• Rule out life-threatening causes of tachycardia: Hypoxia, ischemia, and acidosis.
• Review the EKG to assess wave morphology
  • Narrow-QRS complex (SVT) tachycardia has a QRS <0.12 seconds. Assess rate, regularity, and P-wave presence and morphology.
  • Wide-QRS complex tachycardia has a QRS interval 0.12 seconds
• Sinus tachycardia
  • Review recent events (intubation, blood loss, incision or surgical stimulation, movement, other vital signs) and medications administered
• Wide complex tachycardia: To distinguish between ventricular and SVT (with aberrations) origin:
  • Maneuvers (i.e., carotid sinus pressure and Valsalva maneuver) – the response of the arrhythmia to maneuvers may provide insight to the mechanism of the wide complex tachycardia (SVTs tend to stop with this maneuver while ventricular arrhythmias do not).
  • Diagnostic pharmacologic interventions:
    • SVT: Verapamil, diltiazem, adenosine, or beta-blockers will terminate PSVT and slow SVT
    • VT: Procainamide, sotalol, or amiodarone may terminate the rhythm. Adenosine will not stop or slow down.

Laboratory tests

• Arterial blood gas to assess for hypoxia, acidosis, and anemia
• Plasma potassium and magnesium concentrations. Hypokalemia and hypomagnesemia both predispose to the development of ventricular tachyarrhythmias. Hyperkalemia can cause a wide-QRS complex rhythm with the loss of a detectable P-wave, although this usually has a slow rate (so-called "sinoventricular rhythm"). In patients taking digoxin, quinidine, or procainamide, consider measuring plasma concentrations to assist in evaluating possible toxicity.
• Chest x-ray (cardiomegaly or evidence of previous cardiac surgery)

• If the patient is hemodynamically unstable (hypotension, acutely altered mental status, signs of shock, chest pain, acute heart failure), proceed immediately to appropriate electrical shock therapy (synchronized cardioversion or defibrillation for VF):
  • Synchronized cardioversion initial recommended dose:
    • Narrow regular: 50–100 J
    • Narrow irregular (e.g., atrial fibrillation): 120–200 J biphasic or 200 J monophasic
    • Wide regular: 100 J
    • Wide irregular (defibrillation dose – NOT synchronized): 360 J monophasic or 120–200 J biphasic
    • Pediatric: Initial dose of 2–4 J/kg. Subsequent energy levels may be considered, but should not exceed 10 J/kg.
  • Not effective for multifocal and focal atrial tachycardia
• Polymorphic VT requires immediate defibrillation with the same strategy used for VF. Prevention of recurrent polymorphic VT may be performed with magnesium, pacing, and/or sotalol, amiodarone, or procainamide.
• Stable ST. Treatment should be aimed at the underlying cause. In patients at risk for myocardial ischemia or demonstrating hemodynamic compromise, consider rate control with beta-blockers.
• Regular, stable narrow complex tachycardia
  • Vagal maneuvers
  • Consider: Beta-blockers or calcium channel blockers
  • Amiodarone may be considered in patients with congestive heart failure
  • Adenosine 6 mg IV followed by a 20 mL saline flush; may repeat with a 12 mg rapid IV push after 1–2 minutes.
• Stable wide-QRS tachycardia:
  • Procainamide, amiodarone, sotalol

• Patients who develop sustained and/or nonsustained VT during the perioperative period should be referred to a cardiologist for further evaluation, including an evaluation of their ventricular function and screening for heart ischemia.
• Several studies suggest beta-blocker therapy can reduce mortality and the incidence of cardiovascular complications (including the development of arrhythmias) during surgery, and for up to 2 years afterward.
• for long-term treatment of SVTs: AV nodal blocking agents (e.g., verapamil, diltiazem, beta-blockers, digoxin), amiodarone, and disopyramide may be started by cardiology.
• Radiofrequency ablation is a safe, effective, and cost-effective method for suppressing SVT.

1. Neumar Link MS , Atkins DL , Passman RS , et al. Part 6: Electrical therapies: Automated external defibrillators, defibrillation, cardioversion, and pacing: 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation. 2010;122(18 Suppl 3):S706–S719.
2. Neumar RW , Otto CW , Link MS , et al. Part 8: Adult advanced cardiovascular life support: 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation. 2010;122(suppl 3):S729–S767.
3. Reising S , Kusumoto F , Goldschlager N. Life-threatening arrhythmias in the intensive care unit. J Intensive Care Med. 2007;22(1):3–13.
4. Zipes DP , Camm AJ , Borggrefe M , et al. ACC/AHA/ESC 2006 guidelines for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death: A report of the American College of Cardiology/American Heart Association Task force and the European Society of Cardiology Committee for Practice Guidelines: Developed in collaboration with the European Heart Rhythm Association and the Heart Rhythm Society. Circulation. 2006;114(10):e385–484.

• When the heart rate is <150/min, it is unlikely that symptoms of instability are caused primarily by the tachycardia unless there is impaired ventricular function or structure (e.g., outflow tract obstruction, aortic stenosis, mitral stenosis, etc).
• When cardiac function is poor, cardiac output can be dependent on a rapid heart rate. In such compensatory sinus tachycardias, stroke volume is limited; thus, decreases in the heart rate can be detrimental (e.g., induction of general anesthesia with cardiac tamponade).
• If the tachycardia is suspected to be the cause of acute altered mental status, ischemic chest discomfort, acute heart failure, hypotension, or other signs of shock, the patient should receive immediate synchronized cardioversion.
• If there is any doubt whether monomorphic or polymorphic VT is present in the unstable patient, provide high-energy defibrillation without waiting for detailed analysis of the rhythm.
• Active tachyarrhythmias for which the patient should undergo evaluation and treatment before noncardiac surgery:
  • Symptomatic ventricular arrhythmias
  • Supraventricular arrhythmias (including atrial fibrillation) with uncontrolled ventricular rate (heart rate >100 bpm at rest)
  • Newly recognized VT.