Introduction 

Before exploring the symptoms of persistent atrial fibrillation (AF), it is important to understand some aspects of the heart and how it functions. 

The heart and sinus rhythm

The heart is a muscular organ, roughly the size of your fist, and is made up of four chambers: the left and right atria at the top, and the left and right ventricles at the bottom (figure 1). The heart pumps blood throughout the body through the circulatory system, supplying oxygen and nutrients to tissues and organs, allowing them to work, and removing carbon dioxide and waste products.^1,2

Deoxygenated blood (blood that is low in oxygen) from all around the body flows into the right atrium through the superior and inferior vena cava. The right atrium contracts (squeezes), pushing the blood into the right ventricle, and once the right ventricle is full, it contracts, transferring the blood through the pulmonary arteries into the lungs, where it picks up oxygen (becoming oxygenated blood) and drops off carbon dioxide. The oxygenated blood (blood that is high in oxygen) travels from the lungs through the pulmonary veins into the left atrium and then the left ventricle. When the left ventricle is full, it squeezes, making blood travel through the aorta and release into the rest of the body.¹

The sinus node, a part of the cardiac conduction system, regulates the highly coordinated flow of blood and contraction of chambers. The sinus node serves as the heart's pacemaker, automatically generating a rhythmic electrical signal that causes the heart to contract. Sinus rhythm is a term used to describe the heart’s normal rhythm, which is   60 to 100 beats per minute. Sinus arrhythmia refers to an irregular heart rhythm.³

What is atrial fibrillation?

AF is a type of sinus arrhythmia that occurs when electrical signals within the atria are abnormal and uncoordinated. This causes the atria to fibrillate (quiver) and contract ineffectively, which in turn causes the heart to beat irregularly and too fast (figure 2).⁴

Who can be affected by atrial fibrillation?

AF is one of the most common cardiac rhythm disorders, affecting approximately 33 million people worldwide, with the prevalence of AF predicted to rise to 17.9 million in Europe by 2060. Individuals of European descent have a greater risk of AF compared to Black, Asian, and Hispanic individuals.^5.6

Types of atrial fibrillation

The type of AF you have is classified by the duration and pattern of the episodes experienced:⁴

• Paroxysmal: episodes of AF which stop within 7 days of onset 
• Persistent: episodes of  AF that last longer than 7 days 
• Longstanding persistent AF that is present for a minimum of 12 months 
• Permanent: AF that does not revert to sinus rhythm, as it did not respond to therapies

Lifelong AF is the most frequently diagnosed form of AF, occurring in approximately 40% to 50% of patients. Paroxysmal and persistent AF occur in approximately 20% to 30% of patients, respectively.⁷

Continuous electrical and structural remodelling of the left atrium in patients with paroxysmal  AF can lead to persistent AF. This has been found in 15% of patients at 1-year follow-ups and 36% of patients at 10-year follow-ups.⁸

Causes of persistent atrial fibrillation 

There are many causes of AF, including hypertension, congenital heart disease, heart valve disease, and genetics; however, any condition that leads to oxidative stress, damage, and inflammation can lead to AF.^4,5

Risk factors for persistent atrial fibrillation

Risk factors are characteristics and behaviours that increase the chance of developing a health condition or disease.⁹ The risk factors for  AF include:^6,10

• Advanced age 
• Male sex 
• Smoking 
• Sedentary lifestyle
• Alcohol overconsumption
• Obesity
• Diabetes 
• Obstructive sleep apnea
• Hypertension 

The chance of developing AF is 1 in 5 for people with an optimal risk factor profile (for example, if you never smoked and had a blood pressure lower than 120/80 mmHg), but the chance of developing AF increases to 1 in 3 if you have at least 1 elevated risk factor (for example, if you currently smoke or had a blood pressure greater than 140/90 mmHg).^6,11

Importance of recognising symptoms 

Impact on quality of life

AF can have a significant impact on your quality of life despite not being immediately life-threatening. Studies have shown that people with AF report significantly poorer physical health and functional status.¹² Moreover, increased symptom severity is linked to decreased quality of life and increased risk of hospitalisation.¹³ 

Recognising the symptoms of persistent AF is a part of diagnosis and helps determine what treatment would be most suitable, which may, in turn, help improve quality of life.⁴

Potential complications

 AF can lead to several complications, such as: ^10,14

• Thromboembolism 
• Heart failure 
• Myocardial infarction 
• Stroke 

Recognising the symptoms of persistent  AF and reaching a diagnosis allows you to seek treatment, which can help manage the symptoms of AF and reduce the risk of complications.⁴ 

Key symptoms of persistent atrial fibrillation

While most patients with AF experience symptoms, approximately 15% to 30% of patients diagnosed with  AF do not show any symptoms.¹⁵ 

That being said, some researchers have suggested that people may not know they have AF because they may not be aware of their heart rhythm. It is, therefore, important to be able to recognise the symptoms of  AF for early detection and to avoid the development of sinus node dysfunction, valvular regurgitation, or ventricular dysfunction.⁸

Palpitations

At rest, we are usually unaware of our heartbeat. Palpitations refer to the awareness of your heartbeat and are described by patients as an unpleasant sensation in the chest, neck, or throat. There are different types of palpitations; for example, extrasystolic palpitations, which feel as if your heart is skipping a beat, tachycardiac palpitations involve very rapid heartbeats, and pulsation palpitations involve a strong, pounding heartbeat.¹⁶ 

Fatigue

Fatigue is a state of extreme tiredness and low energy and is one of the most frequently reported symptoms of AF.¹⁷

AF causes the heart to beat irregularly, and this, in turn, reduces the heart’s cardiac output, the volume of blood pumped out by the heart each minute.^18,19 Lower volumes of oxygenated blood reaching the tissues and organs mean less oxygen and fewer nutrients are available to the tissues and organs. Oxygen is needed by cells for aerobic respiration to make ATP (a source of energy). When you do not have enough ATP to meet the demands of your body, it causes fatigue.^20,21

Shortness of breath

Dyspnoea (shortness of breath) is experienced by approximately two-thirds of patients with AF. Similarly to fatigue, AF causes abnormal atrial contraction, which in turn leads to reduced ventricular filling and results in reduced cardiac output. When the heart does not pump blood sufficiently, it leads to fluid accumulation within the lungs, leading to inbreathing.²²

Dizziness

Dizziness includes feeling off-balance, wobbly, disoriented, and faint. Similar to fatigue and dyspnoea, dizziness is caused by reduced blood flow, specifically to the brain (vertebrobasilar insufficiency).²³ In the same vein, AF is associated with syncope (the temporary loss of consciousness) and falls in the elderly.²⁴

When to seek medical attention 

Persistent AF refers to episodes of AF that last longer than 7 days. That being said, if you have any of the mentioned symptoms, you should not wait 7 days before seeking help or guidance from a healthcare professional. 

If you feel that you need to be seen before you speak to your GP and do not think you are having a heart attack, call 111 or visit NHS 111 online to be assessed and directed to the right sources of care for your needs. 

Call emergency services (UK: 999; Europe: 112; USA: 911) if you experience the following symptoms, as you could be experiencing a stroke or heart attack: ^25,26

• Chest pain 
• Sweating 
• Nausea 
• Vomiting 
• Anxiety 
• Weakness (sudden onset, affecting the limbs)
• Face drooping/paralysis 
• Slurred speech 
• Vision problems (e.g., double vision)
• Cognitive impairment (e.g., confusion)

Living with persistent atrial fibrillation 

While  AF can impact your quality of life and lead to complications, it can be managed. 

AF is diagnosed by considering your medical history, findings from a physical examination, electrocardiogram (ECG) test results, and blood test results. Following diagnosis, treatment and management of AF may require cardioversion, medications like beta-blockers, ablation, and pacemaker placement.⁴ 

The specific method of treatment you receive depends on a few factors, including the type of  AF you have. For example, amiodarone is a more effective method of cardioversion for persistent AF than sotalol, which is recommended for paroxysmal AF according to the British National Formulary.^27,28 

Summary 

• The contraction of the heart chambers, blood flow, and subsequent provision of oxygen to the body are controlled by electrical signals sent from the sinus node 
• AF is a common type of irregular heart rhythm involving abnormal and uncoordinated electrical signals within the atria, which causes the atria to quiver 
• Persistent  AF refers to episodes of AF that last longer than 7 days 
• The main symptoms of persistent AF are palpitations, fatigue, shortness of breath, and dizziness
• It is important to be aware of the symptoms of  AF as it can lead to complications like stroke and heart attack