Intro to Wigger and PV Loops Flashcards
why are ventricular and aortic pressures are similar in systole but different in diastole?
because the aortic valve “holds” pressure in the aorta, so blood passively flows in a forward direction.
what happens if ventricular diastolic pressure is too high?
- usually it neesd to be low so that the ventricle can fill from atrial blood
- in disease states when the pressure increases, blood cannot flow from atria to ventricle, causing congestive heart failure.
in the right atrium:
a; when the atrium contracts, the pressure will go up
c; when the ventricle first contracts, the tricuspid valve will close, bulding upward into the atrium and the P will go up.
v: throughout ventricular contraction, the tricuspid valve is closed, but the atrium is filling from blood returning from the body.
recall: The tricuspid valve forms the boundary between the right ventricle and the right atrium.
when the ventricular diastolic pressures are elevated, the JVP will be ____
when the ventricular diastolic pressures are elevated, the JVP will be elevated
stroke volume equals:
end diastolic volume (vol after filled)- end systolic volume (vol remaining after ejection)
S3 and S4 are abnormal heart sounds. What causes them?
S3= rapid overfilling of the ventricle, usually occurs in the heart failure.
S4= atrial contraction plus a stiff ventricle.
outline point a to b in a PV loop
A: start of diastole
B: end of diastole. volume increases a lot, and pressure goes up a bit too. Point B is preload. point B is the LEFT VENTRICULAR DIASTOLIC VOLUME.
outline point b to c in a PV loop
B to c is isovolumetric contraction of the ventricle. C represents afterload
outline C to d point in a PV loop
C to D is ejection. D point is end systolic volume. C-D is stroke volume.
this section will determine storke volume and ESV. If it’s weak, it will move D over to the right– there will be more ESV. The overall stroke volume will be thus decreased.
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