What is the treatment for wide complex tachycardia (WCT)?

From the Guidelines

The treatment for wide complex tachycardia should prioritize immediate synchronized cardioversion for unstable patients and electrical cardioversion as the first-line approach for stable patients, as recommended by the most recent guidelines 1.

Key Considerations

• The patient's hemodynamic stability is crucial in determining the treatment approach for wide complex tachycardia.
• For unstable patients with signs of poor perfusion, immediate synchronized cardioversion at 100-200 joules is recommended.
• For stable patients, the first step is to determine if the rhythm is ventricular tachycardia (VT) or supraventricular tachycardia (SVT) with aberrancy.

Treatment Options

• If VT is suspected, intravenous amiodarone 150 mg over 10 minutes, followed by an infusion of 1 mg/min for 6 hours, then 0.5 mg/min maintenance, is the first-line medication 1.
• Alternative options include procainamide (20-50 mg/min until arrhythmia suppression, hypotension, QRS widening, or maximum 17 mg/kg) or lidocaine (1-1.5 mg/kg IV bolus, followed by 0.5-0.75 mg/kg every 5-10 minutes if needed, maximum 3 mg/kg) 1.
• For SVT with aberrancy, adenosine (6 mg rapid IV push, followed by 12 mg if needed) may be attempted.
• Beta-blockers like metoprolol (5 mg IV over 2-5 minutes, may repeat twice) or calcium channel blockers like diltiazem (0.25 mg/kg IV over 2 minutes) can be used for certain types of SVT.

Additional Recommendations

• Underlying causes such as electrolyte abnormalities, drug toxicity, or myocardial ischemia should be addressed.
• Prompt cardiology consultation is advised, especially if the diagnosis is uncertain or the patient is not responding to initial treatment.

From the Research

Treatment Approach

The treatment of wide complex tachycardia (WCT) depends on various factors, including patient stability, regularity of the rhythm, and QRS morphology 2.

Patient Stability

• Unstable patients require immediate cardioversion 3.
• Stable patients can be treated with lidocaine or procainamide 3.
• Adenosine can be used when wide QRS SVT is the diagnosis, and it also has been used as a diagnostic aid to identify dysrhythmias 3.

Diagnostic Considerations

• The history, physical examination, and ECG provide information required to arrive at the correct diagnosis 3.
• ECG analysis is the most useful process in differentiating SVT and VT 3.
• Characteristics suggestive of VT include evidence of AV dissociation, QRS duration of longer than 0.16 seconds, and QRS axis between -90 degrees +/- 180 degrees 3.

Treatment Options

• Monomorphic WCT should be presumed to be ventricular tachycardia and treated as such when in doubt 2.
• Magnesium sulfate may be useful in refractory cases of VT and torsades de pointes 3.
• Chronic treatment of patients prone to VT may include complex pharmacotherapy and AICDs 3.
• A simplified and practical approach to the initial evaluation and management of wide-complex tachycardia can be useful in real-life settings 4.

Special Considerations

• The identification of whether WCT has a ventricular or supraventricular origin is critical because the treatment for each is different, and improper therapy may have potentially lethal consequences 5.
• A stepwise approach to the management of WCT in relatively stable adult patients can help in the diagnosis and differentiation of ventricular tachycardia from supraventricular tachycardia with a wide QRS complex on standard 12-lead electrocardiography 5.