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.

Causes

Life Threatening Causes

Life-threatening causes include conditions which may result in death or permanent disability within 24 hours if left untreated. Wide complex tachycardia can be a life-threatening condition and must be treated as such irrespective of the causes.

Common Causes

• Atrial fibrillation with aberrancy
• Atrial fibrillation with pre-excitation
• Superior ventricular tachycardia (SVT) with aberrancy
• Ventricular tachycardia

Management

Shown below is an algorithm depicting the management of wide complex tachycardia according to the 2003 ACC/AHA/ESC guidelines for the management of patients with supraventricular arrhythmias and the 2005 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care.

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

Wide complex tachycardia QRS ≥ 120ms

Do the following simultaneously: - Assess and support ABC's as needed - Give oxygen - Monitor ECG, BP, oxymetry -Establish IV access - 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 ❑ 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

❑ Attempt vagal maneuvers ❑ 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

Antiarrhythmics

Shown below is a table summarizing the choices of the antiarrhythmic drugs for the different types of tachycardia according to the 2003 ACC/AHA/ESC guidelines for the management of patients with supraventricular arrhythmias.

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. Treat the patient as having a ventricular tachycardia when the diagnosis of supraventricular tachycardia can not be made. Suspect ventricular tachycardia in a patient with wide complex tachycardia and previous myocardial infarction or a history of structural heart disease. References Management of wide complex tachycardia SVT + BBB ▸ Vagal maneuvers OR ▸ Adenosine OR ▸ Verapamil OR ▸ Diltiazem SVT or atrial fibrillation + Preexcitation ▸ Flecainide OR ▸ Ibutilide OR ▸ Procainamide OR ▸ Cardioversion Wide QRS tachycardia of unknown origin ▸ Procainamide OR ▸ Sotalol OR ▸ Amiodarone OR ▸ Cardioversion Wide QRS tachycardia of unknown origin + poor LV function ▸ Amiodarone OR ▸ Cardioversion