What medications are used to treat tachycardia?

Medications for Tachycardia

Beta blockers, calcium channel blockers (diltiazem, verapamil), and adenosine are the first-line medications for treating most forms of tachycardia, with specific choices depending on the type of tachycardia and patient characteristics. 1

Types of Tachycardia and First-Line Treatments

Supraventricular Tachycardia (SVT)

• Intravenous beta blockers, diltiazem, or verapamil are recommended as first-line treatment for hemodynamically stable patients with SVT 1
• Adenosine is highly effective for acute treatment of AVNRT (atrioventricular nodal reentrant tachycardia) and can also serve as a diagnostic agent 1
• Synchronized cardioversion should be performed for hemodynamically unstable patients when medications fail or aren't feasible 1

Multifocal Atrial Tachycardia (MAT)

• Intravenous metoprolol or verapamil can be useful for acute treatment of MAT 1
• Oral verapamil, diltiazem, or metoprolol is reasonable for ongoing management of recurrent symptomatic MAT 1
• Intravenous magnesium may be helpful even in patients with normal magnesium levels 1

Focal Atrial Tachycardia

• Intravenous beta blockers, diltiazem, or verapamil are useful for acute treatment in hemodynamically stable patients 1
• Synchronized cardioversion is recommended for hemodynamically unstable patients 1

Junctional Tachycardia

• Intravenous beta blockers are reasonable for acute treatment of symptomatic junctional tachycardia 1
• Intravenous diltiazem, procainamide, or verapamil is reasonable for acute treatment when beta blockers are ineffective 1
• Oral beta blockers are reasonable for ongoing management 1

Medication Selection Algorithm

1. Assess hemodynamic stability:

   • If unstable (hypotension, altered mental status, chest pain, acute heart failure): Synchronized cardioversion 1
   • If stable: Proceed with pharmacologic therapy 1

2. For stable SVT:

   • First-line: IV adenosine (for AVNRT), IV beta blockers, IV diltiazem, or IV verapamil 1
   • Contraindications to beta blockers: Severe bronchospasm, decompensated heart failure 1
   • Contraindications to calcium channel blockers: Severe heart failure, hypotension, pre-excited AF 1

3. For MAT:

   • First-line: IV metoprolol or verapamil 1, 2, 3
   • Caution with beta blockers in patients with severe pulmonary disease 1
   • Address underlying conditions (pulmonary disease, electrolyte abnormalities) 1

4. For junctional tachycardia:

   • First-line: IV beta blockers 1
   • Second-line: IV diltiazem or verapamil 1

Specific Medication Dosing and Considerations

• Beta blockers:

  • Metoprolol: 5 mg IV slow bolus (can be repeated if tolerated); 25-50 mg orally for chronic management 1, 2
  • Particularly effective for MAT, with conversion rates of 68-100% 2, 3
  • Use with caution in patients with bronchospasm, decompensated heart failure 1

• Calcium channel blockers:

  • Verapamil: Effective for AVNRT, MAT, and focal AT 1
  • Diltiazem: Similar efficacy to verapamil for most SVTs 1
  • Avoid in patients with severe conduction abnormalities, sinus node dysfunction, or pre-excited AF 1

• Adenosine:

  • First-line for AVNRT diagnosis and treatment 1
  • Short half-life makes it ideal for diagnostic purposes 1

Important Considerations and Pitfalls

• Identify the specific type of tachycardia before selecting medication, as treatment varies by mechanism 1
• Avoid verapamil and diltiazem in patients with ventricular tachycardia misdiagnosed as SVT, as these can cause hemodynamic collapse 1
• Cardioversion is ineffective for automatic forms of focal atrial tachycardia and MAT 1
• Antiarrhythmic medications (class I and III) are generally not helpful for MAT 1
• Treat underlying conditions in MAT, such as pulmonary disease, electrolyte abnormalities, and theophylline toxicity 1
• Monitor for hypotension when administering beta blockers or calcium channel blockers 4
• Recent guidelines have downgraded the recommendations for verapamil/diltiazem in chronic focal AT, acute atrial flutter, and chronic AVNRT 1