Cardiac cycle and haemodynamics Flashcards
What is the equation for pressure
Pressure = flow X resistance
Describe the PQRST wave in terms of depolarisation
P - depolarisation of SA node (atrial depolarisation)
QRS - ventricular depolarisation
T - relaxation of ventricles
What is diastolic ventricular filling?
when the ventricles are filling
What is isovolumic contraction?
When ventricles have raised pressure, but no ejection cos the valves are closed.
Systolic ejection
blood pumped out
What does haemo-dynamics mean?
Blood-power
State the two equations for power
Force X velocity
Pressure X Flow rate
What is stoke volume?
Stroke volume is the amount of blood ejected by the left ventricle in one contraction.
State the equation for stroke volume
(End-diastolic volume) - (End - systolic volume)
State the equation for ejection fraction (LVEF)
LVEF is just the fraction of blood that is pumped out. So percentage.
LVEF = SV/EDV
State the equation for cardiac ouput
Cardiac output = heart rate X stroke volume
What is the primary function of the heart as a pump?
To convert chemical energy (atp) into hydraulic energy in order to maintain a physiological circulation
What is aortic stenosis?
narrowing of the aortic valve
