Cardiac Pathophysiology

Question 0

What are the four determinants of myocardial demand ?

Answer 0

HR
Contractile force
Muscle mass
Ventricular wall tension
Notes: if heart beat speed up or the force of contractions become stronger, cardiac workload and oxygen demand increase.
This can occur in hypertension, ventricular dilation, or heart muscle hypertrophy or as the result of the action of some medications

Question 1

A decrease in oxygen supply or an increase in the heart muscle’s oxygen demand can…………….

Answer 1

Disturb this balance and threaten myocardial function.

Question 2

Regurgitation (回流）？

Answer 2

A diseased valve allows blood to flow backward across leaflets that haven’t close securely. ( back blood flow force the heart to pump more blood, increase cardiac workload)!

Question 3

Stenosis (狭窄）？

Answer 3

The valve opening may also become restricted by calcium build up and impede (阻碍）the forward flow of blood.