Atrial Fibrillation vs. SVT: Key Differences in Diagnosis and Management

Both are supraventricular tachyarrhythmias, but mechanisms, stroke risk, and long-term management differ significantly.

Comparison

Feature	Atrial Fibrillation (AFib)	Supraventricular Tachycardia (SVT)
Mechanism	Chaotic atrial electrical activity; irregular ventricular response	Re-entry circuit (AVNRT, AVRT) or focal atrial tachycardia; regular, rapid
Heart Rate	Irregularly irregular; often 100–170 bpm	Regular; typically 150–250 bpm
ECG Hallmark	No P waves; fibrillatory baseline; irregular R-R	Narrow complex tachycardia; retrograde P waves (AVNRT) or short RP (AVRT)
Stroke Risk	High (CHA₂DS₂-VASc guides anticoagulation)	Very low (no anticoagulation needed)
Common Triggers	Alcohol, sleep apnea, hypertension, thyroid disease, post-op	Caffeine, stress, alcohol, exertion, WPW syndrome
Acute Management	Rate control (β-blocker, CCB, digoxin) ± rhythm control ± anticoagulation	Vagal maneuvers → adenosine → cardioversion if unstable
Long-Term Options	Anticoagulation, rate/rhythm control, catheter ablation	Catheter ablation (curative >95% for AVNRT/AVRT)

When to Seek Care

• New-onset palpitations, syncope, chest pain, dyspnea
• Known arrhythmia with worsening symptoms
• AFib: assess stroke risk urgently

Shared Lifestyle Modifications

• Limit alcohol/caffeine; treat sleep apnea; manage stress; regular exercise; weight optimization.