What is the treatment for tachycardia?

Treatment for High Pulse (Tachycardia)

The treatment for tachycardia depends critically on whether the patient is hemodynamically unstable (requiring immediate synchronized cardioversion) versus stable (where treatment is determined by whether the rhythm is narrow-complex or wide-complex). 1, 2

Immediate Assessment: Stable vs. Unstable

• Unstable patients require immediate synchronized cardioversion regardless of tachycardia type—do not delay for pharmacologic attempts. 3, 1, 2
• Unstable signs include hypotension, altered mental status, chest pain, acute heart failure, or shock. 3
• For stable patients, obtain a 12-lead ECG to determine if the QRS complex is narrow (<0.12 seconds) or wide (≥0.12 seconds). 3

Narrow-Complex Tachycardia (Stable Patients)

First-Line Approach

• Begin with vagal maneuvers (Valsalva, carotid massage), which succeed in approximately 28% of supraventricular tachycardia (SVT) cases. 2
• If vagal maneuvers fail, adenosine is first-line: 6 mg rapid IV bolus followed by saline flush, then 12 mg if no response after 1-2 minutes. 3, 1, 2
• Adenosine terminates approximately 95% of atrioventricular nodal reentrant tachycardia (AVNRT) cases. 2
• Avoid adenosine in severe bronchial asthma and irregular/polymorphic wide-complex tachycardia. 3

Alternative Agents if Adenosine Fails

• IV beta-blockers (metoprolol 5 mg slow IV bolus) or IV calcium channel blockers (diltiazem 5-10 mg over 60 seconds or verapamil 5-10 mg over 60 seconds) are reasonable alternatives. 3, 1
• Critical pitfall: Never give both IV beta-blockers and calcium channel blockers together due to risk of severe hypotension and bradycardia. 3

Special Case: Multifocal Atrial Tachycardia (MAT)

• First-line treatment is addressing the underlying condition (pulmonary disease, hypomagnesemia, theophylline toxicity). 3
• IV metoprolol or verapamil can be used for acute rate control. 3, 1
• IV magnesium may be helpful even with normal magnesium levels. 3, 1
• Cardioversion is ineffective for MAT. 3, 2

Wide-Complex Tachycardia (Stable Patients)

Critical Decision Point

• Assume wide-complex tachycardia is ventricular tachycardia (VT) until proven otherwise and treat accordingly. 2
• Never use verapamil or diltiazem for wide-complex tachycardia—these can cause hemodynamic collapse if the rhythm is VT. 1, 2

Treatment Options

• For monomorphic VT: Amiodarone combined with beta-blockers is first-line (150 mg IV over 10 minutes, repeat as needed up to 2.2 g/24 hours). 3, 2
• Procainamide is recommended for stable monomorphic VT without severe heart failure or acute MI (20-30 mg/min up to 12-17 mg/kg, then 1-4 mg/min infusion). 3, 2
• Sotalol (1.5 mg/kg over 5 minutes) is also effective but avoid in prolonged QT interval. 3
• Lidocaine is less effective than procainamide, sotalol, and amiodarone—consider it second-line (1-1.5 mg/kg IV bolus, then 1-4 mg/min infusion). 3

Ongoing Management Considerations

For Recurrent SVT

• Oral beta-blockers are first-line for chronic therapy, with oral diltiazem or verapamil as reasonable alternatives. 1
• Catheter ablation should be considered for patients with frequent recurrences or drug intolerance. 3, 4

For Atrial Fibrillation with Rapid Ventricular Response

• Beta-blockers or diltiazem are drugs of choice for acute rate control. 1, 2
• Digoxin should be avoided for chemical cardioversion—it has no role and may perpetuate atrial fibrillation. 2, 5
• Digoxin should not be used for multifocal atrial tachycardia. 5

Critical Pitfalls to Avoid

• Never use calcium channel blockers in Wolff-Parkinson-White syndrome with atrial fibrillation—this can cause increased conduction down the accessory pathway leading to ventricular fibrillation. 5
• Avoid adenosine in pre-excited atrial fibrillation (atrial fibrillation with WPW)—it may trigger 1-15% conversion to atrial fibrillation. 3
• Do not use verapamil/diltiazem if beta-blockers have already been given due to additive negative inotropic and chronotropic effects. 1
• Cardioversion is ineffective for automatic tachycardias (focal atrial tachycardia, MAT). 3, 2