Wide complex tachycardia resident survival guide

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Rim Halaby, M.D. [2]

Definition

Wide complex tachycardia is characterized by a heart rate more than 100 beats per minute associated with a QRS interval of more than 120 ms. When wide complex tachycardia is present, it is important to determine whether the tachycardia is of a supraventricular or a ventricular origin.

Management

Diagnostic Approach

Characterize the symptoms: ❑ Asymptomatic ❑ Palpitations ❑ Dyspnea ❑ Fatigue ❑ Chest discomfort ❑ Lightheadedness ❑ Syncope Characterize the timing of the symptoms: ❑ Onset ❑ Duration ❑ Frequency

Identify possible triggers: ❑ Infection ❑ Caffeine ❑ Alcohol ❑ Nicotine ❑ Recreational drugs ❑ Hypovolemia ❑ Hyperthyroidism

❑ Examine the patient

❑ Order an EKG

Therapeutic Approach

Wide complex tachycardia QRS ≥ 120ms

Do the following simultaneously: - Assess and support ABC's as needed - Give oxygen - Monitor ECG, BP, oxymetry - Identify and treat reversible causes

Is the patient stable? Unstable signs include: - Chest pain - Congestive heart failure - Hypotension - Loss of consciousness - Seizures

Yes

No

Is the rhythm regular?

Immediate synchronized cardioversion -Establish IV access - Give IV sedation if the patient is conscious - Consider expert consultation

Regular rhythm

Irregular rhythm

Ventricular tachycardia or uncertain rhythm?

SVT with aberrancy?

Afib with aberrancy?

Pre-excited Afib (Afib + WPW)?

Recurrent polymorphic VT?

Torsade de pointes?

- Give amiodarone 150 mg IV over 10 min - Repeat amiodarone as needed for a maximal dose of 2.2g/24h - Prepare for elective synchronized cardioversion

- Give adenosine 6 mg rapid IV push - If no conversion give 12 mg IV push - May repeat 12 mg dose once

- Consider expert consultation - Control rate e.g diltiazem or beta blockers Use beta blockers with caution in pulmonary diseases or CHF

- Consider expert consultation - Avoid AV nodal blocking agents e.g adenosine, digoxin, diltiazem and verapamil - Consider amiodarone 150 mg IV over 10 min

Consider expert consultation

Load with Magnesium 1-2 g over 5-60 min, then infusion

Algorithm based on the 2003 ACLS guidelines for the management of tachycardia.

Do's

• Refer the patient to an arrhythmia specialist in case the tachycardia causes syncope or dyspnea as well as the wide complex tachycardia is of unknown cause.
• Place an ambulatory 24 hour Holter when the tachycardia is frequent and transient.