Cardiopulm Unit 1 Flashcards
How does Blood Circulate through the body?
- The Superior/Inferior Vena Cava bring blood back to the heart, it has picked up CO2 from the metabolizing tissues of the body and has given up the oxygen to those tissues. It is entering the heart for gas exchange to remove the CO2 and pick up O2
- Blood is going to the Right Atrium slowly and it will fill it. Eventually the Tricuspid Valve (One of the 2 Atrial Ventricular Valves) will open up, at this point Diastole as a phase is set to begin
- Blood then falls to the Right Ventricle (When this happens Atrial Systole happens, this is when the Right and Left Atrium contract at the end of Diastole to “kick” extra blood into the ventricles)
- When the blood falls the Valve closes and its ready to contract and eject the blood it received through the Semilunar Valve (aka pulmonic valve)
- The blood then gets ejected through pulmonary circulation (through the pulmonary artery), the blood will then land in the capillaries (this is where gas exchange occurs, this is called alveolar capillary interface, where blood and air interact)
- Blood then returns to the heart via the pulmonary veins and lands in the left atrium
- The other AV valve called the Mitral Valve (aka bicuspid valve) will open and the blood will fall into the left ventricle, then atrial systole happens again. The Mitral valve will then close
- The left ventricle will then contract and blood will be ejected into the Aorta passing through the other semilunar valve called the aortic valve. Blood then travels and then it reaches the capillaries of the body where the opposite pattern of gas exchange happens (O2 is deliveres and CO2 is picked)
- The cycle then repeates
Which ventrical is typically more focused on and why?
The left ventricle, because its the biggest part of the heart, its the hearts “pump”. It pumps blood into the body, It has the most myocardium in the heart
With the semilunar valves of the heart (Aortic and Pulmonic) it has a ring around the valve, what is the name of the ring and what does it do?
Its called the Annulus, it surrounds itself around the valve and it anchors itself to the surrounding myocardium.
What are the Pathologies that relate to the 4 valves of the heart?
- Stenosis
- Valvular Insufficiency
Valve Pathologies
What is Stenosis?
A pathological narrowing or constriction that may cause reduced blood flow and potential clinical complications
What can stenosis result in?
If there is a narrowing in a valve, this will make the heart pump harder so it can squeeze blood through a smaller opening.
- Over time that increased stress/strain on the heart might produce changes in the heart structure
Valve Pathologies
What is Valvular Insufficiency?
Valves that do not close properly, often described as “regurgitant”, “insufficient”, or “leaky”
What can valvular insufficiency result in?
This can result in retrograde (backward) blood flow and chronically high-pressure levels, which may lead to arrhythmias
- Over time this may cause pathological changes to the heart
How can Valvular pathologies be assessed?
They can be assessed via ascultation to produce characteristic sounds (like murmurs, etc.)
What are the 3 layers of the heart?
- Pericardium (outermost layer)
- Myocardium
- Endocardium
Layers of the heart
What is the Pericardium?
Whats its function?
This is the outermost layer of the heart. Made of epithelial cells that form a membrane to cover the entire heart. This has sublayers called: Outer parietal pericardium and inner visceral pericardium. The space between both sublayers is known as the pericardial space/cavity and is usually filled with serous fluid to allow to expand and contract will less friction from surrounding structures
The parietal paricardiums function is to anchor the heart to the surrounding structures to prevent excessive movement
What are some examples of pathologies that correlate with the Pericardium?
- Pericarditis
- Pericardial Effusion/Cardiac Tamponade
Layers of the heart
What is the Myocardium?
The muscular layer of the heart. This is the part of the heart that contracts and pumps blood to the body. It has: automaticity, rhythmicity, and conductivity. It does not undergo miotic activity, meaning if there is a myocardial infarction the cells will not regenerate. There are 2 kinds: Mechanical (aka myocytes) and conductive (aka the syncytium)
What is an example of a pathology that correlates with the Myocardium?
Myocardial Infarction
Layers of the heart
What is the Endocardium?
Lines the inner surface of the heart, its valves, and chordae tendinae
What is an example of a pathology that correlates with the Endocardium?
Endocarditis
Where do the L and R Coronary Artery independently branch off of?
The Aorta
The L Coronary Artery spits up into what two arteries? What do they supply?
- The Circumflex A.: supplies the L atrium and lateral/posterior walls of the Left ventricle
- Left Anterior Descending A. (LAD): this supplies the anterior wall and septum (area between the left and right ventricle) of the Left ventricle
What does the R Coronary Artery Supply?
The R Atrium and Ventricle, inferior an posterior wall fo the L ventricle. Supplies SA and AV nodes in most people
What does the Posterior Descending A. (a branch off of the Right Coronary A.) supply?
Supplies inferior Left ventricle and posterior septum. In some people, it also supplies some of the R ventricle
Why are anastamoses important?
These provide collateral circulation. This may be important in the contex of coronary artery disease or other conditions that impair blood flow to the heart muscle
What does the SA Node do?
The Sinoatrial Node (SA) is where the cardio cycle begins in normal circumstances. It depolarizes and will send electrical signals through different fibers where it would reach the AV node and the SA node will dictate the firing of the AV node
Signals start at the SA node and it will sends waves to the AV node. The AV node will then itself depolarize and then send signals down the Bundle of His which will then split into the L and R Bundle Branch then they branch again in to Purkinje fibers. These Purkinje fibers innervate the myocardium of the L and R Ventricle
What is the firing rate of the SA node?
60-100 bpm
The PNS has a constant influence in the SA node, Vagal Tone
What is the firing rate of the AV node?
40-60 bpm
However it doesnt really pace itself. The SA node paces the AV node because it fires faster
What would happen if the SA node failed?
Since the AV node has its own firing rate, it can sustain cardiac functioning. Its just slower (40-60 bpm)
What supplies the SA node?
Its supplied by R Coronary A. in ~ 70% of people and the Circumflex A. in other ~30%
What supplies the AV node?
Its supplied by the R Coronary A. in 90% of the people and by the Circumflex A. in the other 10%
What does the Autonomic Nervous System influence in the Heart?
It influences the Rate of Impulse Generation and Contraction/Relaxation of the Myocardium to meet metabolic demands.
What 2 structures are the Central components that regulate the autonomic control of the heart?
The cortex and the Medulla
What 2 structures are the Peripheral Components of the autonomic nervous system?
Cardiac Plexus and Splanchnic Nerves
Where does the Sympathetic input arise? What does it innervate?
What neurotransmitters does it release?
Arises from cervical and upper 4-5 thoracic ganglia and course through the sympathetic trunk and cardiopulmonary splanchnic nerves.
- Innervates the SA/AV nodes and the atrial and ventricular myocardium to INCREASE HR and Contractility
“Fight or Flight”
- Releases neurotransmitters called catacolamines, mainly epinephrine and norepinephrine
Where does the Parasympathetic input arise? What does it innervate?
Arises from the Medulla and courses through the Right and Left Vagus nerves.
- Innervates SA/AV nodes but other components are sparse. Mainly works to SLOW DOWN HR. It does NOT AFFECT CONTRACTILITY
- Releases neurotransmitters, acetocholyne
With the heart, what does the term “Preload” refer to?
Preload refers to the amount of blood the heart receives during diastole (End systolic volume + venous return).
What does Preload do when the heart receives blood during diastole?
The amount of blood stretches the myocardium, preparing for contraction. The more blood the heart receives, the more it stretches, and the greater the preload.
Analogy: Like filling a ballon with water - the more water you put in, the more the ballon will stretch
With the heart, what does the term “Afterload” refer to?
Afterload refers to the resistance the heart has to overcome to pump blood out
What are 2 factors/conditions that may increase Preload?
- Hypervolemia
- Regurgitation of cardiac valves
Hypervolemia is fluid overload, which means that there is too much fluid or blood in your body, which causes swelling.
What are 2 factors/conditions that may increase Afterload?
- Hypertension
- Vasoconstriction
What is Ejection Fraction (EF)?
This is Stroke Volume / End-Diastolic Volume
What is normal EF?
(Ejection Fraction)
60-70%
What is Cardiac Output?
The amount of blood (in liters) ejected by the heart per minute, depends on HR (beats/min) and SV (mililiters of blood ejected during ventricular systole).
SV = Stroke Volume
An increase in either SV or HR results in an increase Cardiac Output
What is the Normal Value (in L/min) of Cardiac Output?
4-8 L/min
T/F. Ventricles eject all the blood they contain in one beat.
False
In a typical ex. a ventricle is filled with 100ml of blood at the end of its load, but only 60 ml is ejected during contraction. This will equal an ejection fraction of 60%.
- The 100ml is the End-Diastolic volume (EDV) and the 40ml that remains in the ventricle after contraction is the end-systolic volume (ESV)
What is Stroke Volume?
- The amount of blood that leaves within a cardiac cycle
(End-Diastolic Volume - End-Systolic Volume)
Stroke Volume is dependant on 3 factors, what are they?
- Contractility
- Preload
- Afterload
Stroke Volume Factors
What are 3 factors that affect contractility?
- End-diastolic Volume
- Sympathetic Stimuation (Norepinephrine and Epinephrine)
- Myocardial Oxygen Supply
Stroke Volume Factors
What affects Preload?
Review
The End-Diastolic Volume
- End-Systolic Volume + Venous Return
Stroke Volume Factors
What 2 factors affect Afterload?
- Aortic Pressure
- Aortic Valvular Function
What is Blood pressure influenced by?
Cardiac Output x Peripheral Vascular Resistance
…and further influenced by vein and venule capacitance and blood volume
What is Mean Arterial Pressure (MAP)?
The average pressure tending to push blood through the circulatory system, and it reflects tissue perfusion pressure
[(2 x DBP) + SBP] / 3 (This is the equation)
What is the normal range of Mean Arterial Pressure?
70-110mmHG
- 60-65 is critical
What would happen if a patients MAP is less than 60mmHG?
This may indicate inadequate tissue perfusion and should, in a majority of circumstances, lead the clinician to modify the pts position and/or activity to increase MAP right away
This is also a value the medical team will often use to manage pharmacology (e.g., prescribing vasopressors to increase BP)
The Mean Arterial Pressure (MAP) can be increased via:
Increased Inotropy
When examining a peripheral pulse to assess perfusion, it is also important to take note of the rate. (T/F)
False
What is Inotropy?
This is myocardiac contractility
How does the Sympathetic Nervous System affect the heart?
It increases Cardiac Output, and also increases:
- HR
- Contratility
- Automaticitiy
- Conduction Volume
How does the sympathetic Nervous System affect the Veins?
It changes the tone to drive blood back to the heart. Affects Pre-load => Stroke Volume => then Cardiac Output
When grading Pulse Strength, what does 0 mean?
No palpable pulse
When grading Pulse Strength, what does 1 mean?
Faint, but detectable pulse
When grading Pulse Strength, what does 2+ mean?
Slightly more diminished pulse than normal
When grading Pulse Strength, what does 3+ mean?
Normal pulse
When grading Pulse Strength, what does 4+ mean
Bounding pulse
How should we find the Dorsalis Pedis artery?
Its lateral to the extensor hallucis longus tendon on the dorsal surface of the foot, sightly distal to the dorsal most prominence to the navicular bone
Dorsiflex the ankle to eliminate a possible occlusive tightening of skin over artery
How should we find the Posterior Tibial Artery?
Locate the pulse posterior and inferior to the medial malleolus
Invert the ankle to eliminate a possible occlusive tightening of skin over artery
In BPM, what is the normal pulse?
60-100 bpm
What is Tachycardia? What causes this?
An increase in pulse
Causes:
- Congestive Heart Failure (CHF)
- Hemorrhage
- Shock
- Dehydration
- Anemia
- Hyperthyroidism
- Anxiety
- Infection
What is Bradycardia? What causes this?
A decrease in pulse
Causes:
- Heart blocks
- Hypothyroidism
- increased ICP
- use of certain drugs (beta blockers, calcium channel blockers)
What would happen if a patient has an abnormally irregular, weak, slow or rapid pulse, especially if sustained?
This might mean that the heart cannot function properly and requires further evaluation
How should we find the Carotid Pulse?
- Palpate one side at a time
- Gently tilt the head to relax the SCM
- Place fingers near upper neck between SCM and Trachea roughly at the level of cricoid cartilage
- Repeat on the opposite side
- This is the perferred pulse point used during a BLS scenario
With the Carotid pulse, what should we avoid?
- Compression of the carotid sinus which is located at the level of the top of thyroid cartilage
- Simultaneous palpation of both carotid arteries
How do we find Radial Pulse?
Locate pulse lateral to the tendon of the Flexor Carpi Radialis muscle at the distal wrist
How do we find Apical Pulse?
Locate pulse using a stethascope, should be placed over the fifth intercostal space, mid-clavicular line
Which pulse would be more rapid, the radial or Apical?
The Apical pulse may be slightly more rapid than radial because of a slight lag in times as the blood rushes from the heart into the large arteries where it can be palpated.
However if there is a large difference between the values observed (referred to as the pulse deficit), this may indicate presence of cardiac impairment (e.g., an arrhythmia)
What may an Absent or diminished intensity of pulse suggest?
- Peripheral vascular disease
- Decreased cardiac output and bloop pressure with weak or absent pulse
- we should note side-to-side (L vs R) differences in both pulse strength and rate may exist in cases of thromboembolism, and other pathologies
What can severe brady/tachycardia potentially lead to?
A drop in cardiac output
With severe tachycardia, there is little time for ventricular filling (pre-load) which impaired Frank-Starling mechanism
What can moderate-to-severe irregularities potentially lead to?
Drop in cardiac output and/or complaints of palpitations in arrhythmias-especially tachyarrythmias
Why is it that ALL arrhythmias suspected as new or in a worsening state require medical attention?
Because there is now way of knowing the true cause of the irregularity unless the patient is hooked up to an ECG machine. If symptomatic, refer out immediately
What is the primary aim of the Capillary Refill Test?
The primary aim is to gauge how well blood is circulating through the smaller blood vessels in the body
- Apply pressure to the pad (NOT NAIL) of a finger or toe for 5-10 seconds
Should you always take the Manual Pulse Rate over a minute’s length? Why or Why not?
Measuring the pulse for 30 seconds and multiplying it by (2) is sufficient for most populations. That being said:
- Always seek to take full minute to obtain a resting value in someone with an irregularly irregular rhythem
- Consider shorter-time measurements if seeking a time-sensitive pulse rate (e.g., 10-15 seconds if trying to establish rate during or immediately after exertion/exercise)
When should you consider assessing heart rate apically vs. radially?
- When there is severe tachycardia
–The lag in time as the blood rushes from the heart into the larg arteries may make radial palpation challenging - Arrythmias (e.g., artrial fibrillation, premature ventricular contractions)
–With some arrythmias, ventricular contractions may be too weak to empty into the aorta and cause a palpable peripheral pulse. In this scenario, radial assessment may underestimate actual heart rate (a show a pulse deficit)
On the stethoscope, what is the difference between the Bell vs. Diaphragm?
- Bell: low-frequency sounds; use light pressure or else it turns into a diaphragm. Use bell with soft placement for assessment of S3 and S4
- Diaphragm: High-freqency founds; use with firm pressure
What 3 pieces of information does a pulse assessment provide?
Rate, Rhythm, and Strength
When taking BP, the bladder should take up how much of the patients arm?
It should encirlce about 80% of the upper arm
What are some factors that may affect the accuracy of a BP measurement?
- Cuff size and placement
–Too small cuffs overestimate BP
–Too large cuffs underestimate BP - LE positioning
- Speaking moving or having arm unsupported during assessment
- Time spent in resting after most recent exertion
BP reading error related to positioning Technique
How would BP be affected if there is a Full Bladder?
It would be elevated 10-15mmHG
BP reading error related to positioning Technique
How would BP be affected if there is an unsupported back?
It would be elevated 5-10mmHG
BP reading error related to positioning Technique
How would BP be affected if there is an Unsupported Feet?
It would be elevated 5-10mmHG
BP reading error related to positioning Technique
How would BP be affected if there are Crossed Legs?
It would be elevated 2-8mmHG
BP reading error related to positioning Technique
How would BP be affected if the Cuff is over clothing?
It would be elevated 10-40mmHG
BP reading error related to positioning Technique
How would BP be affected if the arm is unsupported?
It would be elevated 10mmHG
BP reading error related to positioning Technique
How would BP be affected if the patient is talking?
It would be elevated 10-15mmHG
What is considered Normal Blood Pressure?
Less than 120mmHG (systolic) and Less than 80mmHG (diastolic)
What is considered “Elevated” Blood Pressure?
120-129mmHG (Systolic) and Less than 80mmHG (Diastolic)
What is considered “High Blood Pressure (Hypertension) Stage 1”?
130-139mmHG (Systolic) OR 80-89mmHG (Diastolic)
What is considered High Blood Pressure (Hypertension) Stage 2?
140 or higher mmGH (Systolic) OR 90 or higher (Diastolic)
What is considered “Hypertensive Crisis”?
Higher than 180mmHG (Systolic) and/or Higher than 120mmHG (Diastolic)
Outpatient HTN Management Algorithm
If you just took BP on a patient and they do not have Hypertension Diagnosis, and they have ≤ 139mmHG systolic and/or
≤ 89mmHG diastolic. What should be done after recieving the results?
- Inform the patient of the reading
- Education the patient on lifestyle modification
- Document blood pressure
Outpatient HTN Management Algorithm
If you just took BP on a patient and they DO have Hypertension Diagnosis, and they have ≤ 139mmHG systolic and/or
≤ 89mmHG diastolic. What should be done after recieving the results?
- Inform the patient of the reading
- Education the patient on lifestyle modification
- Continue current medication regimen
- Document blood pressure
Outpatient HTN Management Algorithm
If you just took BP on a patient and they do not have symptoms of HTN, and they have 140-179mmHG systolic and/or 90-109mmHG diastolic. What should be done after recieving the results?
wait 5 minutes and recheck
- Inform patient of reading
- Determine medication compliance, if appropriate
- Monitor during therapy intervention
- Document blood pressure
- Recheck at next therapy visit
–If still in abnormal range, notify physician
–If in safe range, continue to monitor
Outpatient HTN Management Algorithm
If you just took BP on a patient and they DO have symptoms of HTN, and they have 140-179mmHG systolic and/or 90-109mmHG diastolic. What should be done after recieving the results?
- Inform patient of reading
- Determine medication compliance, if appropriate
- Contact physician
- Obtain medical clearance prior to initiating exercise
- Document blood pressure
Outpatient HTN Management Algorithm
If you just took BP on a patient and they do not have symptoms of HTN, and they have ≥180mmHG systolic and/or ≥110mmHG diastolic. What should be done after recieving the results?
Wait 5 minutes and re-check
- Inform patient of reading
- Determine medication compliance, if appropriate
- Contact physician
- Physician determines next steps
- Hold Exercise
- Document blood pressure
Outpatient HTN Management Algorithm
If you just took BP on a patient and they do not have symptoms of HTN, and they have ≥180mmHG systolic and/or ≥110mmHG diastolic. What should be done after recieving the results?
- Inform patient of reading
- Determine medication compliance, if appropriate
- Contact physician
- Physician determines next steps
- Send to emergency, if unable to contact physician
- Hold Exercise
- Document blood pressure
What are effective lifestyle changes that will help manage HTN?
- Weight Reduction
- Sodium Restriction
- Moderation of EtOH intake
- Regular Aerobic Exercise
EtOH is a scientific way to reference alcohol.
Is a “Manual” BP assessment better than an Automated (machine) assessment?
Vary in their performance
- Automated machines are fine for routine, resting BP assessments and may actually outperform the manual assessment skills of many clinicians
–Arm cuffs are more accurate than wrist cuffs
- Automated machines may struggle with Low BPs, will likely struggle with motion (such as walking or cycling)
- Assessing manual BP at rest and with activity is an essential competency for all professionals
Is there a difference between SBP at the UE vs LE?
- LEs have ~12mmHG higher SBP than UE
–A finding of SBPs lower in the LEs compared the UEs is the basis for diagnosing peripheral arterial occlusion (e.g., of peripheral arterial disease)
–Sometimes the UEs cannot be relied upon for BP assessment due to invasive lines, wounds, previous surgeries, etc. and the values obtained at the LEs should be interpreted accordingly
Systolic Blood Pressure (SBP)
BP at the LEs, the patient should be in supine (placing the cuff at the level of the heart)
In the Pitting Edema Scale, what does a 1+ mean?
Barely perceptible depression (pit)
In the Pitting Edema Scale, what does a 2+ mean?
Easily indentified depression (EID, skin rebounds to it original counter within 15 sec)
In the Pitting Edema Scale, what does a 3+ mean?
EID (Skin rebounds to its original within 15 to 30 sec)
In the Pitting Edema Scale, what does a 4+ mean?
EID (rebound >30 sec)
