Heart attacks
The heart is a muscular organ in most animals, which transports blood through the blood vessels of the circulatory system. Blood provides the body with oxygen and nutrients, as well as assists in the removal of metabolic wastes. In humans, the heart is located between the lungs, in the middle compartment of the chest.
This research report is going to be exploring heart attacks, the problem it brings upon humans and how scientists are trying to solve the issue of heart attacks. A heart attack happens when there is a sudden complete blockage of an artery that supplies blood to an area of your heart. (Heartfoundation)
Coronary circulation
The heart muscle, like every other organ or tissue in your body, needs oxygen-rich blood to survive. Blood is supplied to the heart by its own vascular system, called coronary circulation. The aorta branches off into two main coronary blood vessels. These coronary arteries branch off into smaller arteries, which supply oxygen-rich blood to the entire heart muscle. The right coronary artery supplies blood mainly to the right side of the heart. The right side of the heart is smaller because it pumps blood only to the lungs. The left coronary artery, which branches into the left anterior descending artery and the circumflex artery, supplies blood to the left side of the heart. The left side of the heart is larger and more muscular because it pumps blood to the rest of the body.
Problem
The chance of having a heart attack increases significantly as humans age. As humans get older, the inner walls of the arteries that transport blood to the heart can become impaired and narrow due to the build-up of fatty materials, called plaque. When an area of plaque ruptures in an artery, blood cells and other parts of the blood stick to the damaged area as they try to pass through to the heart, as the blood builds up it will eventually form blood
clots. A heart attack occurs when a blood clot completely blocks the flow of blood and genuinely reduces blood flow to the heart muscle. Because of this, parts of the heart start to deteriorate and the longer it is left untreated the worse the damage is. If blood flow is not restored quickly, the damage caused to the heart is permanent. There are many methods to lower the chance of they are: angioplasty and stent implantation, coronary bypass surgery or an implantable cardioverter defibrillator.
From this graph it can be seen that with technological advances in medicine that survival rates after having some type of surgery on the heart have increased significantly overtime.
Coronary bypass surgery
A coronary bypass surgery will usually happen when a patient has an artery blockage for which angioplasty isn't appropriate, the patient may have had a previous angioplasty or stent placement that hasn't been successful, or the patient had stent placement, but the artery has narrowed again (restenosis).
A coronary bypass surgery is a surgical procedure that diverts the flow of blood around a section of a blocked or partially blocked artery in your heart. By creating a new pathway to the heart, coronary bypass surgery improves blood flow to your heart muscle. (mayoclinic staff)
The procedure of having a coronary bypass surgery will happen if the patient is feeling symptoms such as:
• The patient has severe chest pain caused by narrowing of several of the arteries that supply the heart muscle, leaving the muscle short of blood during even light exercise or at rest.
• You have more than one diseased coronary artery and the heart's main pumping chamber and the left ventricle isn't functioning well.
• Your left main coronary artery is severely narrowed or blocked. This artery supplies most of the blood to the left ventricle.
The method for a coronary bypass surgery is:
1. The surgeon starts by making an incision in the middle of your chest. Your rib cage is then spread apart to expose your heart.
2. You are then hooked up to a cardiopulmonary bypass machine which circulates oxygenated blood through your
body while your surgeon operates on your heart.
3. Blood is pumped out of your heart by the machine to remove carbon dioxide, and the machine is then filled with oxygen. The oxygenated blood is pumped back into your body without going through the heart and lungs. This keeps oxygenated blood pumping throughout your body.
4. The surgeon will also use cooling techniques to bring your body temperature down to around 18°C. This technique suspends your body’s processes and makes long heart surgeries possible.
5. Cooling techniques allow the surgeon to operate on your heart tissue for a few hours at a time. These techniques decrease the risk of heart damage or brain damage from a lack of oxygen.
6. The surgeon then removes a healthy blood vessel from inside your chest wall or leg to replace the blocked or damaged portion of your artery. One end of the graft is attached above the blockage and the other end below. (Healthline staff)
Risks of having a coronary bypass surgery are:
Heart attack
Stroke
Bleeding during or after the surgery
A change in kidney function
A lung infection
Changes in your heart rhythm
An allergic reaction to the anaesthesia or other materials used during the surgery
Injuries to your nerves in your chest, arms, or legs
Memory loss
Benefits of having this procedure is having less chest pain or having it go away, minimalizing the risk of having another heart attack and having more energy for physical activities as your body can transport oxygenated blood to cells that need respiration more efficiently.
This method is an effective way of keeping patients safe from having heart attacks when coronary blockages have been found but a key risk of having the surgery is memory loss for the patient and having a lung infection from your organs being open while surgery is taking place, this can lead to more intense surgeries for the patient, so it is vital that the tools are sterilised and the room is clean.
Angioplasty and stent implantation
Angioplasty is a method to open narrowed or blocked blood vessels that supply blood to the heart. These blood vessels are called coronary arteries. A coronary artery stent is a small, metal mesh tube that expands inside a coronary artery. A stent is often placed during or immediately after angioplasty.
The method to complete an angioplasty and stent implantation is:
1. Before the angioplasty procedure begins, you will receive some pain medicine. You may also be given medicine that relaxes you, and blood-thinning medicines to prevent a blood clot from forming.
2. You will lie on a padded table. Your doctor will insert a flexible tube (catheter) through a surgical cut into an artery. Sometimes the catheter will be placed in your arm or wrist, or in your groin area. You will be awake during the procedure.
3. The doctor will use live x-ray pictures to carefully guide the catheter up into your heart and arteries.
4. Dye will be injected into your body to highlight blood flow through the arteries. This helps the doctor see any blockages in the blood vessels that lead to your heart.
5. A guide wire is moved into and across the blockage. A balloon catheter is pushed over the guide wire and into the blockage.
6. The balloon on the end is inflated. This opens the blocked vessel and restores proper blood flow to the heart.
7. A wire mesh tube (stent) may then be placed in this blocked area. The stent is inserted along with the balloon catheter. It expands when the balloon is inflated. The stent is left there to help keep the artery open. (medlineplus.gov)
Risks that can occur from having this surgery are
Allergic reaction to the drug used in a drug-eluting stent, the stent material, or the x-ray dye
Bleeding or clotting in the area where the catheter was inserted
Blood clot
Clogging of the inside of the stent (in-stent restenosis)
Damage to a heart valve or blood vessel
Heart attack
Kidney failure
Irregular heartbeat
Stroke
Benefits of having an angioplasty and stent implantation is an effective way to get blood flowing to the heart again speedily. The sooner your doctor restores your blood supply, the less damage there will be to your heart muscle. Angioplasty also relieves chest pain and may prevent shortness of breath and other symptoms associated with a heart attack. Angioplasty may also cut the odds that you could need more invasive open-heart bypass surgery, which requires a significantly longer recovery time. The National Health Service notes that angioplasty may lower the risk of having another heart attack. It may also increase your chances of survival more than medications that break up blood clots.
This method is very effective as it doesn’t take too long to complete, and it is an efficient way get blood flow happening again. A big risk of having this surgery is having an irregular heartbeat because this can result in the patient getting an ICD.
Implantable cardioverter defibrillator (ICD)
An ICD is a battery-powered device placed under the skin that keeps track of your heart rate. Thin wires connect the ICD to your heart. If an abnormal heart rhythm is detected the device will deliver an electric shock to restore a normal heartbeat if your heart is beating chaotically and much too fast.
The process to get an ICD inserted is to;
1. The doctor will make a small incision at the insertion site.
2. A sheath, or introducer, is inserted into a blood vessel, usually under the collarbone. The sheath is a plastic tube through which the ICD lead wire will be inserted into the blood vessel and advanced into the heart.
3. The lead wire will be inserted through the introducer into the blood vessel. The doctor will advance the lead wire through the blood vessel into the heart.
4. Once the lead wire is inside the heart, it will be tested to verify proper location and that it works. There may be 1, 2, or 3 lead wires inserted, depending on the type of device your doctor has chosen for your condition. Fluoroscopy, (a special type of X-ray that will be displayed on a TV monitor), will be used to position the lead.
5. The ICD generator will be slipped under the skin through the incision (just below the collarbone) after the lead wire is attached to the generator. Generally, if you are right-handed, the device will be placed in your upper left chest. If you are left-handed, the device will be placed in your upper right chest.
6. The ECG will be observed to monitor ICD function. Certain tests may then be done to assess the device function.
7. The skin incision will be closed with sutures, adhesive strips, or special glue.
8. A sterile bandage or dressing will be applied. (hopkinsmedicine.org)
Risks of using an ICD is:
Implantable cardioverter defibrillators (ICDs) can sometimes give electrical pulses or shocks that aren't needed.
A damaged wire or a very fast heart rate due to extreme physical activity may trigger unnecessary pulses.
Swelling, bruising, or infection at the area where the ICD was placed
Bleeding from the site where the ICD was placed
Blood vessel, heart, or nerve damage
A collapsed lung
A bad reaction to the medicine used to make you relax or sleep during the surgery
Benefits of having an ICD is that It continuously monitors your heart and restores your heart to its normal heart rate. It’s like having an emergency response team with you 24 hours a day, 7 days a week. This will last for 7 years as it has a long-life time then you will be assessed to see if another ICD is needed.
Having an ICD implanted is an effective method because it doesn’t require a lot of medical attention after the procedure is complete. But risks that can happen in the future are unnecessary pulses which can be very strenuous on the chest area.
Reliability and Validity of sources
The sources I have used in this research task can be deemed reliable and valid. They are valid because they all have something to do with the topic being researched. They are reliable because all of the information used from the websites and textbook come from medical practices and most of them are organisation or government approved websites.