Cardiovascular Physiology Topics Flashcards
how do you calculate cardiac output?
you multiply HR by SV
what does a positive chronotropic effect have on the heart?
increases heart rate
what effect does increased heart rate have on contractility?
increased heart rate increases contractility–> positive staircase effect and post-extrasystolic potentiation
what is the positive staircase effect?
when heart rate doubles, the tension developed on each beat increases in a stepwise fashion
what is post-extrasystolic potentiation?
when an extrasystole occurs, the tension developed on the next beat is greater than normal
What are the two types of heart failure?
systolic dysfunction and diastolic dysfunction
what is systolic dysfunction?
when the heart has trouble contracting and pumping blood out
what is diastolic dysfunction?
when the heart won’t fill properly
In a heart failure patient what would you expect the CO and the atrial pressure to look like?
decreased cardiac output and increased atrial pressure
how would you describe the EF of systolic HF?
HRrEF (reduced EF)
how would you describe the EF of diastolic HF?
HRpEF (preserved EF)
what is the systolic pressure curve (ESPVR) associated with?
contractility
what is the diastolic pressure curve (EDPVR) associated with?
relaxation/filling
what could increased preload be caused from?
more venous return, more blood volume, and venous constriction
what is the effect of an increased preload on EDV, afterload, and contractility?
increased preload causes a greater EDV, but afterload and contractility remain the same
what effect does increased preload have on stroke volume?
increased preload causes an increased stroke volume
what is preload?
the volume of blood in the ventricles at the end of diastole
what is preload synonymous with?
the end diastolic volume
what conditions cause increased preload?
hypervolemia, regurgitation of cardiac valves, and heart failure
what is afterload?
the resistance the left ventricle must overcome in order to circulate blood
when might afterload be increased?
hypertension, vasoconstriction, and aortic stenosis
what effect does increased afterload have on preload and contractility?
they remain unchanged
What effect does increased afterload have on SV and EF?
there will be a reduced SV and EF in cases of increased afterload
What happens to the velocity of contraction as afterload increases?
velocity will decrease has afterload increases
when is velocity of contraction of the LV the greatest (in regards to afterload)?
when afterload is 0
What is the effect of increased contractility on SV, EF, preload, and afterload?
there will be an increase in SV, and an increase in EF; there will not be any change to preload or afterload
when preload is changed, after a few beats, what happens? compensatory
there will be a corresponding change to afterload
what is the effect of increased preload on afterload? compensatory
increased preload will cause an increase in afterload
when there is a change in afterload, after a few beats, what happens? compensatory
there will be a corresponding change to preload
what is the effect of increased afterload on preload? compensatory
increased afterload will eventually cause increased preload as stroke volume is decreased
when there is a change in inotropy (contractility), what are the corresponding changes? compensatory
there will be changes in preload and afterload
what is the effect of increased contractility on preload and afterload? compensatory
increased contractility will cause decreased preload and increased afterload
