SVT









Pathophysiology

History

Symptoms

Physical Exam

Diagnosis

Acute Treatment

  1. ABCs, IV, O2, monitor
  2. HEMODYNAMICALLY UNSTABLE
  3. HEMODYNAMICALLY STABLE
  4. Medical treatment
  5. Wide QRS complex treatment (HR >140, QRS > 120 ms)
  6. Digoxin toxicity treatment (SVT)
Treatment Summary
Treatment Comment
If UNstable
-
Synchronized Cardioversion
Sedate if time allows.
If stable: 
-Vagal maneuvers
-Diving reflex
-Carotid sinus massage

 

Do not perform carotid sinus massage if bruits are present.
Do not perform simultaneous bilateral carotid sinus massage.
First-line pharmacotherapy:
Adenosine, 6 mg (0.1 mg/kg) rapid IV bolus May administer a second dose of 12 milligrams (0.2 mg/kg) if no effect after 2 min.

No proven benefit to more than two doses or >20 mg total.

Second-line pharmacotherapy:
Calcium channel blockers
Diltiazem, 15-20 mg (0.25 mg/kg) IV, followed by a continuous infusion at 4-20 mg/h over 2 min (start at 5 mg/h) May administer a second dose of diltiazem, 25 mg (0.35 mg/kg) IV in 15 min, if needed.
Contraindications to diltiazem use:
  • Hypotension.
  • Severe congestive heart failure.
  • Ventricular tachyarrhythmia.
or  
Verapamil, 2.5 - 5.0 mg IV over 2 min (3 min in older patients) May repeat dose of verapamil, 5-10 mgevery 15 min, up to 20 mg.
Verapamil-induced hypotension may be prevented or treated with calcium chloride, 500-1000 mg, IV every 10 min as needed.
Contraindications to verapamil use:
  • Ventricular tachyarrhythmia.
  • Hypotension.
  • Presence of congestive heart failure.
  • COPD.
ß-Blockers
Metoprolol, 5 mg, IV every 5 min up to 15 mg

 

or

 

Esmolol, 500 mcg/kg IV bolus, over 60 s, followed by an infusion starting at 50 mcg/kg/min May repeat esmolol bolus, 500 mcg/kg, if inadequate response after 2 to 5 min.
Increase infusion rate in increments of 50 mcg/kg/min after each bolus.
or Maximal recommended infusion rate is 300 mcg/kg.
Propranolol, 0.1 mg/kg divided into three doses given slowly at 2 min intervals May repeat dose once.
Contraindications to ß-blocker use:
  • Ventricular tachyarrhythmia.
  • Hypotension.
  • Severe congestive heart failure.
  • History of severe COPD, asthma.

Disposition

  1. Admit
  2. Discharge

Further Management

  1. General measures
  2. Prophylactic Pharmacologic Tx
  3. Single-dose oral Tx (Pill-in-the-pocket)
  4. Long-term Pharmacologic Tx
  5. Procedures