets to the tissues & organs and venous blood returns to the heart
Promote venous return (meaning that blood returns from all the areas of the body up through the vena cava (superior & inferior vena cava) and into the right side of the heart)
- Elevate legs (above level of heart as gravity helps w/venous return)
- Do not cross legs
- Early & frequent ambulation (contraction of legs moves blood upward)
- ROM exercises
- Antiembolism stockings
- Sequential compression devices (aka pneumatic compression devices; inflate & deflate to promote venous return)
* Promote peripheral arterial circulation
- Smoking cessation
- Foot care
- Comfortable fitting shoes
- Regular exercise
- Proper leg positioning
- Medication (NEVER apply direct heat)
- Warmth; AVOID cold
- Graft bypass surgery/angioplasty
Arterial disease is usually found in the legs & feet and it occurs when tissues do not receive enough blood flow to keep up with the demand of O2
May be caused by build-up of fatty tissues or plaque within the arteries OR ATHEROSCLEROSIS
?
Pain with exercise - when arteries that supply blood in the legs are narrowed, leg pain occurs because of the lack of O2; this is called ___
intermittent claudication
?
Warmth leads to ___ AND ALSO prevents long periods of exposure to cold
Never apply direct heat to a limb b/c it increases the risk of burns
___ or angioplasty is the introduction of a mesh stent to create a path for blood to flow around the damaged area
vasodilation
graft bypass surgery
Arterial vs. Venous
Arterial
Cool to touch
Thin, dry/scaly skin
Hairless
Thick toenails
“Dr. EP”
Dangle legs = Rubor (flushing)
Elevate legs = Pale
Arterial vs. Venous
Venous
Warm to touch
Thick, tough skin
Brownish color
Prevent Clot Formation
- Reposition frequently
- Sterile technique with IV therapy
- Dilute IV medications properly
- Hydration
- Smoking cessation
- Medications
?
A ___ is a clot that travels in the bloodstream
A ___ is a stationary clot that adheres to the inside wall of the vessel; these can form after injury to the vessel or in response to hypercoagulability
embolus
thrombus
Administer Cardiovascular Medications - Drugs That Affect Blood Pressure
Antihypertensive Medications
- Angiotensin converting enzyme inhibitors (ACE inhibitors)
- Angiotensin II receptor blockers (ARBs)
- Calcium channel blockers
- Vasodilators
- Diuretics
- SNS drugs → beta-blockers
Antihypotensive Medications
- Sympathetic adrenergic agonists or vasopressors → epinephrine
ACE Inhibitors
- “PRILs” - Benazepril, Captopril, Enalapril, Lisinopril, Prinivil
- Prevent conversion of angiotensin I into angiotensin II - vasoconstrictor & stimulator of aldosterone release
- Leads to ↓ BP, ↑ serum K, and ↓ serum Na
- Used to treat HTN & HF
- Oral
- Metabolized in liver & excreted in urine & feces
- Adverse effects;
> Tachycardia, CP, HF, arrhythmias, GI ulcers, constipation, liver injury, renal insufficiency, renal failure, proteinuria, rash, alopecia, dermatitis, photosensitivity
> Unrelenting nonproductive cough possibly from effects on the lungs
Monitor Na & K levels
Angiotensin II receptor blockers (ARBs)
- “SARTANS” - Losartan, valsartan
- Bind with angiotensin II receptors & block vasoconstriction and the release of aldosterone = lower BP
- Used to treat HTN & HF
- Can be given orally
- Well-absorbed & metabolized in the liver, excreted in the feces & urine
- Adverse effects;
> Headache, dizziness, syncope, weakness, diarrhea, abdominal pain, nausea, dry mouth, tooth pain, cough, rash, dry skin, & alopecia
Calcium Channel Blockers
- ↓ BP, cardiac workload, & myocardial O2 consumption - affect cardiac workload
- Used to treat angina & HTN
- Immediate release
> Amlodipine (Norvasc) & nicardipine (Cardene)
- Sustained release or extended-release
> Diltiazem (cardizem CD), nifedipine (procardia XL), verapamil (calan SR)
- Orally
- Well absorbed, metabolized in the liver, excreted in urine, crosses placenta & enters breast milk
- Adverse effects - dizziness, lightheadedness, HA, fatigue, N/V, change in taste perception, hypotension, bradycardia, peripheral edema, heart block, skin flushing, rash & mouth sores
- Calcium channel blockers interact with grapefruit juice - increase medication toxicity
Calcium Channel Blockers - Therapeutic Action
Calcium channel blockers inhibit the movement of calcium ions across the membranes of the myocardial & arterial muscle cells, altering the action potential in blocking muscle cell contraction
This is going to lead to a depression of the myocardial contractility, slowing down of cardiac impulse formation in the conductive tissues, & relaxes & dilates arteries, causing drop in BP & decreases in venous return
Calcium Channel Blockers
Very Nice Drugs
Verapamil, Nifedipine, Diltiazem
Vasodilators
- Severe HTN, malignant HTN, or hypertensive emergencies
- Hydralazine & nitroprusside (nitropress)
- Vasodilation & drop in BP
- Nitroprusside - IV
- Hydralazine - oral, IV, IM
- Metabolized in the liver, excreted in the urine, crosses the placenta & enters breast milk
- Adverse effects - dizziness, anxiety, HA, reflex tachycardia, HF, CP, edema, skin rash, lesions, abnormal hair growth, N/V
- Cyanide toxicity may occur w/nitroprusside: dyspnea, HA, vomiting, dizziness, ataxia, LOC, imperceptible pulse, absent reflexes, dilated pupils, pink color, distant heart sounds, shallow breathing
Diuretics
- Increases excretion of sodium & water from the kidney
- Treatment for HTN often used to treat mild HTN
- Monitor serum sodium levels and blood volume
- Thiazide or thiazide-like diuretics are considered the first line medications to treat HTN
> Thiazide & thiazide-like diuretics include: chlorothiazide (Diuril), hydrochlorothiazide (HydroDiuril)
- Potassium-sparing - amiloride (Midamar), spironolactone (Aldacterone), triamterene (Dyrenium)
Beta-Adrenergic Agents : Beta-Blockers
- “LOL” Atenolol, metoprolol, propanolol
- Block vasoconstriction, decrease HR, decrease cardiac contraction, increase blood flow to kidneys
- Control HTN
- Monitor HR & BP prior to administration
Medications Used to Treat Heart Failure - Positive Inotropes or cardiac glycosides
- Digoxin (lanoxin)
> Increase force of contraction - slows HR - decreases conduction velocity through AV nodes
Oral : onset 30-120 min / IV : onset 5-30 min
Excreted in urine - monitor renal function
Adverse effects - HA, weakness, drowsiness, vision changes - a yellow halo around objects, GI upset & anorexia
Digit toxicity - anorexia, n/v, malaise, depression, irregular heart rhythms
Digoxin antidote - digoxin immune fab rapidly treats digoxin toxicity
- Interactions ⇒ Quinidine, erythromycin, tetracycline, cyclosporin, amiodarone, & verapamil may increase therapeutic effect
- Thyroid hormones, metoclopramide, St. John’s wort, psyllium may lead to reduced effects
- Oral digoxin may not be absorbed when taken with antacids, bleomycin, or methotrexate - do not take at same time but 2-4 hrs apart
- Monitor AP for one full minute before administering
> Hold the dose if the pulse is less than 60bpm in an adult (or < 90bpm infants)
> Check dose carefully
- Avoid administering the oral drug w/food or antacids to avoid delaying absorption
- Give small frequent meals; if given IV administer over 5 minutes
- Serum digoxin levels should be between 0.5-2 ng/mL
Medications Used to Treat Angina - Nitrates
- Isosorbide denitrate (isordil), nitroglycerin (nitrobid, nitrostat)
- Nitrates relax & dilate veins, arteries, & capillaries allowing for an increased blood flow through the vessels & lowering the systemic BP - decreases cardiac workload
- Prevent & treat attacks of angina pectoris
- Sublingual tablet, translingual spray, IV solution, transdermal patch, topical ointment or paste, or transmucosal agent
- Rapidly absorbed, metabolized in the liver, excreted in the urine; crosses placenta & enters breast milk
- Adverse effects - HA, dizziness, weakness, n/v, incontinence, hypotension, reflex tachycardia, syncope, angina, flushing, pallor, increased perspiration
- Do not combine nitrates with sildenafil, tadalafil, or vardenafil - hypotension & cardiovascular events
- Lay down or sit prior to administration d/t low blood pressure causing lightheadedness or dizziness
- Sublingual - under the tongue, patient should feel a fizziness or burning sensation which indicates potency
- Sublingual - can be repeated in 5 min if relief is not felt to a total of 3 doses 5 min apart
- If topical application is required rotate sites to decrease risk of skin abrasion & breakdown
Anticholesterol Medications - Statins
- Atorvastatin, pravastatin, rosuvastatin, simvastatin
- Blocks action of HMG-CoA reductase enzymes & leads to lower serum cholesterol & LDL levels & higher serum HDL levels
- Absorbed from GI tract - first pass metabolized in liver, excreted in urine & feces
- Crosses placenta & breast milk
- Peak effect : 2-4 weeks taken at night
- Adverse effects - flatulence, abdominal pain, cramps, n/v, constipation, HA, dizziness, blurred vision, insomnia, fatigue, cataract development, increased concentrations of liver enzymes, acute liver failure may be reported w/atorvastatin and Fluvastatin
- Rhabdomyolysis may occur
- Toxicity increases if taken with grapefruit juice, digoxin, & warfarin
- Used in conjunction w/diet to treat hypercholesterolemia & CAD
?
___ is an enzyme in the synthesis of cellular cholesterol
If this enzyme is blocked, serum cholesterol & LDL levels decrease b/c more LDL’s are absorbed by the cells for processing into cholesterol
On the other hand, HDL levels increase
HMG-CoA
?
Is a breakdown of muscles w/waste products that can injure the glomerulus & cause acute renal failure
The risk for this increases if statins are taken w/erythromycin, cyclosporin, gemfibrozil, niacin, or antifungal drugs
Rhabdomyolysis
Drugs Affecting Blood Coagulation - Antiplatelet
- Decrease formation of platelet plug & inhibit adhesion & aggregation to vessel walls
- ASPIRIN, clopidogrel (Plavix)
- Treat cardiovascular disease prone to thrombus
- Adverse effects: bleeding, HA, dizziness, weakness, n/v, rash
* Acute aspirin toxicity w/hypercapnia possible leading to fever, coma & cardiovascular collapse; nausea, dyspepsia, heartburn, epig discomfort, GI bleeding, occult blood loss, dizziness, tinnitus, difficulty hearing & anaphylactoid reaction
Drugs Affecting Blood Coagulation - Anticoagulant
- Interfere with normal clotting process
- Heparin, coumadin (Warfarin), dabigatren (Pradaxa), rivaroxaban (Xarelto), apixaban (Eliquis)
* Warfarin (oral) causes decrease in Vitamin K-dependent clotting factors - EXTENDS CLOTTING TIMES - maintains anticoagulation
* Absorbed in GI tract; metabolized in liver; excreted in urine & feces
* Onset 3 days, effects last 4-5 days
* Antidote - Vitamin K
* Stomach bloating, cramps, loss of hair & skin rash, orange-yellow discoloration of the urine
* Report: any bleeding, black tarry stools, cloudy or dark urine, sore throat, fever, chills, severe HA or dizziness
* Wear medical bracelet
* PT/INR labs - 1.5 - 2.5x control
Drugs Affecting Blood Coagulation - Anticoagulant cont’d
Anticoagulant
- Heparin blocks formation of thrombin
- Treats acute venous thrombosis, pulmonary embolism, atrial fibrillation
- IV or SC - usually inpatient acute (oral for outpatient)
- Immediate onset, excreted in urine
- APTT 1.5 - 3 times the control value
Thrombolytic
- Urokinase
- Breakdown thrombus
Low-Molecular-Weight Heparins
- Enoxaparin (Lovenox)
- Block clotting factors II & X
- Usually used after surgery & prolonged bedrest to prevent clot formation
- Continued 7-14 days post-op
Warfarin-Sodium (Coumadin)
Heparin
Bleeding Precautions
RANDI
R = Razor → electric
A = Aspirin → NO!
N = Needles - small gauge
D = Decrease needle sticks
I = Injury - Protect from
Implement when:
Using anticoagulants
Liver disease present
Platelets ↓ 150,000
Hemophilia present
Using thrombolytic meds
Observe for hematuria, nosebleeds, gingival bleeding, bruising
Cardiopulmonary Resuscitation
___ - cessation of heart function; pale grayish skin; absence of femoral or carotid pulses, apnea, pupil dilation
Brain is damaged by lack of O2 within 4-6 min
CPR - cardiopulmonary resuscitation
> Effective, uninterrupted chest compressions
> Push hard, push fast in center of chest
> Administer 100 compressions per minute
> 30 compressions to 2 breaths (for all victims except newborns)
Cardiac arrest
?
___ or ___ arrest is the cessation of breathing; it can be caused by blocked airway or it can occur after cardiac arrest; be sudden or preceded by increased, labored breathing
Respiratory (or) pulmonary
Decreased Cardiac Output
- Decreased ability for heart to pump
- S/S : confusion, agitation, decreased LOC, cool/clammy/mottled extremities, delayed capillary refill, diminished peripheral pulses, hypotension, tachycardia @ first then bradycardia, thready pulse, JVD, increased RR, breathlessness, orthopnea, edema
- Assessment : skin, LOC, HR, RR, & BP, fluid balance & weights, edema, orthopnea, reports of fatigue
- Diagnostic Testing;
> ABGs, CBC, electrolytes, kidney function (creatinine & BUN), cardiac biomarkers (CK, LDL, AST), chest x-ray, ECG
Nursing Interventions
- Record I&O
- Limit fluid & Na+
- Small frequent meals _ fatigue
- Auscultate: heart sounds - rate/rhythm/S1,S2,S3,S4
- Monitor bleeding
- Monitor anxiety (speak calmly & quietly; do not leave patient alone; give clear info)
Nursing Interventions cont’d
- Position: Semi-Fowler’s; no crossing legs; frequent ambulation
- Administer O2 & medications
- Schedule nursing care to allow rest & minimize fatigue
- ROM exercises
- Antiembolism stockings (TED hose) [thrombo-embolus deterrent]
- Sequential compression devices (SCDs)
Preload & Afterload
Preload
- Volume of blood in ventricles at end of diastole (end diastolic pressure)
Increased in : hypervolemia, regurgitation of cardiac valves, HF
Afterload
- Resistance left ventricle must overcome to circulate blood
Increased in : hypertension, vasoconstriction
↑ afterload = ↑ cardiac workload
Picture a balloon…
You are filling the balloon with water. Preload would be the amount of water in the balloon once you fill it
Now hold the filled balloon by the top and squeeze the top gently; then with your other hand hold the balloon in your hand and try squeezing the water out of the balloon while maintaining the top squeezed… afterload would be the amount of force you would need to squeeze all the water out of the balloon
