B5 - Heart Problems and Repairs Flashcards
Why might a person need an artificial pacemaker?
If they have an irregular heartbeat.
Some people have a damaged AVN. Its impulses do not travel to the ventricles. In this case the artificial pacemaker wire goes to the ventricle and makes it contract.
How is an artificial pacemaker implanted?
It is usually implanted just under the skin in the chest. A wire passes from it into a vein and into the right atrium.
How do artificial pacemakers work?
It has a long-life battery. It sends impulses to the heart muscle, to make it contract at the correct rhythm. A pacemaker can detect when the person is more active, and sends impulses to the heart at an increased rate.
How often do artificial pacemakers have to be replaced?
About every ten years
How do fetuses get oxygen?
Fetuses have a small hole between the left and right atria. They obtain oxygen from the placenta. Oxygenated blood enters the right side of the heart and flows through the hole to the left atrium, and then to the head and body. There is a connecting vessel between the pulmonary artery and the aorta, so most blood bypasses the lungs.
Why are some people born with a hole in the heart? What are the results of this condition?
At birth, the baby needs to oxygenate its blood via the lungs rather than the placenta. The hole closes and the blood follows the normal circulation.
In some babies, the hole does not close, allowing oxygenated blood to flow from the left to the right atrium. This means that a smaller amount of oxygenated blood leaves the left ventricle, and the body tissues receive less oxygen.
What are the results of a hole in the heart? How is it repaired?
Patients suffer fatigue and breathlessness. The right side of the heart has to work harder to cope with the increased flow of blood through it.
A hole in the heart can be repaired with surgery.
What happens to valves as people get older? What are the results of this?
As people age, their heart valves may become stiff. Valves may also be damaged, such as by bacterial infection (endocarditis). If the valves in the heart do not close properly, blood will flow backwards.
What are the results of faulty valves?
This leads to heart failure, and not enough oxygenated blood can reach body tissues.
How are faulty valves repaired?
Surgeons can replace faulty heart valves with artificial valves or valves from pigs or cows. Because the heart valves have no capillaries supplying them, there is no rejection of these transplanted valves.
Why do some people get blocked coronary arteries?
As you get older, and especially if you eat too much saturated fat and smoke tobacco, fatty deposits or plaques build up in your artery walls. These can become quite large and obstruct the flow of blood.
What are the results of blocked coronary arteries?
Your heart muscle does not get enough oxygenated blood. Heart muscle cells cannot respire anaerobically, and without enough oxygen they cannot release enough energy to contract ef ciently. You may develop angina, or have a heart attack.
How are blocked coronary arteries fixed?
Surgeons can correct this condition with bypass surgery. A piece of blood vessel, usually a vein, is taken from the patient’s arm or leg and transplanted to bypass the blockage (or blockages) in the coronary artery.
How are heart attacks fixed?
When people have had a heart attack, surgeons can quickly insert a stent, a tube to open up the blocked coronary arteries. If this is done soon enough, the damage to the heart from the heart attack is slight.
What are the risks with all the different heart procedures?
A heart transplant is a traumatic operation and the recipient must take drugs to suppress the immune system and prevent rejection. There is a shortage of donor hearts.
Heart valve replacement and artificial pacemakers are less traumatic with no risk of rejection, but pacemakers have to be replaced.
All operations carry the risk of infection.
