Atrial Fibrillation (AF) — NZ Condition Guide | KiwiMeds

What is Atrial Fibrillation?

Atrial fibrillation (AF or AFib) is the most common heart rhythm disorder, affecting around 40,000–50,000 New Zealanders. In AF, the upper chambers of the heart (atria) beat chaotically and out of sync with the lower chambers (ventricles), causing an irregular, often rapid heartbeat. AF significantly increases the risk of stroke — AF-related strokes tend to be more severe. It is more common with age and is a major cause of hospitalisation in NZ.

Symptoms

Some people with AF have no symptoms at all (silent AF, discovered on an ECG). When symptoms occur, they can include heart palpitations (feeling your heart fluttering, racing, or pounding), shortness of breath, weakness or fatigue, dizziness or lightheadedness, and chest pain or pressure. Symptoms may come and go (paroxysmal AF) or be constant (persistent or permanent AF).

Causes and Risk Factors

AF is caused by abnormal electrical signals in the heart. Risk factors include age (risk doubles each decade after 50), high blood pressure (the most important risk factor), heart disease, heart failure, obesity, diabetes, sleep apnoea, excessive alcohol consumption, overactive thyroid, and smoking. AF can also occur in otherwise healthy people (lone AF).

Diagnosis

AF is diagnosed with an electrocardiogram (ECG) — a test that records the heart’s electrical activity. Because AF may be intermittent, a 24–48 hour Holter monitor (portable ECG worn at home) may be needed. Your GP will also assess for underlying causes with blood tests, echocardiogram (heart ultrasound), and other tests.

Treatment in New Zealand

AF treatment has two main goals: preventing stroke and controlling the heart rate/rhythm. Stroke prevention is the priority — most people with AF are prescribed anticoagulants (blood thinners). The newer direct oral anticoagulants (DOACs) — apixaban (Eliquis) and rivaroxaban (Xarelto) — are now funded by Pharmac and preferred over warfarin for most patients. Rate control medications include beta-blockers (metoprolol) and digoxin. Rhythm control may involve medications or cardioversion (electrical shock to reset the rhythm). Ablation is a procedure that may cure AF in some patients.

NZ-Specific Information

Apixaban and rivaroxaban are now funded by Pharmac, making stroke prevention in AF more accessible and safer than warfarin for most patients. Your GP will calculate your stroke risk using the CHA₂DS₂-VASc score to determine if anticoagulation is recommended. The Heart Foundation of NZ provides support and resources for AF patients.

Frequently Asked Questions

Is AF life-threatening? AF itself is not immediately dangerous, but the associated stroke risk is serious. With appropriate treatment, most people with AF live normal lives. Do I need to restrict my diet on DOACs? Unlike warfarin, DOACs have no dietary restrictions and do not require regular blood tests. Can I drink alcohol with AF? Alcohol can trigger AF episodes and should be minimised.

Supplements That May Support Management

⚠️ Important: The supplements listed below have varying levels of clinical evidence. They are not a substitute for prescribed medications and should only be considered as adjunctive support under the guidance of a qualified healthcare professional. Always inform your GP or pharmacist before commencing any supplement, as interactions with prescribed medicines are possible.

• Magnesium — Magnesium is a physiological calcium antagonist with antiarrhythmic properties. Oral supplementation may help prevent paroxysmal AF in magnesium-deficient individuals, as hypomagnesaemia is a recognised arrhythmia precipitant.
• Omega-3 Fatty Acids (moderate dose) — Moderate-dose omega-3 (1 g/day) has demonstrated AF risk reduction benefits in some analyses. High-dose omega-3 (≥4 g/day, particularly EPA-only) has been associated with increased AF risk. Dietary fish intake appears most beneficial.
• Coenzyme Q10 — CoQ10 at 100–200 mg/day has demonstrated reductions in AF recurrence rate in observational and small trial data, supporting mitochondrial antioxidant function in atrial tissue.
• Vitamin D — Vitamin D deficiency is associated with increased AF risk. Supplementation in deficient individuals is recommended for overall cardiovascular health.

Relevant Vaccinations

Individuals living with atrial fibrillation may benefit from the following vaccinations. Please discuss your vaccination status with your GP or practice nurse, as eligibility and funding through the New Zealand National Immunisation Schedule may apply.

• Influenza (annual) — Influenza can precipitate AF exacerbations and cardiovascular decompensation. Annual vaccination is strongly recommended and funded for people with cardiac conditions.
• Pneumococcal — Pneumococcal pneumonia can trigger AF episodes in susceptible individuals. Vaccination is recommended for people with AF.
• COVID-19 — COVID-19 can trigger new-onset AF and worsen paroxysmal AF. Maintaining vaccination and booster doses is strongly recommended.

Dietary Guidance

Evidence-based dietary modifications play a meaningful role in the management of atrial fibrillation. The following foods are generally recommended as part of a balanced, condition-appropriate diet. A referral to a registered dietitian may be beneficial for personalised nutritional planning.

• Limit caffeine and alcohol — Both are recognised AF triggers. Alcohol is strongly associated with AF (holiday heart syndrome). Reducing or eliminating alcohol is recommended. Moderate caffeine is generally tolerable but reduce if it triggers symptoms.
• Oily fish (2–3 servings per week) — Dietary fish intake is associated with reduced AF risk and provides cardioprotective omega-3 fatty acids.
• Potassium and magnesium-rich foods — Low potassium and magnesium are major AF triggers. Ensure adequate intake through green vegetables, bananas, legumes, nuts, and seeds — under medical guidance given medication interactions.
• Consistent vitamin K intake (if on warfarin) — For people on warfarin, consistent dietary vitamin K from leafy greens is essential for stable INR. Aim for consistent moderate intake rather than avoidance.
• Reduce processed and ultra-processed foods — Ultra-processed food consumption is associated with increased AF risk. A wholefoods dietary approach reduces arrhythmogenic dietary inflammation.

Related Conditions & Medications

Related medications: Metoprolol. Related conditions: Hypertension.