cardio definitions and equations Flashcards
what is preload?
the load present before left ventricular contraction starts
what is afterload?
the load present after the ventricle has started to contract
what is contractility?
the state of the heart which enables it to increases its contraction velocity, to achieve higher pressure, when contractility is increased (independent of load)
what is compliance?
the relationship between the change in stress and resultant strain
what is resistance?
vascular resistance to the flow of blood in the peripheral arterial vessels that is typically a function of the internal vessel diameter, vessel length and blood viscosity
what is the equation for stroke volume?
end diastolic volume- end systolic volume
what is the equation for mean arterial pressure?
diastolic pressure + 1/3 pulse pressure
what is the equation for cardiac output?
heart rate x stroke volume
what is the equation relating ohms law to vessel resistance?
flow= pressure gradient / resistance
what is Poisuille’s (or however you spell it) law?
change in pressure is proportional to the radius to the power of 4
what is the equation for pulse pressure?
systolic pressure- diastolic pressure
what is elasticity?
the myocardial ability of the heart to recover its normal shape after removal of systolic stress
what is the left ventricular filling pressure?
difference between left atrial pressure and left ventricular diastolic pressure
what is the equation for approximate mean arterial pressure?
diastolic pressure + 1/3 (systolic- diastolic pressure)
what is the equation for cardiac output?
heart rate x stroke volume
