265.1 🎓 醫孞生版

265.1.0.1 📌 䞀頁重點

265.1.0.1.1 Epidemiology
  • ~ 38 million people globally with AF
  • Lifetime risk ~ 25% (1 in 4 adults > 40 yr)
  • 5× higher stroke risk vs normal sinus rhythm
  • Mortality increased 1.5-2×
  • Aging population drives incidence
265.1.0.1.2 Classification (2023 ACC/AHA)
265.1.0.1.2.1 Stages
  • Stage 1 (At Risk): HTN + DM + obesity + OSA + smoking + family hx + ASCVD (modifiable risk factors)
  • Stage 2 (Pre-AF): structural abnormalities + atrial flutter (without overt AF)
  • Stage 3 (AF):
    • 3A Paroxysmal: self-terminating < 7 days
    • 3B Persistent: > 7 days; requires cardioversion to restore SR
    • 3C Long-standing persistent: > 1 year continuous
    • 3D Successful ablation: AF eliminated
  • Stage 4 (Permanent): rhythm control abandoned
265.1.0.1.3 Pathophysiology
  • Re-entrant + automatic focal triggers in atria
  • Pulmonary veins = key triggering source (especially paroxysmal AF)
  • Atrial fibrosis (substrate)
  • Inflammation (PUFA, hsCRP)
  • Aging
  • HTN-induced atrial remodeling
  • Sleep apnea + obesity + alcohol contribute
265.1.0.1.4 Causes / Risk Factors
265.1.0.1.4.1 Modifiable
  • Hypertension (#1 modifiable)
  • Obesity (BMI ≥ 30 doubles risk)
  • Diabetes mellitus
  • Sleep apnea (OSA major contributor)
  • Alcohol (binge + chronic)
  • Smoking
  • Physical inactivity OR excessive endurance exercise (paradoxical)
  • Coronary artery disease
  • Heart failure
  • Valvular heart disease (mitral)
  • Thyroid disease (hyperthyroidism)
265.1.0.1.4.2 Non-Modifiable
  • Age
  • Genetics
  • Family history
  • Congenital heart disease
265.1.0.1.4.3 Triggers (Acute)
  • Alcohol (especially binge — “holiday heart”)
  • Caffeine excess
  • Stress
  • Acute illness (sepsis, surgery, PE, MI)
  • Electrolyte abnormality
265.1.0.1.5 Diagnosis
  • ECG: irregularly irregular rhythm; no discrete P waves; fibrillatory baseline
  • Ambulatory monitoring (Holter, event monitor, ILR) for paroxysmal
  • Wearables (Apple Watch, KardiaMobile) — FDA-approved AF detection algorithms
265.1.0.1.6 Symptoms
  • Often asymptomatic (40%+ — silent AF)
  • Palpitations
  • Dyspnea
  • Fatigue
  • Decreased exercise tolerance
  • Chest discomfort
  • Lightheadedness
  • Syncope (especially elderly with rapid response or pre-excited AF)
  • Stroke (presenting feature) — devastating
265.1.0.1.7 Management Pillars (4 Pillars 2024)
  1. Rate Control + Rhythm Control
  2. Anticoagulation for Stroke Prevention
  3. Risk Factor Modification
  4. Comorbid Disease Management
265.1.0.1.8 Stroke Risk Assessment
265.1.0.1.8.1 CHA2DS2-VASc Score
Factor Points
C Congestive HF 1
H Hypertension 1
A2 Age ≥ 75 2
D Diabetes 1
S2 Prior stroke / TIA 2
V Vascular disease (MI, PAD, aortic plaque) 1
A Age 65-74 1
Sc Sex female (when scored ≥ 2) 1
265.1.0.1.8.2 Threshold for Anticoagulation
  • Men: CHA2DS2-VASc ≥ 1 (consider) or ≥ 2 (recommended)
  • Women: CHA2DS2-VASc ≥ 2 (consider) or ≥ 3 (recommended)
  • 2024 ESC: ≥ 1 in men, ≥ 2 in women → consider anticoagulation
265.1.0.1.9 Bleed Risk Assessment
265.1.0.1.9.1 HAS-BLED Score
Factor Points
H Hypertension uncontrolled 1
A Abnormal renal/liver function 1 each (max 2)
S Stroke 1
B Bleeding history / predisposition 1
L Labile INR (on warfarin) 1
E Elderly > 65 1
D Drugs (antiplatelet, NSAID) or alcohol 1 each (max 2)
  • Score ≥ 3 = high bleeding risk
  • Doesn’t preclude anticoagulation; addresses modifiable factors
265.1.0.1.10 Anticoagulation Options (2023 ACC/AHA + 2024 ESC)
265.1.0.1.10.1 DOAC (Direct Oral Anticoagulant) — Preferred
  • Apixaban (Eliquis): 5 mg PO bid (reduce to 2.5 mg if 2 of 3: age ≥ 80, weight ≀ 60 kg, Cr ≥ 1.5)
  • Rivaroxaban (Xarelto): 20 mg PO daily (15 mg in CrCl 30-50)
  • Edoxaban (Savaysa): 60 mg PO daily (30 mg in CrCl 15-50)
  • Dabigatran (Pradaxa): 150 mg PO bid (110 if age > 80 or bleeding risk)
  • Reversal agents: idarucizumab (dabigatran), andexanet alfa (apixaban + rivaroxaban + edoxaban)
265.1.0.1.10.2 Warfarin
  • Reserved for:
    • Mechanical heart valve (DOACs contraindicated — RE-ALIGN trial)
    • Moderate-severe mitral stenosis
    • Other specific scenarios (severe renal failure, antiphospholipid syndrome with high stroke risk, drug interactions)
  • INR goal: 2.0-3.0
  • Monitor INR
265.1.0.1.10.3 Left Atrial Appendage Occlusion (LAA Closure)
  • Watchman (most common; FDA 2015)
  • Amulet (Abbott; FDA 2021)
  • For patients with contraindication to long-term anticoagulation (severe bleeding history, falls, mechanical issue)
  • Reduces stroke risk equivalent to anticoagulation
  • Procedure: catheter-based transseptal puncture; deploy device in LAA
  • Short-term anticoagulation post (typically 6 weeks - 6 months) then aspirin
265.1.0.1.11 Rate vs Rhythm Control
265.1.0.1.11.1 Rate Control (Traditional Approach)
  • β-blockers (metoprolol, bisoprolol, carvedilol) — first-line
  • Non-dihydropyridine CCB (verapamil, diltiazem) — alternative or combination
  • Digoxin (less commonly; especially in HFrEF)
  • Goal: resting HR < 80 bpm; exercise HR < 110 bpm (lenient ≀ 110 at rest in some)
  • Amiodarone in severe rate refractory
265.1.0.1.11.2 Rhythm Control (Increasingly Earlier)
  • Cardioversion + antiarrhythmic drugs + catheter ablation
  • CASTLE-AF: catheter ablation superior to medical therapy in HFrEF + AF
  • CABANA: ablation vs medical equivalent (some subgroups ablation better)
  • EAST-AFNET 4: early rhythm control improves outcomes in recently diagnosed AF
  • Trend toward earlier rhythm control + ablation especially in younger + symptomatic + HF
265.1.0.1.12 Cardioversion
265.1.0.1.12.1 Electrical (Synchronized)
  • Sedation + synchronized cardioversion
  • 100-200 J biphasic
  • Anticoagulation requirements:
    • AF < 48 hr + low risk: cardioversion without anticoagulation OR DOAC pre-procedure
    • AF > 48 hr or unknown duration:
      • 3-4 weeks therapeutic anticoagulation pre-cardioversion + 4 weeks post
      • OR TEE to exclude LAA thrombus + cardioversion + 4 weeks anticoagulation post
265.1.0.1.12.2 Pharmacologic
  • Flecainide (no structural heart disease)
  • Propafenone (no structural)
  • Amiodarone (preferred in HF + structural)
  • Ibutilide (acute; ICU monitoring)
  • Vernakalant (acute; not in some countries)
265.1.0.1.13 Antiarrhythmic Drugs (Maintenance)
  • Amiodarone: most effective but toxic (thyroid, pulmonary, hepatic, ocular, dermatologic)
  • Flecainide / Propafenone: no structural heart disease (Class IC)
  • Sotalol: β-blocker + Class III; structural OK but QT monitoring
  • Dofetilide: requires inpatient initiation
  • Dronedarone: less effective than amiodarone but better safety profile (no thyroid/pulm toxicity)
265.1.0.1.14 Catheter Ablation
265.1.0.1.14.1 Indications
  • Symptomatic paroxysmal AF (1st-line increasingly)
  • Persistent AF
  • Failed antiarrhythmic drug
  • HFrEF + AF (CASTLE-HF)
  • Recently diagnosed AF (EAST-AFNET 4)
265.1.0.1.14.2 Technique
  • Pulmonary vein isolation (PVI) — cornerstone
  • Radiofrequency (point-by-point) or cryoablation (balloon)
  • 70-90% success for paroxysmal (single procedure)
  • Lower for persistent (60-80%)
  • Repeat ablation if recurrence (often)
265.1.0.1.14.3 Complications
  • Pericardial effusion / tamponade
  • Stroke (rare; periprocedural anticoagulation critical)
  • Atrial-esophageal fistula (rare but fatal)
  • Phrenic nerve injury (cryoablation)
  • Pulmonary vein stenosis (rare with modern techniques)
265.1.0.1.15 Risk Factor Modification
265.1.0.1.15.1 Lifestyle
  • Weight loss (RACE trial: 10% weight loss reduces AF burden)
  • Exercise (moderate)
  • Alcohol reduction (NEJM 2020 — abstinence trial)
  • OSA treatment (CPAP)
  • Blood pressure control
  • Diabetes control
265.1.0.1.16 Special Situations
265.1.0.1.16.1 AF + HF
  • Diuretics + ACEi/ARB/ARNI/SGLT2i for HF
  • Rate control with β-blocker (not amiodarone first-line)
  • Rhythm control improving outcomes (CASTLE-HF — ablation)
265.1.0.1.16.2 AF Post-MI
  • DAPT + anticoagulation balancing
  • Brief DAPT + DOAC often preferred
265.1.0.1.16.3 AF + Valvular Disease
  • Mechanical valve: warfarin
  • Moderate-severe MS: warfarin
  • Other valvular: DOAC OK
265.1.0.1.16.4 AF + Pregnancy
  • Limited DOAC data
  • Warfarin contraindicated 1st + 3rd trimester
  • LMWH preferred for anticoagulation
  • Procainamide, digoxin, β-blocker for rate / rhythm control