Cardiovascular Diseases: Types, Prevention and Treatment
Introduction
Cardiovascular diseases are the leading cause of mortality in the world. The diseases associated with the cardiovascular system, also known as the circulatory system, usually end with heart attacks and strokes due to blood clotting and blockage of the coronary arteries. This coronary artery disease essay examines coronary artery disease, focusing on how electrocardiographs and angiograms are used to diagnose the disease, and how stents are used to alleviate the narrowing of the blood vessels and reduce the patient’s blood pressure. Before investigating the biomedical devices aforementioned, an analysis of the anatomy and physiology of the cardiovascular system will be conducted.
Scope of the report
The report herein spotlights the cardiovascular system with a focus on the effects of coronary artery disease. The research focal point is on two specific biomedical devices that diagnose cardiovascular diseases, and one specific drug associated with alleviating the symptoms related to the disease. There are several ways of analyzing and treating coronary artery disease, but, we as researchers, have focused on these three techniques.
Physiology and structure of the cardiovascular system
As we all know, the cardiovascular system is made up of more than just the heart. It encompasses the blood vessels, making up a grid to transfer blood and fluid throughout the body with the heart works as the central, or key, organ of the system. An adult heart pumps around 7200 liters of blood every day. A system that is closely associated with the respiratory system, the lungs, also plays an important part in the cardiovascular system. Pulmonary circulation, or circulation relating to the lungs, is the process of transporting deoxygenated blood from the right ventricle of the heart to the lungs, and back to the left ventricle of the heart. The heart has a series of arteries that supply it with the sustenance of blood to survive. These arteries are called the coronary arteries. The coronary arteries branch off the aorta, and again into smaller arteries, sustaining the heart itself with oxygenated blood and maintaining the rhythmic contraction of the body's most important muscle.
The coronary arteries, and the crucial part they play in nourishing our heart, can be obstructed with the introduction of plaque, or cholesterol-containing deposits, also known as arteriosclerosis, causing the arteries to narrow, decreasing, or eliminating blood flow. This eventually will result in a heart attack and death. This build up is called arteriosclerosis. It leads to coronary heart disease. It can develop throughout a person’s life. According to the National Heart, Lung, and Blood Institute, “you can control some risk factors, such as lack of physical activity, smoking, and an unhealthy diet. Others you can't control, such as age and a family history of heart disease”. Symptoms of arteriosclerosis includes chest pain, or angina, shortness of breath. The most severe symptom is a heart attack. The diagnosis of coronary artery disease can be reached through medical and family history, physical examination, and test results. Dealing with the illness, a physician may advise lifestyle changes, medication and surgery.
Electrocardiography
Electrocardiography is a biomedical instrument which takes electrical impulse produced by the heart muscles during contraction and relaxation. ECG electrodes are connected to the patient and electrode catches potential difference and take to the lead selector. Lead selector selects leads accordingly to the program and the signal is given to pre amplifier and it is connected to power amplifier. In power amplifier a feedback network is connected and pen motor is connected to power amplifier. According to the power amplified signal pen motor print electrocardiogram. Along with that chart transport motor also have a standard speed of 25mm/s. Because variation in the speed of chart transport would affect ECG waveform.
Using electrocardiograph stress could be measured by treadmill test. In treadmill test patient need to walk and gradually run in the treadmill. While doing exercise heart rate and blood pressure got increases and ECG could measure it which is helpful for identifying health condition and can treat accordingly.
Procedure of ECG
In the resting position Electrocardiogram, patient should be in lied position and electrode are placed over the arms, legs and chest accordingly to the type of leads used in the ECG machine The electrode picks the current and transmitted to the electrocardiograph and the result could be printed by in build printer in the ECG machine or transferred to the computer using USB cable. Patient should not have any electronic items while taking electrocardiograph because electronic signal interferes ECG machine. A normal ECG machine is recognized by particular waves. It includes P wave, QRS complex, T wave, P-R interval, S-T segments and QT interval.
Heart Problems Diagnosed by ECG
- congenital heart defects involving the conducting (electrical) system
- abnormal rhythm (arrhythmia) – rapid, slow or irregular heart beats
- damage to the heart such as when one of the heart’s arteries is blocked (coronary occlusion)
- poor blood supply to the heart
- abnormal position of the heart
- heart inflammation – pericarditis or myocarditis
- cardiac arrest during emergency room or intensive care monitoring
- disturbances of the heart’s conducting system
- imbalances in the blood chemicals (electrolytes) that control heart activity
- previous heart attacks.
Pathophysiology
A person is considered to have coronary artery disease when the arteries that supply blood become hardened or narrowed down. According to the class textbook, Anatomy & physiology: an integrative approach, this disease occurs when a person has too much cholesterol and it builds up in the person’s vessels. Healthy amounts of cholesterol play key functions in maintaining a healthy body, such as forming cell membranes, synthesis of hormones, etc.. However, if a person has an imbalance of it, their body can be at risk of coronary artery disease. The body produces two different cholesterol carriers which carry cholesterol through the bloodstream, these are the low density(LDL) lipoproteins and high density lipoproteins(HDL). Low density lipoproteins are responsible for delivering cholesterol throughout the body to cells wherever it is needed. The normal level of LDL for a healthy person should be under 100 mg/dL, and if the person has risks of cardiovascular diseases, the levels of cholesterol should be under 70 mg/dL. The higher a person’s cholesterol levels are, the more at risk he or she is of a heart disease. This is because the LDL accumulates in the person’s blood vessels, where it can cause blockages leading to heart diseases like coronary artery disease. High density lipoprotein, on the other hand, is typically considered the “healthy” cholesterol. It absorbs cholesterol and carries it back to the liver, where it can get flushed out from the body if it is not needed. The levels of HDL in a healthy person is typically between 40 mg/dL to 60 mg/dL. Higher levels of HDL are considered healthier while lower levels are worrisome. Due to its functions of getting rid of excess cholesterol from the body, it does the opposite of LDL and prevents accumulation of cholesterol in the body. Thus, lowering risks of plaque, blood clots, and other diseases, therefore, higher levels of HDL are considered very good.
If a person does get coronary artery disease, it is because cholesterol and other minerals build up within the vessels. According to “Pathophysiology of Coronary Artery Disease” Coronary artery disease is the hardening and narrowing of the arteries. This is because of a buildup of cholesterol and other materials, also called plaque on the inner walls. This buildup is called atherosclerosis and the built up area is called a lesion. This is why people who are obese or have diabetes are more likely to have coronary artery disease because the obesity means the person have high triglycerides, which means he or she has high LDL cholesterol and low HGL cholesterol. Which means that person very susceptible to coronary artery disease since this setting is ideal for plaque to form. With diabetes, the blood vessels are damaged and weakened over time, which can typically lead to coronary artery disease. Next, there are actually two types of lesions that can form that are called stenotic and non-stenotic. A stenotic lesion has a thick cap surrounding the plaque with smaller lipid cores, and more fibrosis and calcification. They typically produce ischemia which can be managed by combined medical therapy and revascularization for symptom relief. Meanwhile, a non-stenotic lesion is more lipid rich and has a thin, fibrous cap around the plaque, which makes it possible for the lesion to rupture inside the vessel, leading to a lot of damage to a person’s body. These tend to undergo substantial enlargement when disrupted. Management of non-stenotic lesions include lifestyle changes and drugs for high-risk individuals. Monitoring these two types of lesions are essential to prevent patients from having heart attacks induced from their coronary artery disease.
Diagnosis
According to “Chronic Coronary Artery Disease: Diagnosis and Management”, Coronary artery disease is the most common cause of death in the developed world, responsible for about 1 death in every 5. Therefore, being able to diagnose it and help the patients is a very important priority to prevent more deaths from this disease. Chronic stable angina is the initial symptom that about 50% of all coronary artery disease patients have. Angina is due to an imbalance between myocardial oxygen supply and demand, resulting from myocardial ischemia. The angina pectoris is characterized by substernal discomfort, heaving, or pressure-like feeling, which can radiate to the jaw, shoulder, back or arm for several minutes. Coronary artery disease may also be asymptomatic and lead to sudden death. Physical examination is often unrevealing in patients with stable angina. However, the examination can check for hypertension, tobacco stains, chronic lung disease, xanthelasma, and evidence of noncoronary atheroscletic disease, which are all essential findings because it is important in determining the risks and benefits of certain treatment strategies and the need for additional investigations. An electrocardiogram can be conducted to identify possible irregularities in the person’s heart rhythms, which is another symptom of coronary artery disease. Imaging tests may also be used such as magnetic resonance imaging or adenosine nuclear perfusion tests can also be used to diagnose patients.
Risk factors
There are many factors that patients have that can increase their risk of getting coronary artery disease. According to “Chronic Coronary Artery Disease: Diagnosis and Management”, lifestyle choices like smoking can greatly increase the patient’s risk of getting the disease. This is because smoking increases the formation of plaque in the blood vessels. Smoking makes the human take in chemicals that cause the blood to thicken and form clots in veins and arteries, which only help to induce coronary artery disease or make it worse. Being physically inactive can also induce coronary artery disease due to it being associated with strokes, cancers, osteoporosis, obesity, type 2 diabetes, and hypertension. All of which is also associated with coronary artery disease. Another reason why people should exercise and try to eat healthier is because high blood pressure also induces people to have coronary artery disease over time as well. Patients that aren’t active or have blood pressure increasing illnesses like diabetes are much more likely to get cardiovascular diseases like coronary artery disease due to it putting so much more pressure on the heart to either pump more than it is used to or pump blood through high pressure bloodstream as compared to a normal active person. Lastly, the patient’s genetics or family history of coronary artery disease is an important risk factor that doctors should always keep in mind as well. If a patient has a family history of heart attacks before the age of 60, the patient is significantly more likely to develop cardiovascular diseases like coronary artery disease as compared to a patient who doesn’t have such a background.
Methods of Treatment
The typical way to treat coronary artery disease is to first start with a few lifestyle changes. According to “Prevention and Treatment of Coronary Heart Disease” changes like making the patients quit smoking, control their weight, having them eat a diet low in saturated fat and high in fruits and vegetables, and making sure they exercise a certain amount can prevent this disease entirely, stop it from getting worse, or lower the probability of a cardiovascular event occurring due to this disease. The doctor can also prescribe statins. Statins are drugs that work by reducing the low density lipoproteins in the body, leading to less cholesterol in the bloodstream which in turn lessens the effects of coronary artery disease. Statin treatment is very helpful and can be expected to prevent a great number of acute coronary events that occur in patients. According to “Pathophysiology of Coronary Artery Disease”, If the coronary artery disease is more serious, the doctor can do a percutaneous coronary intervention, otherwise known as a stent. This is a netlike support with a balloon catheter that is pumped inside the affected area of the vessel and creates an opening for blood flow to continue without the blockage of plaque. Another option is for the doctor to do a coronary artery bypass graft. This is when the blocked or affected coronary artery is grafted to a working vessel in the body to continue blood flow in the body, thus making the blocked vessel of the heart obsolete. The survival rates are essentially the same for both procedures, however, patients who go for percutaneous coronary intervention procedures are more likely to be revascularized.
Prognosis
Usually, a patient starts off with high cholesterol before coronary artery disease starts developing. According to “Chronic Coronary Artery Disease: Diagnosis and Management”, there are a lot of ways the disease can progress depending on each patient. Usually, about half of the patients will have angina, which is caused by myocardial ischemia, which is typically a result of coronary artery disease. The patient will usually be tested and treated for myocardial ischemia. If it is left undiagnosed and untreated, this patient can suffer from a heart attack. Depending on the severity, treatment can include statin drugs, using a stent or bypass surgery to treat myocardial ischemia. Usually, the patient will need to make heart-healthy lifestyle choices to treat it and prevent more myocardial ischemia. Sometimes there are asymptomatic patients that doctors have to test to make sure their disease isn’t severe. Asymptomatic patients typically don’t need a lot of treatment other than just getting prescribed statin drugs and getting requested to change their habits to be more heart healthy. However, if the doctor does a physical examination and there are signs to worry about for the patient, the doctor more tests or imaging to ensure that the patient is safe. The treatment will typically be the same as symptomatic patients if the asymptomatic patient is diagnosed as being more ill than he or she feels. Typically after treatment, patients will not be able to be as active as they once were when they were healthy but as long as they commit to living a healthier lifestyle and taking their medication, they can still enjoy their everyday life like a normal person.
Conclusion
Overall, there was a lot I learned through this research paper. I learned the specifics of how important the proper function of blood is to the human body and how the heart functions to ensure that humans stay functional and healthy. Next, I found how coronary artery disease impacts the human body and how harmful it can be if left untreated. Then I learned how to diagnose coronary artery disease through different methods depending on the patient’s symptoms and situation. In addition, I found how coronary artery disease can be treated. It is good to know the different types of treatments that produce similar results so that we know which should be applied depending on what the patient prefers or depending on the situation the patient is in. Lastly, I learned the typical courses of how coronary artery disease can impact the patient. All of this was very educational and I feel it’s important to know diseases in detail if I plan to become a nurse in the future, therefore by doing this paper I feel like I get a dip of the knowledge a nurse must have to take care of patients.
