Atrial Fibrillation

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia — an irregular, chaotic electrical rhythm in the upper heart chambers (atria). Instead of contracting in an organised way, the atria quiver, causing an irregularly irregular pulse. The principal danger is stroke: stagnant blood in the left atrial appendage forms clots that can embolise to the brain. AF causes 20–30% of all ischaemic strokes. Every patient with AF requires CHA₂DS₂-VASc stroke risk scoring and anticoagulation where indicated.

The CHA₂DS₂-VASc score calculates annual stroke risk in non-valvular AF patients. Risk factors and their points: Heart failure (1), Hypertension (1), Age ≥75 (2 — double weight), Diabetes (1), Stroke/TIA history (2 — double weight), Vascular disease (1), Age 65–74 (1), Female sex (1). Maximum score = 9. Men with score ≥2 and women with score ≥3 should receive anticoagulation. Prior stroke or TIA (S₂ = 2 points) alone mandates anticoagulation regardless of other factors.

Rate control slows the ventricular rate (target <110 bpm at rest) using beta-blockers or diltiazem — the patient remains in AF but symptoms are controlled. Rhythm control attempts to restore and maintain normal sinus rhythm via cardioversion, antiarrhythmic drugs, or catheter ablation. EAST-AFNET 4 (NEJM 2020) showed that early rhythm control in patients with cardiovascular risk factors reduced CV death, stroke, and hospitalisation by 21% versus rate control alone — supporting earlier rhythm control in suitable patients.

DOACs (apixaban, rivaroxaban, dabigatran, edoxaban) are the preferred anticoagulants for non-valvular AF — safer and more effective than warfarin for most patients. They are at least as effective at stroke prevention, with significantly lower intracranial haemorrhage risk. ARISTOTLE showed apixaban reduced stroke by 21%, all-cause mortality by 11%, and major bleeding by 31% versus warfarin. DOACs do not require INR monitoring. Warfarin remains indicated for mechanical heart valves and significant mitral stenosis.

Yes — paroxysmal AF is defined as episodes that start and stop spontaneously within 7 days, often lasting minutes to hours. Many patients with paroxysmal AF experience symptoms intermittently, sometimes going weeks or months between episodes. These brief episodes carry the same stroke risk as persistent AF if CHA₂DS₂-VASc score is elevated, so anticoagulation decisions are based on risk factors, not on whether the AF is constant or intermittent. Holter monitoring is essential to capture paroxysmal episodes — a single normal ECG does not rule out AF. Approximately 30% of patients with paroxysmal AF will progress to persistent or permanent AF within 5 years.

Common triggers for AF episodes include excessive alcohol consumption (particularly binge drinking — the 'holiday heart syndrome'), caffeine in sensitive individuals, sleep deprivation, physical or emotional stress, dehydration, and electrolyte imbalances. Fever, acute infections (especially pneumonia), and post-surgical states can also precipitate AF. Obstructive sleep apnoea is a powerful and under-recognised trigger — treating sleep apnoea can significantly reduce AF burden. Some patients identify specific triggers through symptom diaries. Avoiding known triggers, maintaining good sleep hygiene, and managing stress can reduce episode frequency but does not eliminate the need for anticoagulation if indicated.

Catheter ablation (pulmonary vein isolation) is more effective than antiarrhythmic medication at maintaining sinus rhythm and reducing AF recurrence — particularly in patients with paroxysmal AF and structurally normal hearts. The EAST-AFNET 4 trial showed that early rhythm control (including ablation) reduced cardiovascular death, stroke, and hospitalisation by 21% compared with rate control alone. Ablation is especially beneficial for patients who are intolerant of or unresponsive to antiarrhythmic drugs, those with heart failure and AF (CASTLE-AF showed a 38% reduction in death and HF hospitalisation), and younger patients who prefer a curative approach. However, ablation does not eliminate the need for anticoagulation in patients with elevated stroke risk.

Yes — with appropriate management, most patients with AF can lead a full, active, and normal life. The key components are: stroke prevention with anticoagulation when indicated (DOACs are safe and convenient with no need for regular blood monitoring), rate or rhythm control to manage symptoms, and treatment of underlying conditions such as hypertension, sleep apnoea, and obesity. Many athletes, public figures, and active seniors live well with AF. Regular exercise is encouraged, though competitive athletes should undergo cardiac evaluation. Driving is generally permitted if symptoms are controlled. The most important message is that AF is a manageable chronic condition — not a life sentence.