1

Assess appropriateness for clinical condition. Heart rate typically beats/min if tachyarrhythmia.

2

Identify and treat underlying cause

Maintain patent airway; assist breathing as necessary
Oxygen (if hypoxemic)
Cardiac monitor to identify rhythm; monitor blood pressure and oximetry

4

Synchronized cardioversion

Consider sedation
If regular narrow complex, consider adenosine

3

Persistent tachyarrhythmia causing:

Hypotension?
Acutely altered mental status?
Signs of shock?
Ischemic chest discomfort?
Acute heart failure?

Yes

No

End

6

IV access and 12-lead ECG if available
Consider adenosine only if regular and monomorphic
Consider antiarrhythmic infusion
Consider expert consultation

7

IV access and 12-lead ECG if available
Vagal maneuvers
Adenosine (if regular)
-Blocker or calcium channel blocker
Consider expert consultation

5

Wide QRS? 0.12 second

Wide QRS? 0.12 second

Yes

No

Doses/Details

Synchronized cardioversion:

Initial recommended doses:

Narrow regular: 50–100 J
Narrow irregular: 120–200 J biphasic or 200 J monophasic
Wide regular: 100 J
Wide irregular: defibrillation dose (not synchronized)

Narrow regular: 50–100 J
Narrow irregular: 120–200 J biphasic or 200 J monophasic
Wide regular: 100 J
Wide irregular: defibrillation dose (not synchronized)

Adenosine IV dose:

First dose: 6 mg rapid IV push; follow with NS flush.
Second dose: 12 mg if required

Antiarrhythmic Infusions for Stable Wide-QRS Tachycardia

Procainamide IV dose: 20–50 mg/min until arrhythmia suppressed, hypotension ensues, QRS duration increases >50%, or maximum dose 17 mg/kg given. Maintenance infusion: 1–4 mg/min. Avoid if prolonged QT or CHF.

Amiodarone IV dose: First dose: 150 mg over 10 minutes. Repeat as needed if VT recurs. Follow by maintenance infusion of 1 mg/min for first 6 hours.

Sotalol IV dose: 100 mg (1.5 mg/kg) over 5 minutes. Avoid if prolonged QT.