Paroxysmal supraventricular tachycardia

(Redirected from PSVT)

SVT terminology can be confusing, as some references consider SVT to be any rhythm originating above the ventricles (e.g. sinus tachycardia, MAT, atrial flutter, atrial fibrillation, PSVT, etc). As these entities have their own specific articles and treatment, only paroxysmal supraventricular tachycardia links here.


  • Most common dysrhythmia in children and young, otherwise healthy patients
  • Also known as PSVT and frequently referred to just as SVT
  • Subtypes include AV nodal reentrant tachycardia (AVNRT) and AV reentrant tachycardia (AVRT)

Clinical Features

Differential Diagnosis

Narrow-complex tachycardia

Wide-complex tachycardia

Assume any wide-complex tachycardia is ventricular tachycardia until proven otherwise (it is safer to incorrectly assume a ventricular dysrhythmia than supraventricular tachycardia with abberancy)

^Fixed or rate-related



PSVT at ~180 bpm
Symptoms Sinus tachycardia SVT
History Volume loss Sudden onset
Physical Exam Dehydrated CHF-like
^Heart Rate (generally) <180 >180
Variability Yes No

^In infants HR cuttoff = 220

  • ECG findings
    • P-waves
      • Sinus tachycardia - may be seen before QRS complexes
      • SVT - either p-waves not seen OR retrograde p-waves
    • Signs with no actionable clinical relevance, unless they persist after conversion:
      • ST depressions in any lead
      • ST elevation in aVR
      • SVT is very rarely isolated manifestation of ACS and ST changes usually resolve after PSVT is appropriately treated
  • Consider PSVT underlying causes to include[1]:
  • Troponins are not indicated in patients without significant risk factors for CAD[2]
Termination of PSVT following adenosine

Unstable Management

  • Synchronized cardioversion 0.5-1.0 J/kg
  • Pediatrics: synchronized cardioversion at 0.5-1 J/kg
    • If unsuccessful, increase to 2 J/kg
  • Consider sedation prior to cardioversion only if it will not significantly delay the procedure

Stable Management

Vagal maneuvers

  • Modified Positional Valsalva more successful than traditional Valsalva maneuver[3]
  • Carotid sinus massage for 15 seconds [4])
    • Auscultate for bruits prior to performing
    • Massage one side at a time
    • Do not attempt in elderly patients or patients with known carotid artery disease or risk factors
  • Mammalian diving reflex (pediatrics)
    • Most effective in infants
  • Apply cold ice pack over face for 15-30 seconds, covering nose
    • Be conscientious of infants as obligate nasal breathers



  • 6mg rapid IV push (1st dose)
    • Warn patient of sense of discomfort during transient sinus pause immediately following dose
    • Ensure rapid push is through a large bore IV with proximity to the heart (left side antecubital preferred) as half-life of adenosine is less than 10 seconds [5]
    • Follow rapid push with 20cc rapid saline flush, consider use of Y-tubing or 3-way stopcock
    • Raise left arm above head immediately after push to facilitate rapid delivery to myocardium
  • If unsuccessful, push 12mg (2nd dose)[6]
  • If unsuccessful, consider repeat bolus of 12mg (3rd dose) (to a max of 30mg)
    • Some literature to support 3rd dose of 18mg[7]
  • If still unsuccessful, consider calcium channel blocker as below
    • May have higher conversion rates and patient comfort in appropriate patients


  • 0.1mg/kg (1st dose) rapid IV push as above
  • If unsuccessful, attempt second 0.1 mg/kg dose or escalate immediately to 0.2mg/kg (2nd dose) IV push

Other Considerations

  • Relatively contraindicated in asthmatics due to increased bronchoconstriction
  • Patients taking methylxanthines (eg caffeine, theophylline) may require higher dose
  • Consider initial adult dose of 3mg, if:[8]
    • Central line
      • Decreased transit time to heart
    • Heart transplant
      • Relative sensitivity of denervated transplanted hearts
        • Note that full dose may be used safely, but initial half-dose is reasonable [9]
    • Taking carbamazepine or dipyridamole

Calcium-channel blockers


  • Diltiazem 0.25mg/kg IV over 2min
    • May give 0.35mg/kg IV if inadequate response after 15min
    • If IV bolus worked start IV infusion at 5–20mg/hr
    • A slow infusion of 2.5 mg/min to a maximum of 50 mg is also an option
      • In this trial 50% had converted by 12 mg and 75% had converted by 18 mg[10]
    • Contraindications: Hypotension, CHF, any suspicion of VT
    • Consider calcium gluconate premedication OR afterwards if BP falls
  • Phase 2 trial completed on intranasal CCB (Etripamil)[11]
    • High conversion rate (65 to 95%)
    • Median time to conversion 3 minutes


  • Verapamil 1-4 mg/kg q8hrs (only if >12 months old)[12]
  • May cause significant hypotension in infants



  • Metoprolol 5mg IV q5min x 3; give 50mg PO if IVP effective
  • Esmolol 500mcg/kg IV over 60sec
    • May give repeat bolus if inadequate response after 2-5min
    • If effective start infusion at 50mcg/kg/min (titrate up to 300mcg/kg/min)



  • Most can be discharged
    • Avoid stimulants, sympathomimetics
    • Consider low dose beta-blocker prescription, beta-1 specific (atenolol, metoprolol)
    • Follow up with primary care provider if first episode
    • Follow up with cardiology if recurrent episodes
  • A retrospective review of 111 patients found[13]:
    • 79 (71%) were discharged from the ED
      • 3 (4%) in this group had recurrent SVT after discharge
      • None had an unstable event
    • 32 (29%) were admitted to the hospital
      • 6 of the 32 (19%) had recurrent PSVT in the hospital
    • Recurrence more likely to occur in older patients and those with CVD

See Also

External Links

Amal Mattu ECG Case: Feb 26 2012


  1. Gugneja M et al. eMedicine. Paroxysmal Supraventricular Tachycardia. Dec 30, 2015.
  2. Bukkapatnam et al. Relationship of myocardial ischemia and injury to coronary artery disease in patients with supraventricular tachycardia. Am J Cardiol. 2010 Aug 1;106(3):374-7.
  3. Appelboam A. et al. Postural modification to the standard Valsalva manoeuvre for emergency treatment of supraventricular tachycardias (REVERT): a randomised controlled trial fulltext
  4. Appelboam, A, et al. Randomised Evaluation of modified Valsalva Effectiveness in Re-entrant Tachycardias (REVERT) study. BMJ, 2014; 4(3):e004525.
  6. 2015 ACLS
  7. Weismuller P et al. Terminating supraventricular tachycardia with adenosine--comparing the effectiveness of 12mg and 18mg. Dtsch Med Wochenschr. 2000 Aug 18;125(33):961-9.
  8. ACLS Algorithms.
  9. Flyer, J. et al. (2017) Prospective study of adenosine on atrioventricular nodal conduction in pediatric and young adult patients after heart transplant. Circulation, April 27
  10. Lim SH, Anantharaman V, Teo WS, Chan YH. Slow infusion of calcium channel blockers compared with intravenous adenosine in the emergency treatment of supraventricular tachycardia. Resuscitation. 2009 May;80(5):523-8. doi: 10.1016/j.resuscitation.2009.01.017. Epub 2009 Mar 3.
  11. Stambler, B. S., Dorian, P., Sager, P. T., Wight, D., Douville, P., Potvin, D., … Plat, F. (2018). Etripamil Nasal Spray for Rapid Conversion of Supraventricular Tachycardia to Sinus Rhythm. Journal of the American College of Cardiology, 72(5), 489–497.
  12. 12.0 12.1 12.2 Salerno, J et al. Supraventricular Tachycardia Arch Pediatr Adolesc Med. 2009;163(3):268-274.
  13. Luber S, Brady WJ, Joyce T, et al. Paroxysmal supraventricular tachycardia: outcome after ED care. Am J Emerg Med. 2001; 19(1):40-42.