What is the treatment for wide complex tachycardia?

Treatment of Wide Complex Tachycardia

Immediate synchronized cardioversion is the definitive treatment for any hemodynamically unstable wide complex tachycardia, regardless of the underlying rhythm. 1, 2, 3

Initial Assessment and Stabilization

Determine hemodynamic stability first – this single decision point drives all subsequent management:

• Unstable patients (hypotension, altered mental status, shock, chest pain, acute heart failure) require immediate synchronized cardioversion without delay for pharmacologic therapy 1, 2, 3
• Sedate conscious patients if time permits (consider etomidate 0.2-0.3 mg/kg IV given hypotension) 3
• Apply defibrillator pads immediately and maintain continuous cardiac monitoring 3
• Establish two large-bore IV lines and obtain a 12-lead ECG, but do not delay cardioversion to obtain these 3

Management Algorithm for Stable Wide Complex Tachycardia

Step 1: Determine Rhythm Regularity and Morphology

For regular monomorphic wide complex tachycardia:

• Procainamide is the first-line agent for hemodynamically stable monomorphic VT in patients without severe heart failure or acute MI 1
• Amiodarone 150 mg IV over 10 minutes is recommended for patients with hemodynamically stable monomorphic VT, particularly those with severe heart failure or acute MI 1, 4
• Sotalol 1.5 mg/kg IV over 5 minutes may be considered for stable sustained monomorphic VT, including patients with acute MI, but avoid if QT is prolonged 1, 5
• IV adenosine may be considered for undifferentiated regular stable wide complex tachycardia – it is relatively safe, may convert the rhythm to sinus, and helps diagnose the underlying rhythm 1, 2

Step 2: Special Considerations for Polymorphic Wide Complex Tachycardia

Never give adenosine for irregular or polymorphic wide complex tachycardia 2

For polymorphic VT with long QT syndrome (torsades de pointes):

• IV magnesium is the primary treatment for both acquired and familial long QT-associated polymorphic VT 1, 2
• Add overdrive pacing (atrial or ventricular) or IV isoproterenol when polymorphic VT is accompanied by bradycardia or appears precipitated by pauses 1, 2
• IV beta-blockers for familial long QT syndrome 1
• Avoid isoproterenol in familial long QT syndrome 1

For polymorphic VT without long QT syndrome:

• IV beta-blockers may be effective for ischemic VT or catecholaminergic VT 1, 2
• Consider isoproterenol for non-ischemic cases 1

Critical Pitfalls to Avoid

Never use calcium channel blockers (verapamil, diltiazem) for wide complex tachycardia unless definitively proven to be supraventricular tachycardia – they can cause hemodynamic collapse in ventricular tachycardia 2, 3

Do not delay cardioversion in unstable patients to attempt pharmacologic conversion or obtain additional diagnostic studies 2, 3

When in doubt, treat as ventricular tachycardia – this is the safest approach since VT represents the majority of wide complex tachycardias and misdiagnosis can be fatal 6, 7, 8

Avoid beta-blockers in hypotensive states 3

Metabolic and Electrolyte Considerations

Rapidly correct electrolyte abnormalities (particularly potassium, magnesium, and calcium) in all patients with wide complex tachycardia 2, 3

Check stat electrolytes and correct abnormalities immediately, as metabolic causes do not make the arrhythmia more benign 2, 3

Post-Stabilization Management

All patients with wide complex tachycardia require ICU/CCU admission and immediate cardiology/electrophysiology consultation 3

Consider electrophysiology study and possible ablation once stabilized 3

Most patients require amiodarone therapy for 48-96 hours, though it may be safely administered for longer periods if necessary 4