-
Structures of the Cardiovascular system
- heart: 4 chambers. composed of 3 layers
- blood vessels
- arteries, arterioles
- veins, venules
- capillaries
-
layers of the heart from inside out
- endocardium
- myocardium
- epicardium (which is the inner layer of the pericardium)
-
when are murmurs heart
- when blood flow is turbulent due to dysfunctional valves
- the vavles may get affected due to accumulation of lipids, degeneration of collagen and fibrosis
-
when does coronary perfusion happen? body tissue perfusion?
- during diastole- when the heart is relaxed
- during diastole blood fills the sinuses that perfuse the heart
- body tissue perfusion happens in systole- when the heart is contracting
-
order of contruction
- sa node
- av node
- bundle of his
- right bundle branch
- purkinje fibers
-
what is the sa node called
- the pacemaker of the heart
- a reduction in the # of pacemaker cells can account for sinus dysrhythmias, esp in older patients
-
reduction in the number of conduction cells in internodal tracts, bundle of his and bundle branches
contribute to the development of atrial dysrhythmias and heart blocks
-
connect the node to the portion of the electrocardiogram
- sa node: pwave
- av node and bundle of his: first part of the PR interval
- purkinje fibers: rest of the flat line between the pwave and q wave
- ---^----
-
systole
- contraction of heart muscle
- heart squeezes- the motion and effort that the heart is going through
-
ejection fraction
- the percentage of blood that was in the ventricles that being pushed out every systolic contraction
- healthy is ~80%
-
Diastole
- relaxation of the heart muscle
- blood is filling the chambers and pooling
-
Stroke volume
- amount of blood ejected with each heartbeat
- a volume rather than a percentage like EJ is
-
what ejection fraction can signal that something is wrong
60% or lower
-
cardiac output
- stroke vol x heart rate
- amount of blood pumped by each ventricle in 1min
- normal: 4-8L/min
-
cardiac index
- cardiac output divided by body surface area
- larger people have a smaller one
- normal: 2.8-4.2L/min
-
factors affecting cardiac output
- preload: measures volume in ventricles at the end of diastole
- contractility: strength of the heart- ability for it to actually pump. when the heart is working really hard it will hypertrophy then eventually fail
- afterload: how much resistance the left ventricle is pushing against. your systemic vascular resistance aka blood pressure
-
comparison of artery, vein and capillary
- artery has thick muscular and elastic middle coat
- vein has a thin middle coat
- both arteries and veins have an outer coat and an endothelial innermost lining
- capilaries are composed of endothelial cells
-
what is a way that DVT/emboli can originate
- all vessels are lined with endothelial tissue
- if that tissue is disrupted, then the clotting cascade will begin which can cause DVT/emboli
-
what regulates the cardiovascular system
- autonomic nervous system
- baroreceptors
- chemoreceptors
-
autonomic ns in regulating the cardiovascular system
- controlled by both the parasympathetic and symp ns
- parasympathetic slows everything down why the sympathetic speeds things up (bp, hr, cardiac output)
-
baroreceptors
measure pressure in the arteries (afterload) and signal to the brain to control the cardiovascular system
-
chemoreceptors
- measure chemicals in the blood
- mainly Co2, pH and O2
-
where are baroreceptors and chemoreceptors located
- both are at the start of the carotid arteries and the aortic arch
- chemoreceptors can also be found in the medulla
-
cardio-pulmonary relation
- cardiac system is very closely related to the pulmonary system- theyre next to eachother and share the same space and blood supply
- if you have lung disease, it will eventually affect the heart and vice versa
- the cardiac system has more function than pulmonary so it can compensate
-
how can the cardiac system compensate for injury
- vascularly
- electrically
- mechanically
-
how to calculate blood pressure
cardiac output x systemic vascular resistance
-
what if your automated bp seems off
always take a manual bp
-
Doppler ultrasonic flowmeter
- used to measure systolic BP when it is very hard to hear a bp and the automatic isnt picking it up
- this often is needed when BP is too low
-
how to use doppler
- put it over the artery and listen when you inflate the cuff and listen for it to go away then increase the cuff 20-30mmHg more then slowly let it out and listen
- when the sound comes back thats your systolic- you wont get the diastolic
-
what are some reasons bp could be really low
- sepsis
- shock
- bleeding out
- autonomic dysfunction
- medication related reasons
-
pulse pressure
- the difference between SBP, and DBP
- normally about 1/3 of the SBP
- exercise can increase pulse pressure
- narrowing means going into shock or hypovolemic
-
mean arterial pressure
- average pressure within arterial system that is felt by organs in the body
- taking both SBP and DBP into consideration and figuring out how much blood is at the vital organ
- we want it to be at least 60, if its less, the vital organs are not getting perfused and theyre getting ischemic and body will go into shock
- MAP= (SBP+2DBP) /3
-
Gerontologic considerations
- when people get older, the elasticity in the blood vessels decreases bc vessels cant stretch and there is increased resistance and therefore hypertension
- elastin is lost with age and arterial stiffening occurs causing progresssive fibrosis which may increase systolic bp or a decrease/no change in DBP- increased pulse pressure
- risk for CVD increases with age
- CVD is leading cause of death in those over 65
-
why do risk factors increase as we age?
- increased collagen, decreased elastin
- decreased response to stress
- heart valves become thick and stiff
- number of pacemaker cells decrease
- decreased number and function of B-adrenergic receptors
-
postpradinal hypotension
- hypotension after eating
- bc esp after a eating a big meal, blood will rush to your gi system and be lower in other areas since your body cant compensate when you get old
- this increases fall risk at older age
-
why do you need to ask all the gordon questions with the heart
- bc the heart affects the whole body so its hard to do a focused one
- if you think its cardiac related you have to go through the whole process
-
genetics and cardiovascular problems
- HUGE LINK
- CAD: lipoprotein gene links
- Cardiomyopathy: autosomal and x linked dominant mutations
- hypertension: genetic, environmental and lifestyle factors- will also put you at risk for CAD and heart conditions
ask if any first degree relatives have CVD , how they died if they did and what meds they are/were on
-
grading of pulses
- 0 absent
- 1+ weak
- 2+ normal
- 3+ strong
- 4+ bounding
-
anatomical landmarks
- aortic area: 2nd right ICS
- pulmonic area: 2nd Left ICS
- Erbs point: 3rd left ICS
- Tricuspid: 4th left ICS
- Mitral (Apex): 5th left ICS at midclavicular line
-
what to look for when palpating
-
thrills
- decreased vascular compliance
- theres more resistance- its narrower and the blood is flowing through more turbulently
- a higher pitched noise
-
what if your PMI is close to axilary line or further than 5th ICS
youre heart is enlarged
-
Know where the heart sounds line up on an EKG
-
ST segment elevated by a couple squares
the heart muscle is dying and they are having an active MI
-
murmurs
- turbulance of blood going across valves- a valve problem
- graded on a 6 point Roman Numeral scale of loudness and recorded as a ratio
-
grades of heart murmurs
- 1/6: you can hardly hear it, need a very quiet room
- 2/6: quiet, but clearly there
- 3/6: louder clear
- 4/6: loud, with associated thrill
- 5/6: very loud with clearly palpable thrill
- 6/6: so loud you can still hear it when lifting your stethescope off the body- generally these patients will need a valve replacement
-
pericardial friction rubs
- when ascultating you have the linings of the heart wall rubbing up agaist eachother with each beat
- best heard at the apicies when PT is holding breath to differentiate from a pleural friction rub
-
pericarditis
- inflammed surfaces of the pericardium move against eachother
- high pitched scratchy sounds
- may be intermittent and last days to hours
-
main cardiac biomarker
- troponin I and T
- sensitivity and specificity of this exceeds other biomarkers
- given off within 4-6 hours
- peaks 10-24 hours
- detectable for up to 10-14 days after event
-
other cardiac biomarkers
- Creatine kinase
- Copeptin
- Myoglobin
- CRP
- Homocysteine
-
creatine kinase
- 3 types of isoenzymes- brain heart and skeletal. youre looking for the MB (myocardial)
- CK enzymes are found in a variety of organs and tissues
- rises in 3-6 hours
- peaks 12-24 hours
- returns to baseline in 12-24 hours
- takes a lot longer than troponin to peak
- monitored seriallly0 every couple hours until troponin peaks- gives drs a timeline and how bad it is
-
myoglobin
- less common biomarker
- elevation is a sensitive indicator of very early myocardial injury, but lacks specificity for MI
-
-
CRP
- C-Reactive protein
- marker for inflammation
- linked to atherosclerosis, rather than MI
-
Homocysteine
- represents genetic markers
- elevated levels represent increased risk for CAD, peripheral vascular disease (PVD) and stroke
-
additional blood test for assessment of Cardiovascular System
- cardiac natriuretic peptide markers
- serum lipids
- lipoprotein
-
natriuretic peptide markers
- 3 types: Atrial natriuretic peptide
- B-type natriuretic peptide
- C-type natriuretic peptide
-
most important natriuretic peptide
- Btype
- used to differentiate whether the problem is cardiac or pulmonary
- if it is cardiac problem, can also be used to assess pulmonary
- tells you if the lungs are affecting the heart to the point where the heart is backing up and failing
- patients often SOB with edema that comes from pul. congestion and causes heart to pump forward
- these PT have pitting edema and get diuretics, lasics, foleys,
- fluid builds up and affects the heart
- Increased BNP levels signify heart failure
-
serum lipids
- these are all naturally made by the liver, but if they are inexcess or their metabolism is uncontrolled, the patient is at risk
- triglycerides
- cholesterol
- phospholipids
-
Lipoprotein
- lipids bound to proteins
- again we need them, but not in excess
- lipids must bind proteins to circulate the blood
-
classes of lipoprotein
- chylomicrons
- LDL: bad, we want these low
- HDL: Good, we want this high
- VLDL: bad, we want this low
-
What increases risk of CAD lipoproteins
- triclycerides and LDL increase risk
- HDL decreases risk
-
cholesterol hdl ratio
- total cholesterol/HDL
- high ratio= higher risk for CAD and MI
- your HDL can be really high, but if yourLDL is really high too its not doing its job
-
other serum lipoproteins
- Alipoprotein A-I (Apo A-I)
- Apolipoprotein B (Apo B)
- Lipoprotein (a) [Lp(a)]
-
explain troponin leak
- if troponin is being leaked, it is very specific to dying cardiac muscle, so you may not have a whole area that died but somewhere is dying and its leaking out
- if you are tachycardica nd your heart is working really hard for a long time your trop will bump
- troponin leak doesnt mean primary MI, it means the heart is getting stressed- those tropes will peak and go down a lot quicker
- level above .4 is something we look at .8, we worry and above 1 is an actual MI
- troponin is both a warning sign and a sign of primary MI
- it will get really high before peaking even as high as 10 if person has MI
-
why is chest x ray important in cardiac assessment
it can help you see heart size and differentiate between cardiac and pulmonary symptoms
-
Electrocardiogram types
- Resting or ambulatory
- or holter monitor
-
ambulatory EKG monitoring
if someone doesnt have symptoms and normal EKG at rest but gets it on movement, you want to get an ambulatory one to see whats going on when theyre symptomatic
-
holter monitor
- event monitor or loop recorder
- these patients go home with this and it monitors them at home for events
- its remote accessed and if theres a lethal arrhythmia it will alarm the hospital
-
exercise/stress testing
these are for patients that are stable
-
echocardiogram
- ultrasound
- sound can be sternal or transesophageal to get a better pic of the valves from behind the heart
- used to look at Ej. fraction and the motion- the mechanical movement of the heart and its ability to pump forward
- can also look at blood flow and make sure its not backing up
- can be with or without contrast
- provides info on structures/motion of heart
- stress echocardiography
- can also monitor if valves are moving efficiently and closing all the way
-
preparing a patient for a transesophageal echocardiogram
- the nurse should ask patient to remove dentures and place a bit block in the mouth
- this is done bc an ultrasound transducer will need to be swallowed and passed through the esophagus
-
nuclear cardiology
- a map
- looking at the heart and figuring out where the problem is
- can be done in stress (walking on the treadmil or with medication that mimics stress)
- MUGA scan
- Stress perfusion imaging
-
Other diagnostic studies of cardiovascular system
- iv meds to dialate coronary arteries: stimulates excercise effects if they cant move
- no stress test if pt is symptomatic
- SPECT: shows aller areas- if everything else comes back negative and pt still symptomatic intermittently, this will be used. uses isotopes to go in and look at specific areas of the heart
- PET stress test: up and coming. measures metabolisma nd how hard tissue is working. dead will look different from tissue working really hard
- CMRI: cardiovascular MRI- if other tests negitive. not common
- Cardiac CTL map of heart vasculature with contrast so you can see perfusion, where there are blockages. you can also do w/o contrast to see if calcification is forming for artherosclerosis risk
- CT angiography
- Calcium scoring screening
-
invasive diagnostic tests of the cardiovascular system
- Cardiac catheterization
- coronary angiography
- intravascular ultrasound
- fractional flow reserve
- electrophysiology study
-
cardiac catheterization
- right sided: a diagnostic procedure performed through veins (femoral or cephalic) to measure pressures. you can also float a swan through venous circulation into right side of heart to measure preload at diastole right before blood from vena cava goes back into the heart, then measure right atrium then right ventricle then into pul artery and blow it up to wedge balloon in there and the tip of the other side of the balloon can measure the other side which is the systemic vascular resistance
- left sided: to evaluate coronary arteries. goes through arterial system, either brachial artery or femoral. goes to left side, only areas that cand do PCIs can do this bc left side is very high risk and if you puncture anything they need heart surgery- surgeon must be there
-
why is nursing care surrounding cardiac caths important
- if they have allergy to die for angiogam
- tell them what to expect
- if going through groin- lay flat with legs strait and stay like that for a while after closing up
- assess for bleeding, infection, signs of perforation
- look at peripheral pulses and perfusion (color, etc)
- highest priority for a patient who has undergone cardiac cath is to first asses the site for signs of hemorrhage. AFTER this, you can do pain, bp and iv site assessments
-
Coronary angiography
- put dye in and see where the blockages are during the cath so when they do surgery they know where to go in from and open up
- uses contrast medium to identify coronary blockages
-
intravascular ultrasound
- an ultrasound fed through much of the same way as a cardiac cath
- care will be similar
- looks at how bad it is
- done with coronary angiography
-
frictional flow reserve
- wires go in like a left sided cath and goes in and figures out flow and how much flow is going into the carotid artery to assess stroke risk
- care for pt is just like in cardiac cath
- special wire measures pressure and flow in coronary artery
-
Electrophysiology study
- rather than looking at the flow and anatomical space, it looks at the electrical system and if theres any extra pacemakers
- important bc those with tachyarrhythmias go in and out of tachy quickly
- you can go in and see whats causing it and what needs to be done to fix it
- provides info on cardiac conduciton
-
TEE (Transesophageal electrocardiograph)
Transesophageal echocardiography (TEE) evaluates mitral valve disease and endocarditis vegetation in the patient. Complications of this procedure include tearing of the esophagus, hemorrhage, dysrhythmias, and transient hypoxemia. Some contrast media cause nephrotoxicity in patients; however, transesophageal echocardiography does not involve the injection of contrast medium into the patient’s heart. Increased levels of lactate dehydrogenase is not a complication of the procedure.
|
|