More on cardiovascular disease Flashcards
If a patient has heart failure, what may doctors perform ?
a heart transplant using organ doners from people who have recently died. However, if donor organs aren’t available right away or there not the best option . Doctors might fit an artificial heart.
What are artificial hearts ?
mechanical devices that pump blood for a person whose own heart has failed. They’re usually only used as a temporary fix, to keep a person alive until a donor heart can be found or to help a person recover by allowing the heart to rest and heal. In some cases though they’re used as a permanent fix, which reduces the need for a donor heart
Advantages of artificial hearts
they’re less likely to be rejected by the body’s immune system than a donor heart. This is because they’re made from metals or plastics, so the body doesn’t recognise them as ‘ foreign’ and attack them in the same way as it does with living tissue
disvantages of artificial hearts
Surgery to fit an artificial heart can lead to bleeding and infection
artificial hearts don’t work as well as naturally healthy hearts, parts of the heart could wear out or the electrical motor could fail. Blood doesn’t flow through artificial hearts as smoothly, which can cause blood clots and lead to strokes. The patients has to take drugs to thin their blood and make sure this doesn’t happen, which can cause problems with bleeding if they’re hurt in an accident.
The valves in the heart can be —— or ——- by what ?
damaged, weakened
by heart attacks, infection or old age.
The damage may cause the valve tissue to stiffen so it won’t open properly. Or a valve may become leaky, allowing blood to flow in both directions rather than forward. This means that blood doesn’t circulate as effectively as normal.
How can severe valve damage be treated ?
by replacing the valve. Replacement valves can be ones taken from humans or other mammals ( cows) - These are biological valves or they can be man made = mechanical valves
Replacing a valve is much less drastic procedure than a whole heart transplant than a whole heart transplant. But fitting artificial valves is still major surgery and there can still be problems with blood clots.
How long can a heart still pump RBC ?
When someone loses a lot of blood, e.g. in a car accident, their heart can still pump the remaining RBC around as long as the volume of their blood can be topped up.
What is artificial blood substitutes ?
e.g. salt solution saline which is used to replace the lost volume of blood. It’s safe and can keep people alive even if they lose 2/3 of their RBC. This may give the patient enough time to produce new RBC if not, the patients will need a blood transfusion.
Ideally, an artificial blood product would replace the function of the lost RBC, so that there’s no need for a blood transfusion. Scientists are currently working on products that can do this.
