- The first heart transplant was performed in South Africa in 1967 by Dr. Christiaan Barnard. The patient lived 18 days.
- In 1980, 80% of patients survive a year after a heart transplant.
- Robert Jarvik made the first artificial heart in 1982.
- Barney Clark, a retired dentist, was the first person to receive an artificial heart.
- Today, surgeries used to correct congenital heart disorders have about a 95% success rate.
- To make heart surgery as minimally invasive as possible, we can use surgeon-operated robots to make small incisions
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Heart Patient Case History: Baby Fae
Stephanie Fae Beauclair, more commonly known as Baby Fae, was the first infant to receive a non-human heart transplant procedure. She was born three months prematurely, and was only two weeks when the surgery was performed. Baby Fae was born in 1984 with hypoplastic left-heart syndrome, a fatal condition in which the left side of the heart, the side that pumps oxygenated blood throughout the body, is severely undeveloped. Knowing that this was a life-or-death situation (most children with this disorder die within two weeks), Fae's doctor, Dr. Leonard Bailey, frantically searched for an infant donor heart. However, there was no way he could find one in time to save Fae. In an act of desperation, Bailey examined prior research about cross-species transplants and found that perhaps a baboon heart would be his last hope. Fae would be the perfect opportunity to carry out his experiment on a human. After 20 hours of contemplation, Fae's parents finally agreed to let Dr. Bailey try his procedure.
A considerable amount of tests had to be performed to figure out which baboon heart would be a match for Fae's, and there was no time to waste. Eventually, a donor was chosen. However, a major difference between human and baboon hearts is that human hearts have three major arteries that extend from the aortic arch; baboons only have two. To combat this, Dr. Bailey joined two of Fae's arteries together. Then, he connected her to a heart-lung machine to lower her body temperature, slow her metabolism, and allow her blood to continue pumping. Any transplant procedure is tricky, because the intricate wiring of blood vessels has to be disconnected and then reconnected again. And even if the surgeon is able to reconfigure the vascular pathways, there is still a chance that the patient's immune system will reject the foreign tissue. Dr. Bailey used cyclosporine, a drug that suppresses the immune system without taking away its ability to fight infection, which helped Fae accept the heart. Once the heart began beating on its own, both the medical community and the general public were astonished by the miracle and potentially life-altering decision Dr. Bailey had performed on Baby Fae.
The controversy came quickly. Some experts questioned whether Bailey's intentions were pure, and if he was just using Baby Fae and her family to perform medical experiments. Religious individuals were outraged that a Christian doctor would try to undermine God's creation, and animal lovers wre equally upset at the slaughter of a baboon for her heart. However, as the days passed, slowly more faith was shown towards the work of Dr. Bailey as Fae became independent from oxygen masks and intravenous fluids. Unfortunately, after two weeks, signs of rejection were becoming apparent. The most traumatic incident was when Fae's kidneys started to fail. Fae died three weeks after her surgery, but the impact she has had on heart transplant research was enormous. Perhaps one day a human with a simian heart will be capable of sustaining life.
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Heart Beats and Electrocardiograms (EKG):
When the heart is at rest, blood flows into the atria. The right side collects oxygen-poor blood while the left side collects oxygen-rich blood. Clusters of cells called the sinoatrial node send out electrical impulses to make the atria contract, thus forcing blood into the ventricles. Then, the atrioventricular node is triggered, causing the ventricles to contract. This phase is called systole. This releases blood from the right ventricle to the lungs, and from the left ventricle to the rest of the body. The blood pushes against mitral valve on the left and tricuspid valve on the right, which shuts them closed to prevent blood from flowing backwards. This makes the "lub" sound of a heartbeat. The ventricle relax in diastole, causing the pulmonic and aortic valves to shut. This sound is known as "dub."
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Every time the heart beats, tiny electrical impulses are discharged. Using a process called electrocardiography, those electrical discharges can be recorded and used to measure the heart's condition. Several thin wires are attached to the body. The wires conduct the electrical charges into a machine that measures them and produces a readout that can be interpreted as a series of waves, defined as follows:
P wave - sinoatrial node fires electrical impulses to make the atria contract
QRS complex - atrioventricular node fires electrical impules to make the ventricles contract
T wave - ventricles relax
Types of Heart Surgeries:
Coronary bypass - A healthy blood vessel is removed from another part of the body, such as the leg or chest wall. Surgeons then build a shortcut around a blocked coronary artery. One end of the vessel is attached below the blocked vessel, while the other end is grafted right above it. If it is successful, then blood flow can continue without interruption. Multiple grafts can be built in one surgery, potentially leading to double, triple and even quadruple bypasses.
Heart transplant - A diseased heart is removed from a patient, and then the healthy donor heart is attached. The operation is complicated because so many blood vessels have to be detached and re-attached. After the operation, there is still a risk that the patient's systems may reject the new heart. Tissue types have to be perfectly matched in order for the transplant to be successful. As a result, the number of transplants performed is quite low.
Angiocardiography - Doctors can find where an artery is blocked through coronary arteriography. This means that the coronary arteries are mapped using a procedure called cardiac catheterization. The doctor uses a catheter (a thin plastic tube) and moves it through an artery in the arm or leg and traces it into the coronary arteries. A liquid dye is poured through the catether, and when exposed in an x-ray, the liquid appears white. If there are dark sections of the x-ray of arteries, then the doctor knows that the dye did not pass through, so something must be blocked. Angiocardiography is especially suited for determining the extent and location of coronary artery disease.
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