Exam #3 Flashcards
structures and fxns of cardo system
- heart
- 4 chambers
- composed of three layers: endocardium, myocardium, epicardium
- pericardium: fibrous sac that heart sits in and holds 15 ml of fluid
- left ventricular wall is 2-3 times thicker than right
cardiac valves
- mitral: left vent & left atria
- tricuspid: right vent & right atria
- pulmonic (semilunar): right heart, keeps blood from going into pulmonary artery when heart is pumping
- aortic (semilunar): left heart, keeps blood from flowing into aorta from left vent
auscultation areas
aortic pulmonic erb's point tricuspid mitral
blood flow through the heart
- right atrium receives venous blood from the inferior and superior vena cava –> blood passes through tricuspid valve into the right ventricle
- with contraction, the right ventricle pumps blood through pulmonic valve into pulmonary artery and to the lungs
- oxygenated blood flows from the lungs to the left artium by way of the pulmonary veins
- oxygenated blood flows through mitral valve and into left ventricle
- heart contracts, blood is ejected through the aoritc valve into the aorta and enters systemic circulation
coronary arteries and veins
- coronary circulation: heart’s own blood flow; flows to heart muscles during diastole
- left coronary artery blockage = widow maker
- right coronary artery = provides blood supple to nodes so a blockage here = issues with electrical system of heart and can cause arhythmias
- coronary sinus: most blood from coronary circulation drains into this and emotied into right atrium
heart’s mechanical system
- systole: contraction of myocardium = ejection of blood from ventricles (depolarization) = s1
- diastole: relaxation of myocardium = s2
- s1 = start of systole, “lub”, closure of tricuspid and mitral valves, radial or apical pulse = point of maximal impusle
s2 = strat of diastole, “dub”, closure of aortic and pulmonic valves
cardiac output
- CO: amount of blood pupmed by each ventricle in one minute
- normal = 4-8L/min
- cardiac index: CO/BSA = more precise measure of efficiency of the pumping action of the heart
- normal = 2.8-4.2L/min/m2
- CO is increased with fluid overload and decreased with fluid deficit
** CO = HR X SV
preload
- stretch or filling pressure
- volume in ventricle at the end of diastole
- diuresis (MI, aortic stenosis) if preload is high
- give fluids if preload is low (hypovolemia, vasodilation)
- PAWP = left ventricle preload
- CVP = right vetricle preload
afterload
- squeeze
- peripheral resistance against which the left ventricle must pump SVR and PVR
- heart’s pushing strength to get blood to body
- the more afterload = the less cardiac output
- increased with: HTN, hardened arteries, CAD, pulm HTN, hypoxia, catecholemines
- decreased with: vasodilators, acidosis, oxygen
systemic vascular resistence
- opposition encountered by left ventricle
- increased with vasoconstricotrs, low volume
- decreased with vasofilators, morphine, nitrates, high co2
pulmonary vascular resistance
- opposition encountered by right ventricle
- increased with pulmonary hypertension, hypoxia
- decreased with meds (calcium channel blockers, aminophyline, isoproterenol, oxygen)
contractility
- strength of contraction
- when increased, stroke volume and oxygen demand and increased
- increased with: positive inotropes meds (epi, norepi, isoproteronol, dopamine, dobutamine, digitalis)
- decreased with: negative inonotropes, heart failure, alcohol, calcium channel blockers, beta blockers, acidosis
preload problems
- JVD
- lung sounds
afterload problems
- BP
- skin temp
- pulse pressure
contractility problems
- junction fraction
factors affecting heart rate
- autonomic nervous system (ANS)
- SNS: adrenaline, speeds up everything, vasoconstriction
- PNS: vagus nerve, slows everything down, vasodilation
- baroreceptors (perssure) and chemoreceptors (co2 and o2)
blood pressure
- systolic blood pressure: 60 is needed to perfuse organs
- MAP = (syst BP + 2x dia BP)/3
gerontologic considerations
- risk for CVD increases with age
- CVD leading cause of death in adults >85
- cardivascular changes result of aging, disease, environmental factors, and lifetime behaviors (smoking, drinking)
- heart rate changes: no change in resting supine HR; decreased HR response to stress; HR takes longer to increase for activity and longer to decrease with rest; give a while to relax before taking BP
- BP changes: HTN is not expected with age, increased SBP; decreased or no change in DBP; increased pulse pressure, orthostatic hypotension
- postrandial hypotension = decrease in BP of at least 20 mm hg that occurs within 75 minutes after eating (don’t give BP meds near meal time)
- heart sound changes: murmur from reguritation/narrowing of mitral and aortic valves
- ECG changes: decreased pacemaker cells; sinus and atrial dysrhythmias, heart block, abnormal resting ECG in 50% of elderly
- medication response changes: less sensitive to beta blockers, increased sensitivity to vasopressin (ADH)
- physical changes: dependent edema due to incompetent venous valves
AFIB
- controlled: vent rate 100 HR
risk factors for heart issues
- all are modifiable
- increased serum lipids
- hypertension
- smoking
- sedentary lifestyle
- obestiy
- stress
- DM
subjective heart assessment
- allergies to iodine (contrast procedures)
- familiar disorders
- constipation (vagus nerve stimulation can cause fainting)
- exercise intolerance
- PND (paroxysmal nocturnal dyspnea), orthopnea, sleep apnea
- sexual problems (vagus nerve)
stroke volume
- SV: volume of blood (in ml) ejected with each heartbeat
- normal = 50-100ml
- determined by preload, afterload, and contractility
- SV Index: adjusted for BSA
- normal = 25-45ml
- increased with volume overload, inotropy, hyperthermia, meds (digitalis, dopamine, dobutamine)
- decreased with impaired cardiac contractility, valve dysfunction, CHF, bet blockers, MI
- factors affecting stroke volume: preload, afterload, contractility
** CO = HR X SV
preload
- stretch or filling pressure
- volume in ventricle at the end of diastole (totally filled ventricle)
- increased with: fluid overload, MI, and aortic stenosis
- decreased with: hypovolemia, and vasodilation
afterload
- squeeze
- peripheral resistence against which the left ventricle must pump
- the more afterload = less cardiac output
- increased with: HTN, hardened arteries, CAD
- decreased with: vasodilators, acidosis, oxygen
- Systemic Vascular Resistence SVR: opposition encountered by left ventricle; increased with vasoconstrictors, low volume; decreased with vasodilaros, morphine, nitrates, high co2
- pulmonary vascular resistance PVR: opposition encountered by right ventricle; increased with pulmonary hypertension, hypoxia; decreased with meds
contractiity
- strength of contraction
- when increased, stroke volume and oxygen demand are increased
- increaesd with meds (epi, norepi, isoproteronol, dopamine)
- decreased with: heart failure, alcohol, calcium channel blockers, beta blockers, acidosis
factors affecting stroke volume
- CO = HR X SV
- preload
- afterload
- contractility
preload problems
- JVD
- lung sounds
afterload problems
- BP
- skin temp
- pulse pressure
contractility problems
- ejection fraction
factors affecting Heart Rate
- autonomic nervous system
- sympathetic nervous system: adrenaline, speeds everything up, vasoconstriction
- parasympathetic nervous system: vagus nerve, slows everything down, vasodilation
- baroreceptors (pressure sensors) and chemoreceptors (sense co2 and 02)
Blood Pressure
- systolic: 60 needed to perfuse organs
gerontologic considerations
- risk for CVD increases with age
- CVD leading cause of death in adults >85
- cardio changes result of: aging, disease, enviro, lifetime behaviours (drinking, smoking)
- heart rate changes: no change in resting supine HR, decreased HR response to stress
- takes longer for HR to increase with activity and decreae with rest
- BP changes: HTN is not an expected result of aging
- increased systolic with decrease/no change in diastolic
- orthostatic hypotension
- postprandial hypotension = decrease in BP of at least 20 mmhg that occurs within 75 minutes ofter eating (don’t take BP right after a meal)
- heart sound changes: murmur from regurgitation/narrowing of mitral and aortic valves
- ECG changes: (decreased pacemaker cells)
- sinus and atrial dysrhythmias (Afib)
- abnormal resting ECG in 50%
- medication response changes: less sensitive to beta blockers, increased sensitivity to vasopressin (ADH)
- physical changes: dependent edema due to incompetent venous valves
Afib
- controlled: vent rate 100 HR
cardio risk factors
- increased serium lipids
- HTN
- smoking
- sedentary lifestyle
- obesity
- stress
- DM
- all modifiable
cardio assessment
- allergies to iodine (contrast)
- familial disorders: heart disease before age 55
- constipation: vagust nerve stimulation
- exercise intolerance
- dependent rubor: A redness or purple color of a leg when it is in the dependent or lowered position. If the leg blanches on elevation it may be a sign of lower leg ischemia
- JVD
- venous stasis ulcers
arterial wound vs venous wound
- arterial: smaller, deeper, dryer
- venous: large, shallow, wet, edema/weeping
PMI
point of maximal impulse
- if it is found below 5th intercostal space then means enlarged heart
s1
closure of tricuspid and mitral valves
s2
closure of aortic and pulmonic valves
- s2 splitting heard during expiration not good
s3
ventricular gallop
- kentucky
s4
atrial contraction (before s1)
- CAD or cadiomyopathy
- tennessee
cardiac lab markers
- troponin: protein released after an MI, highly specific to cardiac tissue - greater than 2.3 = positive for MI
- CK-MB: iozyme released after cardiac tissue injury, levels increased 4-6 hours after MI, >4-6% = positive for MI
- Myoglobin: protein sensitive for MI, rises 30-60 minutes after MI, range is about 24
- BNP (b-type naturetic peptide): determines whether dyspnea is from a cardiac or respiratory cause, >100 = heart failure
risk predictors
- c-reactive protein: marker for inflammation; risk factor for CAD
- homocysteine: elevated levels increased risk for CAD, PVD, and stroke
serum lipids/lipoproteins
- serum lipids/lipoproteins
- triglycerides (60 is low risk)
- LDL (
chest x ray
- shows:
- contours of heart
- displacement, enlargement
- fluid
- pulmonary congestion
- size of heart
electrocardiogram
- ECG
- records cardiac electrical activity
- event monitor or loop recorder
exercise or stress test
echocardiogram
- ultrasound of heart
- with/without contrast
- shows: structures of heart, work of the heart, size, pericardial sac, ejection fraction
nuclear cardiology (MUGA)
- IV injection of radioactive isotope, pay still for 20 minutes with arms up, may have repeat scans
- structural info and injection fraction
MRI
- noninvasive, but must lie still
- cant do if they have a pacemaker
- ejection fraction, MI recovery
CT
- visualizes heart anatom, circulation, and big vessels
- can be performed instead of cardiac cath
- calcium can be seen in atherosclerotic plaques
- heart anatomy, circulation, vessels, calcium deposits, atherosclerotic plaque
cardiac catheterization
- invasive outpatient procedure
- angiography involves injection of dye, shows coronary lesions
- intracoronary ultrasound done with angiography, shows vessel walls and plaque
- obtains info about 02 levels, pressure readings in heart chambers, structures and motions of the heart,
- insertion of catheter into vein
- determines source of dysrhythmias
- pre-op: pt needs to be NPO for 6 hours before, requires sedation, cough or deep breath when dye is injected
- post op: neurovascular checks q 15 minutes x 1 hr, compression device over injection site, close monitoring of VS and ECG
- complications: bleeding, hematoma, allergic reaction, infection, clot, aortic dissection, dysrhythmias, MI, stroke, puncture ventricles or lung
regulation of BP
BP = CO X systemic vascular resistence
- sympathetic nervous system: increases HR, vasoconstriction, release od RENIN from kidneys
- baroreceptors: send inhibitory impulses to the sympathetic vasomotor center in the brainstem
- renal system: control sodium excretion and ECF volume, increase venous return and SV, RAAS system
- endocrine system: epinephrine increases HR and contractility, increased blood sodium osmolarity stimulating release of ADH
hypertension
- systoldic > 140, diastolic > 90
- diastolic will increased to age 55 then go down, systolic stays the same
prehypertension
- systolic 120-139, diastolic 80-89
isolated systolic HTN
- systolic > 140 with diastolic
psuedohypertension
- false HTN with severe atherosclerosis
- arteries so hard they can’t collapse when BP cuff is on arm
causes of HTN
- primary: 95% of people with HTN, no identifiable cause
- secondary: 5% of those with HTN, caused by something specific that can be identified and treated
- suspect if >50, suddenly develop high BP
pathophysiology of HTN
- heredity
- water/sodium retention
- altered RAAS mechanism
- stress
- SNS hyperactivity
- insulin resistence
- endothelium dysfunction
risk factors for HTN
- age >50
- alcohol > 1oz/day
- smoking
- DM
- high serum lipids
- high sodium
- men 55
- obesity
- AA
- sedentary lifestyle
- socioeconomic status
- stress
S/S HTN
- silent killer - S/s often appear after organ disease occurs
- fatigue
- activity intolerance
- dizziness
- palpitations
- angina
- dyspnea
complications with HTN
- hypertensive heart disease: CAD, left ventricular hypertrophy, heart failure
- cerebrovascular disease: atherosclerosis, #1 cause of stroke, HTN, encephalopathy
- peripheral vascular disease: PVD, aortic aneurysm, aortic dissection
- nephrosclerosis: end-stage renal disease, renal dysfunction
- retinal damage: blurred vision, retinal hemorrhage, blindness
diagnostic studies for HTN
- UA, BUN, creatinine (urinalysis)
- electrolytes
- blood glucose
- lipid profile
- uric acid
- ECG
- echocardiogram
treatment for HTN
- goal: BP
lifestyle modificaitions for HTN
- weight reduction
- DASH eating plan
- sodium reduciton
- limit alcohol
- regular physical activity
- avoidance of tobacco use
- stress management
dietary changes for HTN
- DASH eating plan:
- emphasizes fruits, veggies, fat-free or low fat milk, whole grains, pultry, beans, seeds, nuts
- decreased red meat, satl sweets, added sugars, sugarded beverages
- no restriction on caffein or protein
- sodium restriction:
drug therapy for HTN
- diuretics
- beta blockers
- ACE inhibitors
diuretics
- lasix, hydrochlorothiazide, sprionalactone (K+ sparring)
- used for HTN, fluid overlaod
- decreased preload by decreasing fluid buildup
- side effects: low potassium, low magnesium, dehydration
- if K+ is low, digoxin toxicity is a higher risk
- take in the morning
beta blockers
- atenolol, betaxolol, esmolol
- used for HTN, angina, dysrhythmias, post-MI – not recommended for heart failure or asthmatics
- blocks the effects of epi, decreases HR, lowers BP lowers cardiac output, vasodilates, decreases contractility
- side effects: fatigue, impotence, wheezing, SOB
ACE inhibitors
- benazepril, captopril, enalapril, lisinopril
- used for: HTN, heart failure, diabetes (protects kidneys), can prevent heart attack and stroke
- lowers levels of antiotensin II, lowers BP, vasodilates (Decreased afterload)
- side effects: dry cough, low BP, high K+, angioedema (swelling of lips and face)
- dont take with ASA or NSAIDs
Angiotensin II receptor blockers ARB
- candesartan, eprosartan, losartan
- used for: HTN, heart failure, give if unable to tolderate ACE
- blocks angiotensin II from having any effect, lowers BP, vasodilates
- side effects: high K+, decreased kidney fxn
calcium channel blockers
- diltiazem, verapamil, amlodipine, clevidipine
- used for: angina, HTN, dysrhythmias, do not use after MI or with heart failure
- interrupts the movement of calcium into the cells of the heart, vasodilates (Decreased afterload), decreases contractility (pumping strength)
- side effects: bradycardia, low BP, headache, dizziness, nausea
- DO NOT give with grapefruit juice
alpha adrenergic blockers
- clonidine, hytrin, cardura
- used for: HTN, BPH
- vasodilates, lowers BP. lowers cardiac output
- side effects: dry mouth, sedation, fatigue, impotence, low BP
- dont take with alcohol or sedatives, may need to take at bedtime
vasodilators
- nitrates
- used for: angina, HTN, MI, heart failure
- vasodilates (decreases afterload), decreases preload
- side effects: headaches, low BP, dizziness
- must monitor BP (above 100 to give), repeat every 5 mins for 3 times
- dont take if take erectile dysfunction meds
drug therapy side effects for HTN
- orthostatic hypotension: HR >50 and BP >100 to give meds
- sexual dysfunction
- potassium: ACE and ARB can make it high
- dry mouth
- nocturia
HTN nursing interventions
- health promotion, lifestyle modifications
- ambulatory/home care
- home BP monitoring
- patient compliance
- need to be seen monthly until BP is stable
proper BP measurement
- proper cuff size
- arm at level of the heart
- measure in both arms and use arm with higher reading
- do not smoke, exercise, drink caffeine 30 minutes before
- sit quietly after resting 5 minutes with arm supported at heart level
- both feet flat on floor
- take first thing in AM and at night
- take two readings, wait 1 minute between
- single value is not as important as a series of values
HTN gerontologic considerations
- higher incidence of ISH (isolated systolic) and white coat HTN
- be careful of auscultory gap
- more sentitive to slight BP changes
- resistant to ACE inhibitors and ARBs
- orthostatic hypo
- postprandial hypotension is common
hypertensive crisis
- can develop over hours or days
- rate of rise, not actual BP, is most important
- MAP is more important than BP
- most common cause is failure to take BP meds
- another cause is cocaine/crack use
- S/S: severe headache, n/v, seizures, confusion, coma, pailledema, tremors, decreased urine output
hypertensive crisis treatment
- goal is to slowly lower BP (decrease MAP by 25% in 1 hour)
- IV sodium nitropursside along with oral BP meds
- check BP q 2-3 minutes
- monitor ECG for dysrhythmias
- hourly urine output
- bedrest
- frequent neuro checks
heart failure
- R. heart failure: peripheral edema, JVD
- L. heart failure: pulmonary edema
- abnormal cardiac fxn involving imparied cardiac pumping and/or filling
- associated with HTN, CAD, MI
- primarily affects older adults
- high morbidity and mortality
risk factors for heart failure
- CAD, age, HTN
- diabetes
- smoking
- obesity
- high cholesterol
- AA