What is the appropriate management of tachyarrhythmia?

Tachyarrhythmia Management

For acute supraventricular tachycardia (SVT), adenosine is the drug of choice after vagal maneuvers fail, while hemodynamically unstable patients require immediate synchronized cardioversion. 1, 2

Acute Management Algorithm

Step 1: Assess Hemodynamic Stability

• Unstable patients (hypotension, altered mental status, chest pain, heart failure): Proceed directly to synchronized cardioversion 2
• Stable patients: Continue with stepwise approach below

Step 2: Initial Interventions for Stable Patients

Vagal Maneuvers (First-Line)

• Perform Valsalva maneuver: patient bears down against closed glottis for 10-30 seconds (≥30-40 mm Hg pressure) in supine position 2
• Alternative: Apply ice-cold wet towel to face or perform carotid sinus massage (after confirming no bruit) for 5-10 seconds 2
• Success rate approximately 28% when switching between techniques 2

Step 3: Pharmacological Treatment by QRS Width

Narrow-QRS Tachycardias (AVNRT, AVRT, focal AT)

• Adenosine remains the drug of choice with 90-95% conversion rate 1, 2
• Beta-blockers have increased strength of recommendation for narrow-QRS tachycardias and AVRT 1
• Verapamil and diltiazem are downgraded but still options 1
• Do NOT use: Amiodarone or digoxin (no longer recommended) 1

Wide-QRS Tachycardias

• Adenosine has increased strength of recommendation even for wide-QRS tachycardias 1
• Procainamide is downgraded but remains an option 1
• Do NOT use: Sotalol, lidocaine, or amiodarone (no longer recommended) 1
• Critical caveat: Never use verapamil in wide-QRS tachycardias of unknown etiology (Class III recommendation) 1

Step 4: Special Situations

Pre-Excited Atrial Fibrillation (WPW with AF)

• Hemodynamically unstable: Immediate synchronized cardioversion 2
• Hemodynamically stable: Ibutilide or IV procainamide 2
• Absolute contraindications: Digoxin, beta-blockers, diltiazem, verapamil, and amiodarone—these may precipitate ventricular fibrillation by increasing ventricular rate 1

Atrial Flutter

• Ibutilide recommended for cardioversion 1
• Do NOT use: Digitalis for acute treatment; flecainide/propafenone contraindicated 1

Inappropriate Sinus Tachycardia/POTS

• Ivabradine alone or with beta-blockers (though not EMA-approved for this indication) 1
• Verapamil/diltiazem no longer recommended 1

Critical Pitfalls to Avoid

1. Never use AV nodal blockers in pre-excited AF—this includes digoxin, beta-blockers, diltiazem, verapamil, and amiodarone, as they may cause ventricular fibrillation 1

2. Avoid flecainide/propafenone in:

   • Left bundle branch block
   • Ischemic or structural heart disease
   • Atrial flutter cardioversion
   • ACHD patients with ventricular dysfunction 1

3. Have cardioversion equipment ready when administering adenosine, as it may precipitate AF with rapid ventricular response 2

4. Pregnancy considerations: Avoid all antiarrhythmics in first trimester if possible; if necessary, use beta-1-selective blockers (not atenolol) or verapamil in non-WPW patients, or flecainide/propafenone in WPW without structural heart disease 1

Key Evidence Changes from 2019 ESC Guidelines

The 2019 ESC guidelines represent a major shift toward simplification, with many previously used drugs now contraindicated or downgraded 1. The "pill-in-the-pocket" approach is no longer recommended for AVRT or AVNRT 1. This reflects a move toward catheter ablation as definitive therapy rather than chronic pharmacological management for most SVTs.