Atrial fibrillation

Understanding atrial fibrillation

Atrial fibrillation, often shortened to AF, is the most common heart rhythm problem seen in adults. Instead of beating in an organised way, the heart's two upper chambers quiver rapidly and irregularly. Some people feel this clearly as palpitations; many others feel tired, breathless or notice nothing at all until it is found on a routine check. AF is rarely an immediate emergency, but it matters — mainly because of its link to stroke — which is why it should always be properly assessed and treated rather than ignored.

To understand AF, it helps to understand the normal heartbeat. The heart has four chambers: two upper chambers (the atria) that receive blood, and two lower chambers (the ventricles) that pump it onward to the lungs and body. Each normal beat begins as an electrical signal from the heart's natural pacemaker (the sinus node) in the right atrium, spreads across both atria in an organised wave, then passes through a relay point (the AV node) into the ventricles. This keeps the heartbeat regular and coordinated. In AF, instead of one organised wave, chaotic electrical activity sweeps across the atria at very high speed. The atria no longer contract properly — they quiver, or "fibrillate" — and only some of these chaotic signals get through the AV node to the ventricles, which is what makes the pulse feel irregular and often fast.

What atrial fibrillation feels like

AF affects people very differently. These are common descriptions patients use, offered to help you put your own experience into words for a clinician — not a checklist for diagnosing yourself.

• ●An irregular, fluttering or racing pulse
• ●Palpitations — an unpleasant awareness of the heartbeat
• ●Tiredness or reduced ability to exercise as usual
• ●Breathlessness, dizziness or mild chest discomfort
• ●No symptoms at all — AF is often found incidentally, on a routine pulse check, ECG or when investigating something else

AF can be occasional and self-settling, persistent and needing treatment to restore normal rhythm, or long-standing. The pattern matters for treatment, so noting how often episodes happen, how long they last and what you feel is useful information for your appointment.

What causes atrial fibrillation

AF can occur in an otherwise normal heart, but it is more often linked to another condition that has changed the structure or electrical behaviour of the atria.

Heart-related causes

High blood pressure is the most common contributor, because it gradually stretches and stiffens the atria over years. Other heart-related causes include valve disease, a previous heart attack, heart failure, and prior heart surgery.

Causes outside the heart

• ●An overactive thyroid gland speeds up the heart and can trigger or worsen AF
• ●Obstructive sleep apnoea, where breathing repeatedly pauses during sleep, strains the heart's rhythm
• ●Heavy or binge alcohol use, a well-recognised trigger
• ●Serious infection or illness elsewhere in the body, which can provoke a temporary episode
• ●Obesity, which increases strain on the atria over time

When no clear cause is found

In some people, particularly at older ages, AF develops from gradual age-related changes in the heart's electrical tissue without any single identifiable trigger.

Who is more likely to get atrial fibrillation

These factors make AF more likely, and are worth mentioning at your appointment:

• ●High blood pressure — very common in Nigeria and often undiagnosed, it is the single biggest driver of AF
• ●Increasing age
• ●Diabetes
• ●Existing heart disease, including valve disease and heart failure
• ●Thyroid disease
• ●Obesity
• ●A family history of atrial fibrillation
• ●Heavy alcohol use

Why atrial fibrillation matters: stroke and other risks

Most people with AF live full, active lives on the right treatment. The reason AF is taken seriously is its link to stroke, along with its effect on the heart's own pumping ability if left unaddressed.

Stroke — how it happens. In AF, the atria quiver instead of contracting properly, so blood does not move through them efficiently and can pool, particularly in a small pouch called the left atrial appendage. Pooled blood is more likely to clot. If a piece of that clot breaks free, it travels in the bloodstream and can lodge in an artery supplying the brain, blocking blood flow and causing a stroke. This is why AF-related stroke can happen without any warning symptoms from the heart itself — the danger is not the irregular heartbeat directly, but the clot it can quietly form.

Why anticoagulation matters. Anticoagulants ("blood thinners") act on the blood's clotting proteins to make clots less likely to form in the first place. For many people with AF, the stroke-prevention benefit of taking an anticoagulant consistently outweighs the bleeding risk it carries — but this balance is individual, which is why your clinician assesses your personal stroke risk and bleeding risk together, rather than treating all AF the same way.

Heart failure. A heart rhythm that stays abnormally fast for a prolonged period, if unrecognised, can gradually weaken the heart's pumping ability over time.

Fatigue and reduced quality of life. Ongoing symptoms or a heart rate that is not well controlled can limit daily activity and exercise tolerance.

How Cardiocare finds and assesses atrial fibrillation

The right pathway depends on your symptoms, examination and overall health. It typically draws on some or all of the following:

• 01
  History and examination. Checking your pulse for an irregular rhythm, and reviewing your symptoms and other conditions.
• 02
  12-lead ECG. A painless recording of the heart's electrical activity from pads on the chest and limbs, confirming AF while it is happening.
• 03
  Holter or event monitoring. A portable ECG recorder worn for a day or longer, useful when AF comes and goes and a standard ECG is normal in between.
• 04
  Echocardiogram. A painless ultrasound scan showing the heart's chamber size, valves and pumping function.
• 05
  Blood tests. Thyroid function, full blood count and kidney function, all of which affect both cause and treatment choice.
• 06
  Stroke-risk and bleeding-risk review. Your clinician weighs your personal factors — age, blood pressure, diabetes, prior stroke and others — to guide whether and how to anticoagulate.
• 07
  Sleep assessment. Where obstructive sleep apnoea is suspected as a contributing cause.

How atrial fibrillation is treated

Treatment usually addresses three things together: preventing stroke, controlling the heart rate or rhythm, and managing any underlying cause.

Stroke prevention

For most people with AF and one or more risk factors, an anticoagulant is the single most important treatment — it does not stop AF itself, but substantially lowers the chance of a stroke happening. Your clinician will explain your personal risk and the reasoning behind the recommendation.

Medicines, by class

Alongside anticoagulation, medicine choice depends on what it is meant to achieve:

• ●Anticoagulants (blood thinners) — reduce the risk of clot formation and stroke
• ●Rate-control medicines (such as beta blockers) — slow the heart rate to a comfortable, safe level even while AF continues
• ●Rhythm-control medicines — help restore and maintain a normal heart rhythm rather than simply controlling its rate

Procedures

Available through Cardiocare's on-site cardiac catheterisation laboratory:

• ●Cardioversion — a controlled electrical shock, under sedation, that resets the heart to a normal rhythm
• ●Catheter ablation — while sedated, thin catheters are guided through a vein, usually from the groin, to treat the tissue generating the abnormal signals, most often around the connections from the pulmonary veins into the left atrium
• ●Left atrial appendage closure — a device-based option considered for selected patients who cannot safely take long-term anticoagulation

Treating the underlying cause

Where AF is linked to another condition — blood pressure, thyroid disease, sleep apnoea or obesity — treating that condition is part of AF treatment, not a separate matter.

Living with atrial fibrillation: everyday self-care

• ✓Take your anticoagulant exactly as prescribed — missed doses reduce its stroke-prevention benefit
• ✓Never stop a blood thinner for another procedure, including dental work, without checking with your cardiology team first
• ✓Take rate- or rhythm-control medicines consistently, even when you feel well
• ✓Limit alcohol, and avoid binge drinking
• ✓Manage blood pressure, weight and, if relevant, sleep apnoea as part of ongoing AF care
• ✓Learn to check your own pulse for irregularity, and note when episodes happen
• ✓Attend planned follow-up, even between symptoms

Most people with well-managed AF continue normal work, family and social life, including most forms of exercise as advised by their clinician.

Preparing for your appointment

What to bring

• ✓A list of all medicines you take, including herbal and over-the-counter preparations
• ✓Any previous ECGs, blood test results or hospital letters
• ✓Your HMO card or payment details
• ✓A valid means of identification

What we will ask

When you first noticed symptoms, how long episodes last, how often they happen, and whether you have ever had a stroke, bleeding problem or thyroid issue.

Questions worth asking us

• ●What is my personal stroke risk, and do I need an anticoagulant?
• ●Should we aim to control my rate, or try to restore a normal rhythm?
• ●Is there an underlying cause we should treat?
• ●What should I do if I notice my pulse become irregular again?