Cardiac Lecture 6 Flashcards
What percent of people have a PDA that branches off the RCA aka right coronary dominance?
75%
What percent of people have a PDA that branches off the LCA aka left coronary dominance?
15%
Is it a higher risk for the PDA to descend from the RCA or LCA?
LCA
Positive pressure ventilation would result in a _______ filling pressure and _______ CO
higher filling pressure- need more volume and/or venous constriction
Higher CO initially, but with prolonged positive pressure ventilation will result in lower CO
Aortic stenosis would result in what change to the heart walls? What is the downside?
hypertrophy, thick heart wall - harder to fill ventricles (reduced compliance) need to inc Psf to accommodate
- inc slope of phase I
Dilated cardiomyopathy (aortic valve regurgitation) would result in what change to the heart walls?
stretched out ventricle, thinner heart wall - high compliance, dec Psf
- dec slope of phase I
How are kid ventricles different from adults?
less compliant ventricle - can’t accommodate inc venous return so have to inc HR instead
- be careful with volume
What causes the first heart sound?
AV valves closing (ventricular pressure > atrial) vibration, systole
Which heart sound is the longest? What is the pitch?
1st (0.14 s) - low pitch
How long is the second heart sound? Pitch?
0.11 sec, higher pitch
What is the cause of the 2nd heart sound? What is unique about S2?
pulmonary and aortic valves closing, diastole
- can have splitting during deep inspiration and pulmonic valve stays open longer and closes after aortic valve
When is the 4th heart sound heard?
when the atrium is doing more work/fuller than normal (mitral stenosis) - unhealthy heart
When can the 3rd heart sound be heard?
kids and heart failure - low compliance ventricle; walls not stretching enough - turbulence
What heart sounds are expected in aortic stenosis?
loud murmur during systole
What heart sounds are expected in mitral stenosis?
murmur during diastole, loudest at the end (atrial contraction)
What heart sounds are expected in aortic regurgitation?
murmur during diastole - loudest in the beginning and dec
What heart sounds are expected in mitral regurgitation?
backward flow during systole - systolic murmur loudest at the beginning
Where can valves be auscultated?
aortic valve - R 2nd ICS
pulmonic valve - L 2nd ICS
tricuspid - L 5th ICS
bicuspid - lateral L 5th ICS
What is the acronym for valve auscultation?
APTM - all physicians take money
What instrument is used to identify heart murmur frequencies that are too low to hear?
Phonocardiogram
How low can the ear hear?
20 Hz
What are the divisions of the mediastinum?
Superior
Inferior:
- Anterior
- Middle
- Posterior
What do the pericardiacophrenic nerves sense?
responsible for sensory perception in the pericardium and diaphragm
What is included in the posterior mediastinum?
esophagus, thoracic aorta and ducts, vagus nerves, azygos and hemizygous veins
