If you experience palpitations or an irregular heartbeat, get an ECG; if diagnosed with atrial fibrillation, consult a doctor about anticoagulants to prevent stroke, and do not substitute aspirin

Atrial fibrillation (AFib) causes the heart's upper chambers to beat chaotically, allowing blood to pool and form clots; if a clot travels to the brain, it triggers a devastating ischemic stroke. Taking doctor-prescribed anticoagulants reduces the risk of stroke by roughly 60% and lowers overall mortality by about 30%. Antiplatelet drugs like aspirin reduce stroke risk by only about 20% and cannot serve as an effective substitute. In national surveys, only a tiny fraction of high-risk patients with AFib were taking anticoagulants.

A standard ECG costs just a few dozen yuan (under $10). Warfarin is inexpensive but requires regular blood tests (INR monitoring) to adjust the dosage. Newer direct oral anticoagulants (DOACs) do not require routine blood monitoring but are more expensive. The primary challenge is maintaining daily adherence even in the absence of symptoms, and remembering to inform dentists and surgeons that you take anticoagulants before any invasive procedure.

AFib causes chaotic atrial quivering, leading to blood stasis and thrombus formation. The most common symptoms are palpitations, exertional fatigue, and chest discomfort, though approximately 25% of individuals report no noticeable symptoms. A single-lead ECG recording lasting >=30 seconds or a standard 12-lead ECG lasting >=10 seconds provides definitive diagnosis. A 2007 meta-analysis pooled 29 randomized controlled trials with 28,044 participants: compared to control/placebo, dose-adjusted warfarin reduced stroke by 64% (95% CI 49%–74%), whereas antiplatelet therapy (such as aspirin) reduced stroke by only 22% (95% CI 6%–35%). In direct head-to-head trials, warfarin reduced stroke by an additional 39% compared to antiplatelets. Absolute increase in major extracranial hemorrhage was under 0.3% per year. A Cochrane review evaluating 2,313 individuals with no prior stroke found warfarin lowered all-cause mortality by roughly 30% (OR 0.69, 95% CI 0.50–0.94). Four landmark trials totaling 71,683 patients comparing direct oral anticoagulants (DOACs) to warfarin demonstrated DOACs further reduced stroke and systemic embolism by 19% (RR 0.81, 95% CI 0.73–0.90) and all-cause mortality by 10% (RR 0.90, 95% CI 0.85–0.95), with a 52% reduction in intracranial hemorrhage (RR 0.48), despite a 25% increase in gastrointestinal bleeding (RR 1.25). Aspirin cannot replace anticoagulation: in 5,599 patients unsuitable for warfarin, apixaban reduced stroke and systemic embolism by 55% compared to aspirin (HR 0.45, 95% CI 0.32–0.62) with no significant difference in major bleeding (1.4% vs 1.2% per year; HR 1.13, 95% CI 0.74–1.75). In the BAFTA trial of 973 seniors aged >=75, warfarin reduced fatal or disabling stroke, intracranial hemorrhage, or arterial embolism by 52% compared to aspirin (RR 0.48, 95% CI 0.28–0.80) with similar extracranial bleeding (1.4% vs 1.6% per year). Chinese 2023 AFib guidelines utilize the CHA2DS2-VASc-60 score (congestive heart failure, hypertension, age >=65 [2 points], diabetes, prior stroke/TIA [2 points], vascular disease, age 60–64, female sex [1 point each]): oral anticoagulation is strongly recommended for males with score >=2 and females with score >=3, and considered for males with score 1 and females with score 2 after weighing bleeding risk. Guidelines explicitly advise against antiplatelet monotherapy for AFib stroke prevention. ACC/AHA 2023 guidelines emphasize anticoagulation decisions depend on thromboembolic risk, regardless of whether AFib is paroxysmal, persistent, or permanent, and bleeding scores should be used to address modifiable bleeding risks rather than inappropriately withhold anticoagulation. National epidemiological surveys (2014–2016) in China of adults aged >=45 found an AFib prevalence of 1.8% (~7.9 million individuals), with awareness at 78.3% in urban areas but only 35.3% in rural areas; among high-risk patients, only 6.0% were receiving anticoagulation. A 2020–2021 nationwide survey found 43.8% of identified AFib cases were newly detected, and among previously diagnosed individuals, only 32.1% were using anticoagulants (19.8% in rural areas).

Controverted in terms of asymptomatic population screening, though anticoagulation following diagnosis is undisputed. Evidence remains insufficient regarding whether asymptomatic individuals should undergo targeted mass screening. The USPSTF (2022) concluded evidence is insufficient to assess the balance of benefits and harms of routine screening. The Swedish STROKESTOP trial in 75–76 year-olds found a modest 4% composite reduction in stroke, mortality, and severe bleed after ~7 years, just reaching statistical significance. The Danish LOOP study in 70–90 year-olds with implantable loop recorders detected AFib in 31.8% vs 12.2%, yet saw no significant difference in stroke rates. Chinese 2023 guidelines suggest pulse palpation or opportunistic ECG during routine clinic visits for seniors aged >=65. Thus, individuals with symptoms must be evaluated, and seniors aged >=65 should ask their doctor to check their pulse during visits, but buying dedicated commercial consumer screening monitors is unnecessary. Once on anticoagulants, do not self-administer NSAIDs like ibuprofen without medical supervision, as noted in Chapter 34, Rule 3. Anticoagulants must be taken long-term; never stop them simply because you feel fine, as described in Chapter 16, Rule 1. Hypertension is also a key risk factor, as detailed in Chapter 1, Rule 7. Individuals with AFib do not necessarily need to eliminate coffee, as discussed in Chapter 2, Rule 26. If sudden facial drooping or unilateral limb weakness develops, call emergency services immediately regardless of medication status, as detailed in Chapter 13, Rule 3. Primary beneficiaries are yourself and elderly family members.

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