Lecture 6 Flashcards
Exam 1 content
What is right coronary dominance?
PDA branches from the RCA
What is left coronary dominance?
PDA branches from the circumflex
% of population that is right coronary dominant and % left coronary dominant
right: 75%
left: 15%
The rest of the population has a branch off both
Which form of coronary dominance is more dangerous? why?
left coronary dominance is more dangerous because more of the heart muscle relies on one vessel (less collateral flow). Left coronary dominance makes angioplasties and CABG much more risky
What do you expect to see with positive pressure breathing relative to CO?
you are increasing pressure in the thorax which increases preload and CO at first.
What does positive pressure ventilation do to venous return?
decreases VR (increased PAP and increased afterload on the right heart).
When does the heart fill with blood during positive pressure ventilation?
during expiration to just before the next inspiration (positive pressure)
What causes pathologic left ventricular hypertrophy (less compliant)?
aortic stenosis, chronic hypertension. Kiddos also have less compliant left ventricles.
What causes dilated left ventricular cardiomyopathy (stretched out, very compliant)?
aortic valve regurgitation
What is eccentric LV hypertrophy?
dilated LV (thin walls)
What is concentric LV hypertrophy?
increased wall thickness in LV
What causes the first heart sound? How long does it last?
AV valves close. It lasts 0.14 sec. Low pitched.
What causes the second heart sound? How long does it last?
Aortic valve closing. It lasts 0.11 sec. and is higher pitched.
What is the fourth heart sound?
“atrial kick” shouldn’t hear this in healthy people, but you could hear it with mitral stenosis.
What is the third heart sound?
You can hear this with a low compliance ventricle (kids, aortic stenosis).
With what pathology would you hear a systolic murmur?
aortic stenosis, mitral regurgitation and anemia
How could you differentiate a systolic murmur caused by aortic stenosis versus mitral regurgitation?
The systolic murmur will be loudest at the beginning of systole and tails off at the end of systole for mitral regurgitation. The murmur associated with aortic stenosis will be loudest period d/t tons of turbulence
When would you hear a diastolic murmur?
aortic regurgitation, mitral stenosis
How could you differentiate a diastolic murmur caused by aortic regurgitation versus mitral stenosis?
the diastolic murmur associated with mitral stenosis is much louder at the end of diastole. Aortic regurg would be loudest at the beginning of diastole.
Where can you auscultate the aortic valve?
R side of sternum 2nd ICS. Or the right side of the neck.
Where can you auscultate the pulmonic valve?
L side of sternum 2nd ICS.
Where can you auscultate the tricuspid valve?
medial left side of the patient in the 5th ICS.
Where can you auscultate the mitral valve?
lateral left side of the patient in the 5th ICS.
What is the pneumonic we learned to remember the order to auscultate the 4 different heart valves?
“All Patients Take Meds”
What causes splitting of the second heart sound/ S2?
on deep inspiration the left and right heart afterload differentials become more exaggerated so you can hear two sounds with S2. This is the closure of the aortic valve and then the closure of the pulmonic valve.
List a few structures found in the middle mediastinum…
heart
pericardium
ascending aorta
superior vena cava
pulmonary veins and trunk
pericardiacophrenic nerves
what nerves are responsible for pericardial friction pain from pericarditis?
pericardiacophrenic nerves
List a few structures found in the posterior mediastinum…
esophagus
thoracic aorta
vagus nerves
azygos vein
hemizygos vein
thoracic ducts
If you had an air bubble in your arterial line what would happen to the tracing?
It would be overdamped
give two examples of epicardial coronary arteries…
LAD, PDA
which blood vessels are most likely to experience retrograde blood flow from the start of systole?
the subendocardial blood vessels
What would you give to treat someone with mitral regurgitation to prevent hypertrophy?
an afterload reducer
What is a risk of untreated mitral regurgitation? What could you give to prevent this?
mitral regurgitation could cause dilation of the atria. Stretched atria can become uncoordinated leading to atrial arrhythmias. You can given an afterload reducer.
What could happen as a result of unchecked mitral regurgitation?
increased pressure in the left atrium leading to pulmonary hypertension and pulmonary edema
What are a few things that can cause systolic dysfunction (eccentric LVH)?
congenital cardiomyopathy, aortic valve insufficiency, an MI
What are a few things that can cause diastolic dysfunction (concentric LVH)?
aortic stenosis, long-term untreated hypertension
what is the number one cause of most pathologies r/t ischemia?
vessels that are unable to dilate (less compliance)
What havoc can scar tissue reek on the heart?
fibroblasts lay down scar tissue, but they go above and beyond the dead tissue they are trying to repair leading to hypertrophy
How do ACE inhibitors slow down cardiac remodeling?
they inhibit the growth factors of the fibroblasts to keep excessive scar tissue deposition in check
Why does anemia cause systolic murmurs?
The blood is less viscous which increases turbulent flow causing a systolic murmur. CO will decrease with valvular disease but it will actually increase with anemia.
