Lecture 6 - Feb 4 Flashcards
What are the two types of coronary dominance?
- Right coronary dominance
- Left coronary dominance
Right coronary dominance means the posterior descending artery (PDA) is a branch of the right coronary artery. Left coronary dominance means the PDA is a branch of the circumflex portion of the left coronary artery.
What percentage of people typically have right coronary dominance?
Approximately 75% of people
This statistic reflects the common anatomy of coronary arteries.
What is the role of the circumflex artery?
Curves around towards the back of the heart
The circumflex artery branches off the left coronary artery and can supply the PDA in some individuals.
In which situation is left coronary dominance considered a risk factor?
When the left coronary artery is responsible for supplying more heart tissue
This condition increases the risk of serious cardiac issues if the left coronary artery fails.
What happens to pulmonary artery pressure (PAP) during inspiration?
PAP is reduced
This reduction occurs due to the chest becoming more negative, which affects blood flow dynamics.
How does positive pressure ventilation affect cardiac output?
Initially increases, then may decrease
The initial increase in cardiac output occurs due to increased preload; however, prolonged positive pressure can impede venous return.
What is the expected effect of positive pressure ventilation on the right side of the heart?
Preload increases but afterload also increases
This results in a net effect that may not significantly change cardiac output for the right heart.
What structural change occurs in the heart due to aortic stenosis?
Thickening of the heart wall
This adaptation allows for more forceful contractions against a narrowed valve.
What happens to compliance of the ventricle with hypertrophy?
Compliance is reduced
This reduction makes it harder for the ventricle to fill with blood.
What is the relationship between the slope of the passive filling pressure curve and compliance?
A higher slope indicates reduced compliance
This means more pressure is needed to fill the heart with the same volume of blood.
True or False: The left side of the heart is thicker than the right side.
True
This is due to the left side having to pump against higher vascular resistance.
What happens to systemic blood pressure during early inspiration?
It decreases
This decrease is due to low pressure in the pulmonary veins affecting preload.
Fill in the blank: If the circumflex artery supplies the PDA, the patient has _______.
left coronary dominance
What occurs in the thorax when positive pressure ventilation is applied?
Thoracic pressure increases, impeding venous return
This can lead to difficulty in refilling the heart during the next cycle.
What is the effect of increased afterload on the right side of the heart during positive pressure ventilation?
It may negate the benefits of increased preload
This can lead to a situation where cardiac output does not increase significantly.
What is the average filling pressure in the cardiovascular system?
7 mmHg
This pressure is crucial for normal heart filling and cardiac output.
What does the slope of the line in pressure-volume relationships indicate?
The compliance of the systems
Compliance refers to the ability of the system (like the lungs or heart) to stretch and accommodate changes in volume.
How does a highly compliant ventricle behave during filling?
It requires relatively low pressures to fill with blood
A compliant ventricle has thin walls that easily stretch.
What happens to the slope of the pressure-volume loop during aortic stenosis?
The slope of phase one is higher than normal
This indicates that it is harder to fill the ventricle due to thicker walls.
What is the significance of a low compliance ventricle?
It fills faster than normal and reaches fullness quicker
This can lead to the third heart sound being audible.
What are the four possible heart sounds?
- 1st Heart Sound: AV Valves Closing
- 2nd Heart Sound: Aortic Valve Closure
- 3rd Heart Sound: Present in Heart Failure & Pediatric Population
- 4th Heart Sound: Should NOT be present in Healthy People
What causes the first heart sound?
Closure of the AV valves when intraventricular pressure exceeds atrial pressure
This sound lasts approximately 0.14 seconds and is low pitch.
What is the duration of the second heart sound?
0.11 seconds
This sound occurs after the ejection phase.
True or False: The fourth heart sound is audible in healthy individuals.
False
It is typically present when the atria work harder, such as in cases of mitral stenosis.
What is the third heart sound associated with?
Heart failure and low compliance in the ventricle
It indicates turbulence due to poor stretching of the ventricle.
What type of murmur is associated with aortic stenosis?
Systolic murmur
This occurs due to turbulence when blood flows through a narrowed valve.
What type of murmur is produced by aortic regurgitation?
Diastolic murmur
This occurs when blood flows backwards into the ventricle during diastole.
What is a characteristic of mitral stenosis?
It produces a filling murmur that is loudest at the end of diastole
This occurs due to increased atrial contraction needed to fill the ventricle.
Mitral regurgitation results in what type of murmur?
Systolic murmur that is loudest at the beginning of systole
This occurs due to backward flow of blood when ventricular pressure exceeds atrial pressure.
Where is the aortic valve auscultated?
Right side next to the sternum around the 2nd intercostal space
Listening in the direction of blood flow enhances sound clarity.
Where can the pulmonic valve be auscultated?
Left side of the chest close to the sternum in the 2nd intercostal space
Similar to the aortic valve in terms of anatomical location.
Where should you listen for the tricuspid valve?
Medial left side of the patient in the 5th intercostal space
This is the direction of flow through the valve.
How should the mitral valve be auscultated?
In the same intercostal space as the tricuspid valve but further lateral
This aligns with the direction of flow through the valve.
What is the mnemonic to remember the order of valve auscultation?
A, P, T, M (Aortic, Pulmonic, Tricuspid, Mitral)
Variations include phrases like ‘all patients take meds’.
What causes splitting of the second heart sound?
Closure of the aortic valve and the pulmonic valve at different times
This is often influenced by pressure differentials and respiratory cycles.
What is the 2nd heart sound associated with?
Closure of the pulmonary artery valve and the aortic valve
The 2nd heart sound (S2) can sometimes exhibit splitting due to the different pressure differentials on each side of the heart.
What causes the splitting of the 2nd heart sound during deep inspiration?
The pulmonic valve stays open longer due to reduced afterload on the right side of the heart
This results in the pulmonic valve closing after the aortic valve, leading to physiologic splitting of S2.
What instrument is used to record heart sounds and murmurs?
Phonocardiogram
This instrument can detect frequencies lower than what can be heard by the human ear.
What is the superior mediastinum?
The upper section of the mediastinum
It is located above the inferior mediastinum.
List the three parts of the inferior mediastinum.
- Anterior
- Middle
- Posterior
What structures are found in the middle mediastinum?
- Heart
- Pericardium
- Ascending aorta
- Superior vena cava
- Pulmonary arteries and veins
- Pericardiacophrenic nerves
What is the role of the pericardiacophrenic nerves?
Sensory perception in the pericardium and innervation to the diaphragm
What can affect the quality of an arterial line tracing?
Presence of air bubbles or clots
These can dampen the signal, preventing accurate pressure readings.
What is a dicrotic notch?
A feature of an arterial pressure waveform indicating closure of the aortic valve
It is important for calculating heart rate and other cardiovascular metrics.
What is the difference between epicardial and endocardial blood vessels?
- Epicardial vessels are located on the surface of the heart
- Endocardial vessels are located deep within the heart wall
Which blood vessels are most likely to experience ischemia?
Sub-endocardial blood vessels
These vessels are subject to the highest pressure, especially in the left ventricle.
What is aortic stenosis characterized by?
High pressure inside the ventricle to overcome the narrowed valve
This results in significant pressure differentials during systole.
What happens during mitral stenosis?
Filling problem leads to increased preload and blood volume
The atria must generate higher pressure to push blood through the obstructed mitral valve.
What type of murmur is associated with aortic stenosis?
Systolic murmur
What type of murmur is associated with mitral stenosis?
Diastolic murmur
What does a phonocardiogram recording provide?
A high-definition version of what can be heard
Phonocardiograms are used to visualize heart sounds.
What type of murmur is associated with aortic stenosis?
Systolic murmur
Aortic stenosis occurs when the aortic valve narrows, affecting blood flow during heart contractions.
What type of murmur is associated with mitral stenosis?
Diastolic murmur
Mitral stenosis occurs when the mitral valve narrows, affecting blood flow during heart relaxation.
What is a key characteristic of aortic regurgitation?
Wide pulse pressure
Aortic regurgitation involves backflow of blood into the left ventricle during diastole.
During which phase does backward blood flow occur in aortic regurgitation?
Diastole
Backward flow happens when the aortic valve is not fully closed.
What occurs in mitral regurgitation during systole?
Blood leaks backward through the mitral valve
This leakage can cause abnormal volume in the atria during systole.
What happens to atrial pressure in the later stages of mitral regurgitation?
Atrial pressure builds up significantly
Increased volume and pressure in the atria can lead to complications.
What is the effect of reducing afterload in mitral regurgitation?
Reduces backward blood flow through the leaky valve
This can help manage symptoms and prevent further complications.
What role does the atrial kick play in heart pathologies?
Increases filling of the ventricle
The atrial kick becomes more important in conditions like aortic stenosis.
What is the difference between systolic dysfunction and diastolic dysfunction?
Systolic dysfunction is related to reduced contractility, while diastolic dysfunction involves impaired filling
These dysfunctions can occur due to various heart conditions.
What is concentric hypertrophy?
Thickening of the heart walls
It can occur due to long-term hypertension or aortic valve stenosis.
What is eccentric hypertrophy?
Thinning of the heart walls
This condition may be seen in dilated cardiomyopathy or aortic valve insufficiency.
What is the main consequence of myocardial infarction?
Formation of scar tissue
Scar tissue can lead to systolic dysfunction and reduced contractility.
What does ischemia in the heart indicate?
Reduced blood flow to the heart muscle
Ischemia can lead to heart attacks if not resolved.
What happens when collateral circulation fails during ischemia?
Increased risk of a larger area of infarct
The inability of surrounding blood vessels to dilate can worsen tissue damage.
What is the role of scar tissue in heart repair?
Patches damaged areas of the heart
Excessive scar tissue deposition can lead to further complications.
How do ACE inhibitors help in heart conditions?
Slow down scar tissue deposition
They reduce the activity of growth factors that promote scar formation.
What is the risk of prolonged high atrial pressure?
Increased risk of atrial arrhythmias
High pressure can lead to stretching of the atria and loss of coordination.
True or False: Atrial flutter is a coordinated contraction of the atria.
False
Atrial flutter involves rapid and disorganized contractions.
What is the role of fibroblasts in scar tissue deposition?
Fibroblasts are in charge of building stuff.
What is the purpose of a growth factor inhibitor in scar tissue management?
To slow down the rate of scar tissue deposition and reduce the activity of growth factors.
What happens when a portion of the heart wall is nonfunctional during contraction?
It can lead to systolic stretch.
What is expected during systole regarding blood movement?
All the blood should be moving into the aorta.
What effect does a nonfunctional area of the heart wall have during ventricular contraction?
It causes the wall to bow, leading to a much lower ejection fraction (EF).
True or False: During systole, outward stretches should be present.
False.
Fill in the blank: A growth factor inhibitor can help keep excessive _______ deposition in check.
[scar tissue]
