Introduction

Atrial fibrillation (AF)  is the most common cardiac arrhythmia, characterised by rapid and irregular contractions of the upper chambers of the heart, the atria.⁵ It affects millions worldwide and significantly increases the risk of stroke, heart failure, and other cardiovascular complications.¹ Doctors usually classify AF based on how long the episodes last and how they stop. The current categories include newly diagnosed AF, paroxysmal AF (PAF), persistent AF (PersAF), long-standing persistent AF, and permanent AF. But because the symptoms can vary or overlap, it’s sometimes hard to fit someone neatly into one category until their condition becomes clearer.⁷

Studies using heart-monitoring devices have shown that this classification system doesn’t always match how the condition behaves over time. Also, many people with AF don’t feel any symptoms, which can make the classification less useful.

Understanding the different types of AF is crucial for effective management. Two key subtypes- persistent and paroxysmal AF- differ primarily in their duration and response to treatment. While paroxysmal AF is self-terminating and lasts less than seven days, persistent AF requires medical intervention to restore normal rhythm.²

This discussion aims to outline the key differences between persistent and paroxysmal AF, focusing on their duration, clinical implications, and management strategies. Recognising these distinctions is essential for optimising treatment and improving patient outcomes.

Definition and duration

Paroxysmal atrial fibrillation

Paroxysmal Atrial Fibrillation (PAF) is a type of irregular heart rhythm where the heart suddenly beats in a fast and disorganised way, but the episodes come and go. These irregular heartbeats start and stop on their own and usually last less than seven days—most often less than 48 hours. This happens because of erratic electrical signals in the upper chambers of the heart (the atria), which prevent them from contracting properly. As a result, the heart can’t pump blood efficiently, which may increase the risk of clots forming and lead to complications, such as strokes. PAF may be triggered by things such as stress, drinking alcohol, too much caffeine, or even poor sleep.⁵ People with PAF may not notice any symptoms at all, while others might feel their heart racing (palpitations), become dizzy, feel breathless, or unusually tired. Although these episodes are temporary, they can become more frequent over time and may lead to more persistent forms of atrial fibrillation if not managed properly.

Persistent atrial fibrillation

Persistent Atrial Fibrillation is a type of abnormal heart rhythm where the irregular heartbeat lasts for more than seven days or fails to stop without medical intervention, such as medication or electrical cardioversion (a controlled electric shock to the heart), to restore a normal rhythm. Unlike paroxysmal AF, which resolves on its own, persistent AF tends to linger and places increased strain on the heart. Ongoing episodes can trigger an inflammatory response, leading to the activation of myofibroblasts, specialised cells that contribute to tissue repair. These cells release inflammatory and fibrotic substances, including transforming growth factor-β, platelet-derived growth factor, and galectin-3, which promote the formation of scar tissue (fibrosis) within the heart. This structural remodelling can make it harder for the heart to maintain a normal rhythm and increase the likelihood of further episodes. Persistent AF is often associated with underlying heart disease or structural abnormalities and carries a higher risk of progressing to permanent atrial fibrillation if not properly managed.

Differences in management

Paroxysmal AF treatment

• Lifestyle modifications (e.g., reducing caffeine/alcohol, stress management)
• Medications: Beta-blockers (https://www.nhs.uk/conditions/beta-blockers/), calcium channel blockers, or antiarrhythmic drugs (e.g., flecainide)
• Anticoagulation may be necessary based on stroke risk assessment determined by the CHA₂DS₂-VASc score(https://www.nhs.uk/conditions/anticoagulants/)

Persistent AF treatment

• More aggressive management is required
• Electrical cardioversion is often used to restore a normal rhythm
• Long-term use of antiarrhythmic drugs or rate control medications (e.g., beta-blockers, digoxin)
• Consideration of catheter ablation if medications fail
• Higher likelihood of requiring long-term anticoagulation due to increased stroke risk

Prognosis and long-term considerations

• Paroxysmal AF can progress to persistent AF if not managed properly
• Persistent AF increases the risk of complications such as heart failure and stroke
• Regular monitoring and follow-ups are essential for both types

Conclusion

Paroxysmal atrial fibrillation (AF) is characterised by intermittent episodes of irregular heart rhythm that typically resolve on their own within 48 hours (5), although they may last up to a week. In contrast, persistent AF is a more prolonged condition (6), where the abnormal rhythm persists for longer than a week and often requires medical intervention, such as medication or electrical cardioversion, to restore normal heart rhythm. Early diagnosis of AF is crucial as it allows for timely and appropriate management, which can significantly improve patient outcomes. Treatment strategies should be tailored to the individual, considering specific risk factors such as age, underlying heart conditions, and the presence of other health issues (7). A personalised approach ensures that patients receive the most effective care, reducing the risk of complications like stroke and heart failure while also improving the quality of life for those affected by AF.

Summary

• Atrial fibrillation (AF) is an irregular heart rhythm that can vary in duration and severity
• Paroxysmal AF involves brief, sudden episodes that usually resolve within 24 hours but may last up to a week. These episodes can occur with or without symptoms and may happen repeatedly. When this alternates with a slower-than-normal heartbeat, it is known as tachy-brady syndrome
• Persistent AF lasts for more than seven days and may require treatment to restore a normal rhythm, although it can occasionally return to normal on its own
• Long-term persistent AF continues for over a year without improving, despite ongoing attempts to manage the condition
• Permanent AF is diagnosed when medical efforts to restore a normal rhythm are no longer effective, and the condition is accepted as chronic

FAQs

What is atrial fibrillation (AF)?

A common heart rhythm disorder where the atria beat irregularly and rapidly.

What is paroxysmal atrial fibrillation?

Episodes of irregular heart rhythm that last less than 24 hours but can last up to a week.

Can paroxysmal AF lead to more serious forms?

Yes, it can progress to persistent or permanent AF over time.

What is tachy-brady syndrome?

A condition where AF alternates with slow heart rhythms, causing symptoms like dizziness.

What is persistent atrial fibrillation?

AF that lasts for more than seven days and may require treatment to return to normal rhythm.

What is long-term persistent AF?

AF lasting over a year without improvement despite treatment.

What is permanent atrial fibrillation?

AF that does not improve, even after attempts to restore normal rhythm.