BF/Hemodynamics, Cardiac Cycle Flashcards
COP=
SV*HR
relationship between BP and flow
Q=P drop/R
relationship between BP and TPR
P drop=CO*TPR
fx contrib to resistance
R=8nl/(pi)r^4
fx contrib to flow
Q=pressure drop(pi)r^4/8nl
MAP
MAP=DBP+(1/3)(SBP-DBP)
pulse pressure
SP-DP
velocity and total cross sectional area
velocity dec with inc total cross sectional area
How do capillaries withstand high P?
T=Pr (law of LaPlace)
Small vessels can withstand high P bc their radii are small – can maintain T (force needed to prevent wall from splitting)
Swan-Ganz catheter
vein–> RA –> RV –> pulm A –> wedges into small vessel –> detects pulm wedge P (good indicator of LA P)
ventricular systole begins when the ____ valve closes and ends when the ____ valve closes
mitral, aortic
a wave
atrial systole
c wave
atrial contraction
x descent
atrial relaXation
v wave
venous filling
y descent
atrial emptying
obtaining the SV from pressure-volume loop
WIDTH of the pressure-volume loop is the difference between EDV and ESV (=SV)
area within the pressure-volume loop
ventricular stroke work (work done by ventricle to eject a vol of blood into the aorta)
ESPVR curve
filling of the ventricle
gives the maximal pressure that can be developed under any given LV volume
duration of systole vs diastole
duration of systole is ~1/3 cardiac cycle, while diastole is ~2/3
systemic vs pulm BF
EQUAL although SVs can vary from beat to beat
SV at rest
~70 ml
EF=
SV/EDV
~55%
events occurring almost simultaneously with onset of systole
- QRS complex
- S1
- c wave
- closure of mitral valve
- rise in ventricular P
events occurring almost simultaneously with onset of diastole
- S2
- closure of aortic valve
- incisura
- drop in ventricular P
the heart pumps its stroke volume between
S1 and S2
