Exam 1: AI Lecture 6 Flashcards
What physiological changes occur in the cardiovascular system during the respiratory cycle?
Oscillations in blood pressure due to respiratory cycle
These oscillations are influenced by various factors, including the effects of positive and negative pressure ventilation.
What is the difference between positive pressure ventilation and negative pressure inspiration?
Positive pressure ventilation forces air into the lungs, while negative pressure inspiration relies on creating a vacuum to draw air in.
What is the typical setup of coronary arteries in the majority of individuals?
75% have the posterior descending artery (PDA) branching from the right coronary artery.
What is the significance of left coronary dominance?
In left coronary dominance, the PDA branches from the circumflex artery, which can lead to more serious coronary perfusion issues.
What percentage of people typically exhibit left coronary dominance?
About 15% of individuals.
What happens to pulmonary artery pressure (PAP) and central venous pressure (CVP) during inspiration?
Both PAP and CVP are reduced due to negative chest pressure.
How does inspiration affect preload and afterload on the right side of the heart?
Preload is reduced, but afterload is also reduced for the right side of the heart.
How does inspiration impact the left side of the heart?
The left side experiences reduced preload due to low pressure in pulmonary veins, but afterload does not decrease.
What is the expected effect of positive pressure ventilation on cardiac output?
Initially increases cardiac output, but benefits diminish over time.
What happens to venous return during positive pressure ventilation?
Venous return may be impeded due to increased intrathoracic pressure.
What is the filling pressure in the cardiovascular system typically averaged at?
7 mmHg.
What anatomical change occurs in the left ventricle compared to the right ventricle?
The left ventricle has thicker walls due to higher vascular resistance.
What is a consequence of severe aortic stenosis on the heart’s anatomy?
It leads to ventricular hypertrophy, making the heart walls thicker.
True or False: Positive pressure ventilation is a natural way for the body to breathe.
False.
Fill in the blank: Left coronary dominance means the PDA is a branch of the _______.
circumflex artery.
What happens to the thoracic pressure during positive pressure ventilation?
It becomes more positive, making it harder for blood to fill the heart.
What is the relationship between positive pressure ventilation and afterload on the right side of the heart?
Afterload may increase due to compression effects on the pulmonary artery.
What is one of the primary issues with long-term positive pressure ventilation?
It is unnatural and can lead to various lung problems.
What is aortic stenosis?
A narrowing of the aortic valve that impedes blood flow from the heart
Aortic stenosis can lead to ventricular hypertrophy as the heart works harder to pump blood through the narrowed valve.
What happens to the heart wall in aortic stenosis?
The heart wall becomes thicker due to muscle hypertrophy
This adaptation allows the heart to generate more force to overcome the narrowed valve.
What is pathological hypertrophy?
Abnormal thickening of the heart wall due to increased workload, often from conditions like aortic stenosis or uncontrolled hypertension.
How does hypertrophy affect ventricular wall compliance?
It reduces compliance, making the walls less stretchy and harder to fill with blood.
What happens to the passive filling pressure curve with reduced compliance?
The curve shifts, requiring higher pressures to fill the heart with the same volume of blood.
What does a higher slope in the passive filling pressure curve indicate?
It indicates a structural change in the heart walls, representing decreased compliance.
What is the relationship between slope and compliance in the heart?
The slope of the pressure-volume curve indicates the compliance of the heart; a low slope indicates high compliance.
Fill in the blank: A heart with thin walls and high compliance requires _______ to fill with blood.
relatively low pressure.
What is the first heart sound (S1)?
The sound produced by the closure of the AV valves at the beginning of systole.
- It is low pitched
What is the duration of the first heart sound?
0.14 seconds
- The longest of the 4 heart sounds
What produces the second heart sound (S2)?
Closure of the aortic valve at the end of systole.
- Higher pitched than the 1st heart sound
What is the duration of the second heart sound?
0.11 seconds.
True or False: The fourth heart sound should be present in healthy individuals.
False.
What conditions might allow the third heart sound (S3) to be heard?
Heart failure or in pediatric populations with low compliance ventricles.
What is an aortic stenosis murmur characterized by?
A systolic murmur due to turbulence as blood flows through a narrowed valve.
Describe the murmur associated with aortic regurgitation.
A diastolic murmur due to backflow of blood when the aortic valve leaks.
What is a filling murmur associated with mitral stenosis?
A diastolic murmur that occurs due to difficulty filling the left ventricle.
What adaptations do pediatric hearts have for increased venous return?
They primarily rely on an increase in heart rate rather than stroke volume.
What is the compliance of pediatric ventricular walls compared to adults?
Pediatric ventricular walls are likely less compliant than those of adults.
What can cause both thinning and thickening of the heart wall?
Different types of hypertrophy.
When is the loudest sound during diastole?
At the end of diastole when the atria contract and fill the ventricle
This occurs when there is minimal resistance in the mitral valve.
What is mitral regurgitation?
A problem with backwards flow of blood during systole
It results in a systolic murmur that is loudest at the beginning of systole.
Where is the loudest murmur of mitral regurgitation typically heard?
At the beginning of systole
It tails off towards the end of systole as the atria empty.
Where should you listen for the aortic valve?
On the patient’s right side next to the sternum around the 2nd intercostal space
The stethoscope can also be placed in the neck for better audibility.
Where is the pulmonic valve auscultation site located?
On the patient’s left side close to the sternum in the 2nd intercostal space
This follows the same anatomical principles as the aortic valve.
Where is the tricuspid valve best heard?
The medial left side of the patient in the 5th intercostal space
This is aligned with the flow direction of the tricuspid valve.
Where can the mitral valve be auscultated?
In the 5th intercostal space, slightly further lateral from the tricuspid valve
Positioning the stethoscope towards the left helps in hearing the valve better.
What mnemonic is used to remember the auscultation sequence for heart valves?
All physicians take money
This corresponds to Aortic, Pulmonic, Tricuspid, Mitral.
What causes the splitting of the 2nd heart sound?
The closure of the pulmonic valve after (2nd) the closure of the aortic valve due to the afterload reduction of the right side of the heart during deep inspiration that does not happen in the aorta
This is influenced by pressure differentials and exaggerated during deep inspiration.
What is a phonocardiogram?
A recording instrument that identifies frequencies of heart murmurs
It is useful for detecting low-frequency heart sounds that may not be audible to the human ear. (lower than 20 hertz)
What is the mediastinum divided into?
Superior mediastinum and inferior mediastinum
The inferior mediastinum is further divided into anterior, middle, and posterior sections.
What structures are found in the middle mediastinum?
Heart, pericardium, ascending aorta, superior vena cava, pulmonary arteries and veins
Includes pericardiacophrenic nerves responsible for sensory perception and diaphragm innervation.
What is the role of the pericardiacophrenic nerve?
Senses pericardial pain and supplies innervation to the diaphragm
It is associated with pain from pericarditis.
What can over-dampen the arterial line tracing?
Air bubbles or clots in the arterial line
These can prevent accurate detection of pressure changes and the dichrotic notch.
What happens if the amplifier gain is not set correctly in an arterial line?
Overdamping or underdamping of the arterial tracing
This can lead to difficulties in identifying the dicrotic notch and accurate pressure readings.
The art line amplifier being turned up too high could result in
An underdamped wave form with too many artifacts making it hard to detect the dichrotic notch
The art line amplifier being turned down too low can result in
An overdamped waveform with no dichrotic notch visible at all
clots or air bubbles can also cause an overdamped wave form
What anatomical variations can occur with the circumflex artery?
Anastomosis between the right and left coronary arteries
This connection may be physiologic or non-physiologic and varies among individuals.
What is the significance of the dicrotic notch in arterial line monitoring?
It helps in calculating heart rate and other EKG parameters
A clean and obvious dicrotic notch is crucial for accurate readings.
What is an anastomosis in the context of coronary circulation?
An anastomosis is a connection between blood vessels around the backside of the heart, involving the circumflex portion of the left coronary artery and the posterior descending artery from the right coronary artery.
What does a right-side dominance heart circulatory system indicate?
It indicates that the posterior descending artery (PDA) is coming off of the right coronary artery.
What are epicardial blood vessels?
Epicardial blood vessels are larger coronary blood vessels visible on the surface of the heart.
What are the deeper tissues of the heart wall called?
The deeper tissues are called endocardial tissues or sub-endocardium.
During the cardiac cycle, which blood vessels experience the lowest surrounding pressure?
Epicardial blood vessels experience the lowest surrounding pressure during the cardiac cycle.
Where is ischemia most likely to occur in the heart?
Ischemia is most likely to occur in the sub-endocardial blood vessels located deep within the left ventricle.
What type of murmur is associated with aortic stenosis?
Aortic stenosis is associated with a systolic murmur.
What is the primary filling problem in mitral stenosis?
The primary filling problem in mitral stenosis is that it causes a filling issue, leading to increased preload and blood volume.
What happens during diastole in aortic regurgitation?
During diastole, backward blood flow occurs due to the leaky valve in aortic regurgitation.
How does mitral regurgitation affect atrial pressure during systole?
Mitral regurgitation causes abnormal volume and pressure in the atria during systole due to backward blood flow.
Fill in the blank: In mitral regurgitation, the backwards blood flow occurs during _______.
[systole]
What is the significance of the atrial kick in heart pathologies?
The atrial kick becomes crucial for filling the ventricle in heart pathologies, especially in conditions like aortic stenosis.
What is eccentric left ventricular hypertrophy?
Eccentric left ventricular hypertrophy is characterized by thin walls of the left ventricle, often associated with congenital dilated cardiomyopathy.
True or False: The pressure build-up in the atria can lead to atrial arrhythmias.
True
What is the consequence of high atrial pressure over time?
High atrial pressure can stretch the atrium, leading to less coordinated contractions and increased risk for arrhythmias.
What treatment can slow congenital dilated cardiomyopathy?
An ACE inhibitor can be used to slow congenital dilated cardiomyopathy.
What happens to the left atrium in severe heart failure?
In severe heart failure, the left atrium can experience pressure and volume build-up, leading to congestion in pulmonary veins.
What is congenital dilated cardiomyopathy?
A heart condition often hereditary, where the heart becomes enlarged and weakened, typically leading to severe outcomes by mid-20s.
ACE inhibitors may slow progression.
What causes aortic valve insufficiency?
Inadequate closure of the aortic valve, causing the left ventricle to fill from two sources instead of one.
Can lead to eccentric or dilated cardiomyopathy.
What is the effect of a myocardial infarction (MI) on the heart?
It causes a patching of the heart tissue, leading to thinner walls in the left ventricle and potential systolic dysfunction.
Results in difficulty pumping blood effectively.
Define systolic dysfunction.
The heart’s inability to generate a normal stroke volume and systemic blood pressure due to thin walls.
Often a consequence of myocardial infarction.
What is concentric cardiomyopathy?
A condition characterized by thicker heart walls, often due to stenotic aortic valve or long-term untreated hypertension.
Leads to diastolic dysfunction due to less compliant walls.
Describe diastolic dysfunction.
A condition where the heart has difficulty filling due to thickened, less compliant walls.
Opposite of systolic dysfunction.
What is ischemia in the context of heart health?
A condition where an area of the heart lacks sufficient blood supply, potentially leading to larger infarcts if collateral circulation fails.
Severity can increase if blood vessels cannot dilate.
What role does collateral circulation play in ischemia?
It provides alternative blood flow to ischemic areas, helping to deliver nutrients and reduce damage.
Dependent on the ability of blood vessels to dilate.
What happens when there is significant ischemia in the heart?
If collateral circulation is inadequate, it can lead to larger areas of infarction and dead heart muscle.
This situation is critical and can result in severe heart damage.
What is the body’s response to dead heart muscle?
The body lays down scar tissue to repair damaged areas, which can lead to further complications if excessive.
Fibroblasts contribute to this process.
How can excessive scar tissue affect heart function?
It can lead to dilated cardiomyopathy by causing the heart to stretch beyond normal limits.
Excessive scar tissue can inhibit proper heart function.
What is the purpose of ACE inhibitors in heart conditions?
They slow the deposition of scar tissue and reduce the activity of growth factors in the heart.
Helps manage excessive scar tissue formation.
What occurs during systole when there is nonfunctional heart muscle?
Outward stretching of the heart wall can occur, leading to a lower ejection fraction (EF).
This indicates poor heart performance.
Patients who have a ____ are at a higher risk of mortality for these two procedures:
Left coronary dominant system; angioplasty and CABG
Why is the did he need to draw the green line?
According to the pressure-volume loop, passive filling in phase I ends at a pressure of about 10-15 mmHg not 20 like the line shows here.
Compliance formula
C = change in volume/change in pressure
How are a childs ventricular walls different from adults? Why?
Their heart walls are less compliant = steeper filling slope (think hypertrophied adult ventricle)
Why do we need to be cautious giving a child a large amount of volume?
They do not have Franks Starling mechanism. The only way they can increase output to accomadate extra fluid is to increase their HR
How would the 4th heart sound be audible?
With mitral or tricuspid stenosis (atrial kick will need to be stronger to get enough blood thru stenotic valve)
What part of the Wiggers diagram could you hear the 3rd heart sound?
During the 2nd and 3rd section of diastole in someone with concentric hypertrophy
What other population of patients would likely have an audible 3rd heart sound?
Young kids
(low compliance ventricles)
A patient with ________ would likely have a reynalds number > 2000
Aortic Stenosis
What is the lower limit of a normal adults hearing ability?
20 hertz
Where would retrograde coronary blood flow most likely happen? Why?
In the Endocardial or subendocardial vessels deep in the wall of the left ventricle.
These will be exposed to the highest pressure during systole
What meds could you give a pt with mitral regurgitation to reduce ____ and help them last longer?
afterload (SVR);
