Heart disease is prevalent, especially in western cultures and affects both men and women, often proving fatal. In the UK alone it is the single largest cause of death with coronary heart disease being the biggest cause of death in the under 65s (www.bnf.org.uk). With our increased awareness of healthy foods, how much exercise we need and how bad vices such as smoking and alcohol consumption really are, perhaps this should be having an impact on the numbers of people suffering with the illness. The advancement of diagnostic tests has even allowed the public to go to their local pharmacy and have their cholesterol level monitored, promoting the need for change in peoples lifestyles and access to the information to do so. Although is this change alone enough to reduce the risk?
There are many types of heart disease with varying grades of severity and these are summarised in Table One, although congenital abnormalities are not considered here.
Table One - Types of Heart Disease and their Causes (information from Waugh and Grant 2002)
Disease Sub group Effect Triggers
Cardiac Failure Acute Sudden decrease in blood output Muscle damage, hypertension, valve rupture, cardiac arrhythmia, acute toxic myocarditis, pulmonary embolism.
Chronic Gradual decline in efficiency as heart fails to be able to compensate Hypertension, myocardial fibrosis, valvular disease, lungs disease, anaemia, acute cardiac failure, old age.
Congestive (Right sided) Right ventricle can’t create pressure needed to push the blood Increased vascular resistance in the lungs (caused by lung diseases), myocardium weakness, incompetence of valves.
Ventricular (Left sided) Left ventricle can’t create pressure higher than aorta to push out all blood received. High systemic (aortic) blood pressure, aortic/ mitral valve incompetnce, arotic valve stenosis, myocardial weakness.
Valve disorders Stenosis Narrowing of valve opening. Inflammation, encrustations, rheumatic fever, fibrosis after inflammation and congenital incompetence.
Incompetence Failure of valve to close properly Functional defect, result of stenosis.
Ischaemic Heart Disease Angina pectoris Narrowing of a coronary artery. Increased demand on heart, can occur during excerise, cold weather or with strong emotions, hypertension.
Myocardial Infarction Area of tissue dies due to occlusion of a coronary artery. From plaques and thrombosis.
Rheumatic Heart Disease Rheumatic Fever Inflammation of endocardium causes fibrosis and eventual stenosis of valves, Aschoffs bodies (pale areas) form on myocardium, inflammation of pericardium affects expansion of heart. Follows throat infection by Streptococcus pyogenes as antibodies to the infection damage heart.
Subclinical Rheumatic fever Repeated subclinical attacks. Original disease remains active.
Infective Endocarditis Bacteraemia Microbes adhering to platelets and settling in damaged endocardium. Cause by wide range o f microbes with various pathogeneicity.
Depressed Immune Response Microbes can establish infection with little interference. Cytotoxic drugs, ionising radiation, anti-inflammatory druga, malignant and auto immune diseases.
Acute Settled microbes destroy tissue, cause pus formation. Highly virulent microbes (Staphylococcus aureus).
Subacute Microbes don’t form pus, healing via fibrosis increases stenosis. Low virulent microbes.
Cardiac Arrhythmias Sinus bradycardia Disorder of heart rhythm from abnormal generation/conduction of impulses. <60 beats/ min. Can follow myocardial infarction or raised intracranial pressure.
Sinus tachycardia Disorder of heart rhythm from abnormal generation/conduction of impulses. >100 beats/ min Fever, hyperthyroidism, cardiac conditions, exercise or anxiety.
Asystole No cardiac output as no electrical activity between ventricles.
Ventricular/ artial Fibrillation Contractions are disordered. Ischaemic or rheumatic heart disease, thyrotoxicosis, old age.
Heart Block Impulse formation is impaired or there is no conduction of impulse. Acute ischaemic heart disease, myocardial fibrosis, drugs for heart disease.
Hypertension Benign and Malignant Heart has to work harder for same output, when no more compensation can occur blood collects in lungs and leads to ventricular failure. Renal disease leading to cardiac failure, inherited, obesity, alchol intake, smoking, lack of exercise.
Pulmonary Raised pressure in pulmonary circulation. Blood vessel changes, respiratory diseases, heart diseases, disease to other organs that increase pressure in heart (e.g. liver)
The many different types of heart disease have more than one trigger and many of these causes also overlap. It can clearly been seen from Table One that many of the predisposing factors can be reduced by following a healthy lifestyle as the four main lifestyle related risks factors for coronary heart disease are smoking, lack of physical activity, high blood pressure and high blood cholesterol (www.bnf.org.uk). However not everyone understands the need or the importance of this lifestyle and aspects of it are often over looked in favour of activities such as fast food or watching TV after a days work, which also may not have involved much physical activity.
According to the British Heart Foundation (www.bnf.org.uk) there are five things that both people suffering from heart disease, and those just trying to prevent the onset of the disease, can do to reduce their risk and improve the health of their heart. These are:
Reducing the amount of saturated fat in the diet would help to prevent the clogging of the arteries and thus reduce the strain on the heart so it could function at a normal and not over compensatory level. Some foods containing these so-called ‘bad’ fats are red meat, cakes, biscuits, pastries, chips and dairy products. Another fat related risk factor is cholesterol, a fatty substance made in the body as opposed to consumed in the diet (it is only found in eggs, liver and kidneys), and used as a component in cell membranes and other essential molecules. Too much cholesterol carried in the blood can increase the risk of heart disease. This is because the blood lipids (including Low Density Lipoproteins (LDL) - proteins carrying cholesterol from the liver to the cells, High Density Lipoproteins (HDL) - proteins returning unnecessary cholesterol to the liver and Triglycerides) composition affects the risk of heart disease e.g. high LDL but low HDL or high levels of triglycerides increases the risk (HIS02). Changes in diets to include more good fats, such as provided in fish and olive oil, as well as including more fresh fruit and vegetables and cutting down on the salt and processed food intake are all beneficial changes to reduce cholesterol and reduce the chance of heart disease, however other implications such as cost of the new lifestyle and time implement this need to be addressed.
All that the BNF suggest is half an hour a day of an exercise that increases your heart rate. Not every one has the budget to join a gym but anything from walking the last two bus stops home could help. It is recommended that people exercise at a level that they can cope with to avoid unnecessary strain on the heart.
Smoking causes damage to the coronary arteries and deposits fat in them (atherosclerosis), which again will increase the work the heart has to do to maintain the same blood supply. Stopping smoking at any point, even after diagnosis with heart disease, will help to reduce the risk and after one year of not smoking the risk of heart disease is halved. The carbon monoxide from the cigarettes displaces the oxygen in the red blood cells and thus reduces the amount of oxygen that the heart and other organs are getting, thus the heart must work harder to get the same amount of oxygen to the tissues. Nicotine also stimulates the body to produce adrenaline which increases the heart rate and blood pressure, again causing unnecessary strain. There are many items on the market to help people stop smoking but the latest advance is an American drug, Bupropian tablets (Zyban), used initially to treat depression that also helped to stop people smoking by reducing the nicotine craving (HIS02), although the will power to stop and the influence of the company you keep can also affect this.
Binge drinking increases the risk of heart attacks by increasing blood pressure. For every unit over the recommended daily amount the systolic blood pressure could rise by 1mmHg (HIS02). Normal blood pressures are 140/90 mmHg for 20 year olds, 160/95 mmHg for 50 year olds and 170/105 mmHg for 75 year olds (Waugh and Grant 2002). Moderate drinking is between 1 and 2 units of alcohol a day (one unit is half a pint of beer, pub measure of spirit or a small glass of wine). This amount can even be beneficial to the heart by having a protective effect against these diseases in men over 40 and post menopausal women (HIS02). Although this is probably the hardest to adhere to as statistics show the UK having the highest incidence of binge drinking sessions (more than half governments recommended alcohol allowance for a week in on session) with report of 40 sessions per year for men and 22 sessions per year for women (IAS 2004).
Increased levels of fat mean the body has extra weight to carry and therefore the heart has to work harder to supply blood around the body. Obesity also increases the amount of fats in the blood which can also begin to deposit in the arteries. Other reasons for obesity, such as the type of job the person does or the social and leisure activities they engage in, which can be affected by social class, are also factors that may can influencing their risk group.
Changes to healthier lifestyles are very advantageous to reducing the risk of heart disease but sometimes it can be hard to stick to them or even just to begin to change even small aspects as these changes have repercussions on other aspects of their lifestyle. In the cases where a dramatic changes need to be made there are other treatments available, such as surgery or more commonly, drugs. There are many different types of drugs used to treat different forms of heart disease and its complications (angina, heart attack, heart failure, high blood pressure/ cholesterol, valvular heart disease, arrhythmias) usually by modifying the way the heart works, although some can be taken as a preventative medication others need diagnosed symptoms before use (HIS17). Table Two shows the drugs that can be used, though, as with any drug there are associated side effects and risks by taking them.
Table Two: Type of Drugs for the Treatment of Heart Disease (information from HIS17)
Drug Examples Used for Problems
ACE (Angiotensisn Converting Enzyme) inhibitors and Angiotensin II Antagonists Ramipril, lisinopril, perindopril Heart failure, to lower blood pressure by relaxing arteries Can effect kidneys and liver
Anti-arrhythmic drugs Amiodarone, flecainide, propafenone, digoxin Control heart rhythm Loss of appetite, nausea
Anticoagulants Heparin, warfarin. Prevent clotting (fibrin formation) Can make bleeding problematic
Anti-platelet drugs Asprin, clopidogrel, abciximab, tirofiban Reduces platelet stickiness Indigestion, nausea, asthma
Beta-blockers Carvedilol, metoprolol, bisoprolol Prevent heart beating too quickly by blocking adrenaline, lower blood pressure Can narrow air passages, tiredness, sickness, rashes, impotence
Calcium channel blockers Nifedipine, amlodipine, lacidipine, diltiazem, verapamil Increase blood supply to heart, reduce heart work rate Headache, fainting, indigestion, swollen ankles
Cholesterol lowering drugs Simvastatin, pravastatin, atorvastatin Lower blood cholesterol Nausea, vomiting, headache, muscle inflammation
Diuretics Thiazide diuretics, loop diurectics and potassium sparing diruretics Increase salt and water loss, lower blood pressure. Worsen gout, tests for blood salt levels are needed
Nitrates Glyceryl trinitrate, isosorbide mono/di nitrate Relax artery walls Headaches, dizziness, fainting
Potassium channel activators Nicorandil Relax coronary arteries Headache, indigestion,
Thrombolytic drugs Steptokinase, alteplase, tenecteplase Quickly dissolve clots Cause serious bleeding
Most of these, and other drugs not mentioned above, would be prescribed by a doctor, and therefore certain symptoms would need to be recognised for treatment, something which is affect by the level of education of the individual. However, it is common for people to use preventative general sale medication, such as aspirin, to reduce their risk of heart disease. Not all of the drugs taken for heart disease directly affect the heart; cholesterol reduction drugs affect the blood cholesterol level but also need to be used in conjunction with a change in diet. Hypertensive drugs would work to lower blood pressure, which as a beneficial secondary effect, would reduce the strain on the heart.
British Heart Foundation - www.bnf.org.uk
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