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Tag: heart diseases

  • Heart Diseases XI-Heart attack

    A heart attack occurs when blood flow to part of the heart is blocked, often by a blood clot, causing damage to the affected muscle.
    This is usually caused by atherosclerosis – hardening of the artery walls. The clot, often caused by rupturing or tearing of plaque in an artery is sometimes called a coronary thrombosis or a coronary occlusion.
    If blood supply is cut off for a long time, muscle cells are irreversibly damaged and die, leading to disability or death depending on the extent of the damage to the muscle.
    A heart attack, also known as myocardial infarction, can also occur when a coronary artery temporarily contracts or goes into spasm, decreasing or cutting the flow of blood to the heart.
    An unexpected and abrupt heart attack occuring soon after the onset of symptoms can result in sudden death.
    It accounts for about half of all coronary heart disease deaths and can be caused by nearly all types of heart disease.
    Three main symptoms of a heart attack:
    1. Pressure or pain in the centre of the chest, lasting more than a few minutes or going away and coming back
    2. Pain spreading to the shoulders, neck or arms
    3. Chest discomfort combined with light-headedness, fainting, sweating, nausea or shortness of breath
    Other common warning signs of heart attack include unusual chest, stomach or abdominal pain, nausea or dizziness, shortness of breath or difficulty breathing, unexplained anxiety, weakness or fatigue, palpitations, cold sweat or paleness.

    What to do if someone has a heart attack
    Check the victim for a response
    If no response, ask someone to call for an ambulance. If you are on your own, do this yourself; you may need to leave the victim
    Check the victim is breathing normally
    If breathing is normal, place them in the recovery position and await help
    If not, open their airway using a head tilt and chin lift and begin 30 chest compressions
    Open the airway again and give two rescue breaths (mouth to mouth)
    Continue the chest compressions and rescue breaths in a ratio of 30:2
    For detailed instructions, visit the Resuscitation Council website.
    Anybody experiencing these symptoms should call an ambulance immediately, but should not try to drive themselves to hospital, as complications can begin to occur before they get there.
    Most people do have time to get to hospital and be treated before collapsing, but they do need to act quickly.
    Some people wait for hours or even days before seeking help – they are the ones that get into trouble.
    After a heart attack
    Diagnosis of a heart attack usually involves a clinical examination, an electrocardiogram, heart rhythm monitoring and blood tests.
    Echocardiograms or angiograms will detect the extent of damage to the heart.
    Immediately after a heart attack, clot-busting drugs will be used to restore blood flow. Aspirin, to aid blood flow, and beta-blockers, to ease the heart’s work rate, may also be used.
    In the days or weeks after a heart attack, surgery – either angioplasty or coronary artery bypass surgery – may be performed.
    http://news.bbc.co.uk/2/hi/health/medical_notes/g-i/764015.stm

  • Heart Disease VIII-Treatments – drugs-BBC.

    Medicines can control cardiovascular Medicines can control cardiovascular disease
    Drugs to treat heart conditions and stroke adjust the working of the heart or circulation of the blood.
    Most are taken orally as tablets or capsules to be swallowed, but they can come in the form of tablets held under the tongue, aerosols or patches.
    Drugs can also be administered directly into a vein or a muscle.
    ACE inhibitors
    ACE stands for angiotensin converting enzyme. Levels of angiotensin, a chemical which narrows blood vessels, are restricted by the drug, causing the arteries to dilate and leading to a fall in blood pressure.
    Types of ACE inhibitor include enalaparil, captopril and lisinopril.
    Side-effects include a fall in blood pressure, especially when combined with diuretics for the first time.
    Anti-arrhythmic drugs

    Anti-arrhythmic drugs act to control disturbances of the heart’s rhythm.
    Amiodarone is very effective but it has side effects, including headache, flushing, dizziness and stomach upsets.
    Flecainide is used for serious heart rhythm disturbances.
    Propafenone is used to treat intermittent or paroxysmal atrial fibrillation – where the heart beats fast and irregularly and may lead to heart failure. Its use is usually avoided in patients with asthma or chronic lung disease.
    Digoxin is used to treat atrial fibrillation. The drug slows the heart, relieving the symptoms of breathlessness and palpitation, but does not restore its regularity – additional treatment may be needed for this.
    Anticoagulants
    Clots consist of small blood cells clumped together – platelets – and a protein called fibrin.
    Anticoagulants prevent fibrin forming, but may cause or aggravate bleeding. Regular blood tests are necessary to ensure clotting is within safe levels.
    They are particularly useful for treating clots of the veins of the leg (deep vein thrombosis) and in preventing these clots travelling to the lung, causing pulmonary embolism. They do not dissolve existing blood clots.
    They are often prescribed to prevent repeat heart attacks or strokes.
    Heparin is usually given intravenously to urgently prevent further clotting.
    Warfarin and other oral anticoagulants are given to prevent clotting over a long period. It is usually used for patients with artificial heart valves or heart valve disease, but is also given to people with irregular heart rhythm.
    Aspirin (and other anti-platelet drugs)
    Traditionally used as a painkiller, aspirin is also effective in preventing clotting of the blood, by reducing the “stickiness” of the platelets.
    A smaller dose is needed than is required to relieve a headache.
    It reduces the risk of dying after a heart attack or suffering a further heart attack or stroke. It is also useful for patients with angina and to prevent blood clotting in the vein grafts used in coronary artery bypass surgery.
    But stroke patients should be aware that if their event was caused by a haemorrhage rather than a blood clot, aspirin could do more harm than good.
    Other anti-platelet drugs such as clopidogrel and ticlopidine have recently been developed, which can be used around the time of angioplasty to reduce the risk of blood clotting.
    Aspirin can cause indigestion, nausea, vomiting and constipation and so it is not recommended as a way of preventing heart attacks or strokes in healthy people.
    Beta-blockers
    Beta-blockers control the speed and force of heart beats by blocking the action of hormones such as adrenaline that make the heart beat faster and more vigorously.
    They are effective in preventing angina. They can also lower raised blood pressure, reduce the risk of further heart attacks and help control abnormal heart rhythms.
    Side-effects include constriction of the air passages and small blood vessels, leading to cold hands and feet. They can conceal low blood sugar levels in diabetics – “selective” beta-blockers are less likely to do this than other forms of the drug.
    Tiredness or fatigue may also be experienced.
    Calcium channel blockers (calcium antagonists)
    Calcium antagonists reduce the amount of calcium entering the muscle cells of the arteries, causing them to relax.
    This leads to the blood flow to the heart increasing and reducing the work the heart has to do to pump blood around the body.
    Types of the drug include nifedipine, diltiazem and verapamil.
    Side-effects include flushing, headache, dizziness, fainting, swelling of the ankles and stomach and gastro-intestinal problems.
    Cholesterol-lowering drugs (lipid-lowering drugs)
    Statins are the main type of drug used to reduce cholesterol levels. They can reduce levels of “bad” cholesterol – LDL (low-density lipoprotein) cholesterol – by more than 20%. They reduce the risk of dying of coronary heart disease by around 25%.
    Statins are not suitable for people who have liver disease or who are pregnant or breastfeeding.
    Two other forms of cholesterol-lowering drugs are available – fibrates and drugs which bind bile acids.
    Diuretics
    Diuretics, or “water tablets”, increase the output of water and salt in the urine.
    They are effective in treating heart failure, where there is an excess of water and salt in the body, and in lowering high blood pressure.
    They are often combined with digoxin and/or ACE inhibitors. To treat high blood pressure they are used alone or in combination with beta-blockers, calcium channel blockers, ACE inhibitors or other drugs.
    Diuretics can cause low potassium levels, and in diabetics, high blood sugar levels.
    Nitrates
    Nitrates relax the muscles in the walls of the veins and arteries and make them wider. They are useful for relieving angina pain and preventing predictable attacks.
    Glyceryl trinitrate tablets (also called GTN, trinitrate or nitroglycerin tablets) quickly relieve angina.
    A throbbing headache can result when GTN tablets are first taken, but symptoms tend to fade with time.
    Potassium channel activators
    Potassium channel activators, a new type of drug for angina, have a similar effect to nitrates as they relax the walls of the coronary arteries and therefore improve blood flow.
    “Clot-busters”- Thrombolytic drugs
    Used only when there is an urgent need to dissolve a clot, usually after a heart attack, the most common form of the drug is streptokinase, which is given directly into a vein.
    Repeat doses of some thrombolytic drugs, such as streptokinasae should not be given for several years.
    However, this is not the case for others, such as alteplase, reteplase and tenecteplase.
    http://news.bbc.co.uk/2/hi/health/medical_notes/g-i/764042.stm

  • Heart Diseases- IV-Stroke – ischaemic-BBC.

    Stroke caused by blood clots or other obstructions – ischaemic stroke – accounts for 80% of all cases.
    A blockage is called a cerebral thrombus or cerebral embolism and can be caused by atherosclerosis – hardening of the arteries.
    In both types of stroke – those caused by blood clots and those caused by burst blood vessels – blood supply to the brain is interrupted, depriving the cells of oxygen and other nutrients. The cells are then damaged or die.
    Mini-strokes, or transient ischaemic attacks (TIAs), may be a warning sign of an imminent full-blown stroke.
    Embolic
    In an embolic stroke, a blood clot – or embolus – forms somewhere in the body, usually the heart, and travels through the bloodstream to the brain.
    Once in the brain, the clot eventually travels to a blood vessel small enough to block its passage. The clot lodges there, blocking the blood vessel and causing a stroke.
    Thrombotic
    In the other form of blood-clot stroke, blood flow is impaired because of a blockage to one or more of the arteries supplying blood to the brain – a thrombus.
    The process leading to this blockage is known as thrombosis and strokes caused in this way are called thrombotic strokes.
    In atrial fibrillation, where the two upper chambers of the heart – the atria – quiver instead of beating properly, blood is not properly pumped out of the heart. As a result it may form clots and if the clot becomes lodged in an artery in the brain, a stroke may result.
    The American Heart Association says arond 15% of strokes are caused in this way.
    Blood clot strokes can also happen as the result of unhealthy blood vessels clogged with a build up of fatty deposits and cholesterol.
    The body regards these build ups as multiple, tiny and repeated injuries to the blood vessel wall and reacts as it would to bleeding from a wound, by forming clots.
    The symptoms of stroke:
    Sudden numbness or weakness of the face, arm or leg, particularly if it is on one side of the body
    Sudden confusion, trouble speaking or understanding. Sudden difficulty with walking, dizziness, loss of balance or co-ordination
    Sudden trouble seeing in one or both eyes
    Sudden severe headache with no known cause
    Anyone identifying themselves or friends or family as having a stroke should call emergency services, not a GP, as any delay reduces the chance of a full recovery.
    The speed of treatment after a stroke is extremely important as the longer the brain cells are deprived of oxygen, the more damage they will suffer.
    Treatment
    Clot-busting drugs can be used in the first minutes or hours – up to a maximum of three hours – after an ischaemic stroke to dissolve the clot.
    After this time aspirin, which is not as powerful, may be given.
    Survival rates are better for patients in specialist stroke units, because of the expert nature of staff and early use of rehabilitation, but such units are not always available.
    Rehabilitation programmes will be given to most stroke patients to help them recover lost mobility and speech.
    http://news.bbc.co.uk/2/hi/health/medical_notes/g-i/764070.stm

  • Heart Disease-2 -BBC

    Stroke details.
    HEART DISEASE
    The heart pumps blood around the body carrying oxygen and other nutrients to the areas that need it. When this process is interrupted, or does not work properly, serious illness and even death can result.
    The risk of heart disease is greater for people with poor diet, who smoke and do not exercise, and men are more likely to suffer from it than women.
    A range of tests and treatments, including drugs, heart bypass surgery and transplants, exist to alleviate symptoms or save the lives of sufferers.
    http://news.bbc.co.uk/hi/english/static/in_depth/health/2000/heart_disease/heart_disease.stm