Cardiovascular disease
Transient ischaemic attack (TIA)
A transient ischaemic attack, usually shortened to TIA, happens when the blood supply to part of the brain is interrupted for a short time. The name explains it, since transient means temporary and ischaemic means a restricted blood supply. The effects pass, but the cause of them does not, which is why a TIA is investigated with the same seriousness as a stroke.
What a transient ischaemic attack is
A transient ischaemic attack happens when the blood supply reaching part of the brain is briefly cut off and then restored.
The brain requires oxygenated blood to function properly. Any restriction or blockage to the supply of blood to the brain stops brain cells working, which leads to the loss of brain function. In a stroke that interruption continues, brain cells die, and the damage can be lasting. In a transient ischaemic attack the flow returns, so the effects settle.
Because the underlying problem is the same one, a TIA is taken every bit as seriously as a stroke. The clot, the narrowed artery or the irregular heart rhythm behind it is still present afterwards, and the purpose of the assessment that follows is to find it and treat it.
Why the blood supply is interrupted
Most interruptions to the blood supply of the brain are caused by a blood clot. Blockages of this kind account for around 85% of strokes in the UK, and the clots involved are formed through the process of atherosclerosis.
Atherosclerosis is the build-up of fatty deposits inside the artery wall. As it progresses it damages the vessel wall, or the wall ruptures, and that may lead to a blood clot forming. A clot of this kind is known as a thrombus.
A thrombus might also break off from the original vessel and move in the blood, which is known as an embolus. An embolus that travels to the brain blocks the flow of blood there. Clots can also form inside the heart itself and then travel, which is why heart rhythm problems matter a great deal in this context.
A TIA is an ischaemic event, meaning it is caused by a restriction in blood flow rather than by bleeding. The other main type of stroke is haemorrhagic, which occurs when blood vessels supplying blood to the brain become weakened and burst or rupture, and this accounts for around 15% of all strokes.
Conditions that raise your risk
Certain conditions increase the risks of a stroke occurring, and the same conditions raise the risk of a transient ischaemic attack.
Some influences sit outside your control. Blood pressure usually rises with age due to the stiffening of the arteries. Studies have proven links between low socioeconomic status as well as BAME (Black, Asian, or Minority Ethnicity) backgrounds with higher blood pressure levels.
Someone who has already had a stroke is at higher risk of having another one without any changes to their diet, alcohol intake, and exercise capability. The same reasoning applies after a transient ischaemic attack, and it is the reason the assessment afterwards looks at every risk factor rather than only at the event itself.
- High blood pressure. This impacts the walls of the blood vessels and weakens them, adding increased strain, which can lead to a rupture. Blood pressure of 140/90mmHg or higher when checked by a healthcare professional is classed as hypertensive.
- High cholesterol. This increases the fatty deposits inside the arteries, leading to atherosclerosis and plaque build-up which aids in forming a clot.
- Atrial fibrillation. AF means that blood is not pumped properly and so can stagnate in the heart, causing clots to form which can travel to the brain and other organs.
- Diabetes. This increases the risk of blood vessels becoming brittle and weak, making them stiffer over time, which can cause damage and can also burst or cause a rupture.
How a transient ischaemic attack is investigated
Stroke prevention is one of the fields Dr Jogiya lists among his specialist areas. The cardiology part of the assessment is concerned with where a clot could have come from and which risk factors are driving the problem, and it usually begins by recording the electrical activity of the heart.
A 12 lead ECG measures the heart's electrical signals and shows whether the rhythm is irregular. It is the most common test used to confirm atrial fibrillation. If an irregular rhythm only occurs occasionally, longer monitoring may be recommended, using a portable ECG monitor worn for 24 hours or longer so that an episode can be captured while it is happening.
An echocardiogram examines the structure and function of the heart. It shows how well the chambers are pumping, which matters here because blood that is not pumped effectively can pool inside the heart and allow clots to form.
Blood pressure is measured on more than one occasion, because a single elevated reading does not always confirm hypertension. Dr Jogiya might ask for an ambulatory blood pressure monitor to record measurements throughout the day and calculate an average blood pressure reading. Blood tests form part of the same workup and are the route to a cholesterol check.
Treatment and lowering the risk of a stroke
Treatment after a transient ischaemic attack is aimed at the cause rather than at the episode, which has already passed. Medication is used to reduce the risk of a further event, and the combination depends on what the investigations find.
Blood thinners, cholesterol medication and blood pressure medicines are all used to reduce the risk of recurrence. Patients diagnosed with atrial fibrillation may often also be commenced on blood thinning medication to prevent the risks of stroke or other blood clot formations in the heart. Controlling cholesterol levels usually requires medication alongside a controlled diet.
Treatment for high blood pressure starts with lifestyle changes in diet and exercise. If lifestyle changes do not make a difference, then medication can be given to help control blood pressure levels. Different medicines work for different people, and sometimes the first medicine might not always be the most suitable. Medicines will depend on age, ethnicity, and average overall blood pressure levels.
Lifestyle choices can always help. Increasing exercise, losing weight, reducing stress, and avoiding coffee or alcohol can all help to reduce and manage your blood pressure. A balanced diet, cutting down on alcohol, quitting smoking, losing weight and regular exercise all improve cardiac health more broadly.
Where a stroke has already occurred and was caused by a blood clot, a procedure known as a thrombolysis is performed to break the clot, and sometimes a clot needs to be surgically removed. That is emergency hospital treatment rather than something arranged in a clinic, which is one of the reasons sudden symptoms need an ambulance and not an appointment.
When to call 999
A stroke is a serious, life-threatening condition that requires immediate and urgent treatment to minimise the damage to the brain and allow for a better prognosis. If it is not treated immediately, a stroke can lead to brain damage, severe disability, and even death.
The signs come on suddenly, and the way to recognise them is the word FAST, which is what NHS advice uses.
If you or someone with you develops a sudden change in the way the brain is working, call 999 straight away. Do this even if it lasts only a few minutes and then passes completely. There is no way to tell at the time whether what is happening is a transient ischaemic attack or a stroke, and the treatment that limits damage to the brain works best when it is given quickly.
If symptoms have already settled, that is a reason to be assessed rather than a reason to wait. You can contact the practice to arrange a consultation with Dr Jogiya, who will look for the cause and put treatment in place to lower the risk of a stroke. Anything sudden or ongoing remains a 999 call.
- Face. One side of the face may droop, and it might be hard to smile.
- Arms. They may not be able to lift both arms and keep them there, because of weakness or numbness in one arm.
- Speech. They may slur their words or sound confused, or be unable to speak at all.
- Time. If you see any single one of these signs, it is time to call 999. Do not wait for the others, and do not wait to see whether it passes.
Where the figures on this page come from
Every figure above is quoted from one of these. This page is general information, not individual medical advice.
More in cardiovascular disease
Related conditions he treats.
- AnginaAngina is a chest pain that comes on when the flow of blood to your heart muscle is reduced, usually because the arteries supplying it have been narrowed by fatty substances. It is a symptom rather than a disease in its own right, and it tends to appear when your heart is asked to work harder, then settle again after a few minutes of rest. Angina is not usually life threatening on its own, but it is a signal worth taking seriously, because it can warn that you are at higher risk of a heart attack or a stroke, and chest pain that is new or has changed its pattern always needs prompt medical assessment.
- Coronary artery diseaseCoronary artery disease, often shortened to CAD, affects the coronary arteries, the blood vessels that supply the heart with oxygenated blood so the muscle can keep pumping. When those arteries become narrowed or blocked, the heart muscle can be left short of the blood it needs. Over time this can lead to worsening symptoms and can cause angina, heart attacks and other serious events.
- Heart attackA heart attack is what happens when a portion of the heart muscle is deprived of blood flow, which is why doctors usually call it a myocardial infarction, or MI. Without fresh blood that area of muscle receives no oxygen and begins to die, so it stops moving and stops pumping efficiently. Heart attacks can be treated if they are detected early, so the symptoms below are worth knowing, and any suspected heart attack is a 999 call rather than something to wait out.
- High blood pressureHigh blood pressure, also known as hypertension, means the force of blood pushing against the walls of your arteries stays consistently too high. Readings of 140/90mmHg or higher when checked by a healthcare professional are classed as hypertensive, against a normal range of 90/60mmHg to 130/85mmHg. It often develops quietly over time without causing any obvious symptoms, which is why regular measurement matters so much.
- Low blood pressure (hypotension)Low blood pressure, also known as hypotension, means the pressure inside your blood vessels is lower than it needs to be. Blood pressure below 90/60mmHg is classed as hypotension, and they can cause symptoms such as dizziness and fatigue. When blood is not being pumped with enough pressure to meet the body's needs, it can lead to fainting or blackouts, otherwise known as syncope.
- StrokeA stroke is a serious, life-threatening condition that occurs when the blood supply to a part of the brain is cut off. The brain needs oxygenated blood to function properly, so any restriction or blockage causes brain cells to die and brain function to be lost. A stroke requires immediate and urgent treatment, so if you think you or someone with you may be having one, call 999 straight away.