Lecture 24 - Ventricular Function

Question 1

Ventricular Diastole?

Answer 1

closure of semilunar valves, ventricle pressure drops below arterial, isovolumic relaxation, rapid ventricular filling from AV valve opening, slow filling (diastasis), atrial systole to finish

Question 2

Ventricular P-V relationship?

Answer 2

curved, small pressure change up to certain volume

Question 3

Phases of LV pressure volume loop?

Answer 3

passive ventricular filling - diastole (a), isovolumetric contraction - systole (b), ejection - end of systole (c), isovolumetric relaxation - diastole (d)

Question 4

Determinants of ventricular performance?

Answer 4

preload (degree of filling), afterload (pressure which ventricle contracts and valves open), ionotropic state (contractility), heart rate (contractions/min)

Question 5

Determiannts of afterload pressure?

Answer 5

systolic LV and aortic pressure, fibre tension

Question 6

Adjusted Inotropic state?

Answer 6

adjusts max active tension, shifts E-S P-V relation

Question 7

Balancing L and R?

Answer 7

inc MAP -> dec SV -> blood accumulate in lungs -> inc EDV (preload) -> inc SV

Question 8

Stroke work equal to?

Answer 8

integral of pressure (pressure not constant - AP for estimate) x change in volume (SV)