Work of the heart Flashcards
1
Q
What is CO?
A
Cardiac output - litre of blood pumped per unit of time
2
Q
What factors affect CO?
A
HR and SV
3
Q
What factors affect HR?
A
Autonomic innervation
Hormones
Fitness levels
Age
4
Q
What factors affect SV?
A
Heart size Fitness levels Gender Contractility Duration of contraction Pre-load After-load
5
Q
What is pre-load?
A
The EDV that stretches the ventricles to the maximum
6
Q
What is after-load?
A
The pressure the heart must work at to eject blood. Pressure at ESV
7
Q
Other than work output what is the energy of the heart converted to?
A
Heat
8
Q
What phase is categorised by after-load?
A
End of ventricular systole
9
Q
What phase is categorised by pre-load?
A
End of atrial systole (EDV)
