Paroxysmal supraventricular tachycardia: Difference between revisions

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**SVT - either p-waves not seen OR retrograde p-waves
**SVT - either p-waves not seen OR retrograde p-waves
*Generally, troponins are not indicated in pts without significant risk factors for CAD<ref>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.</ref>
*Generally, troponins are not indicated in pts without significant risk factors for CAD<ref>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.</ref>
*Consider SVT underlying causes to include<ref>Amal Mattu. Mattu ECG Case: Feb 26 2012. umemergencymed. Published Apr 9, 2012. https://www.youtube.com/watch?v=XWypPq-33Tg.</ref><ref>Gugneja M et al. eMedicine. Paroxysmal Supraventricular Tachycardia. Dec 30, 2015. http://emedicine.medscape.com/article/156670-overview#a5.</ref>:
**Drug toxicity, especially caffeine, stimulants, digoxin
**EtOH
**Thyroid disease
**Electrolyte abnormality
**Hypoxia, pulmonary embolism
**Pre-existing heart disease (prior MI, MVP, pericarditis)
**However, SVT is very rarely isolated manifestation of ACS
***Does not require routine MI rule out
***Evaluate signs and symptoms as if there is no dysrhythmia


==Management==
==Management==

Revision as of 02:02, 8 March 2016

SVT terminology can be confusing, as some references consider SVT to be any rhythm originating above the ventricles (i.e. 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.

Background

  • Also known as PSVT and frequently referred to just as SVT
  • AV nodal reentrant tachycardia (AVNRT) and AV reentrant tachycardia (AVRT) are subtypes of PSVT
  • Most common dysrhythmia in children
  • Infants: poor feeding, tachypnea, and irritability

Clinical Features

Differential Diagnosis

Palpitations

Diagnosis

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

^In infants HR cuttoff = 220

  • P-waves[1]
    • Sinus tachycardia - may be seen before QRS complexes
    • SVT - either p-waves not seen OR retrograde p-waves
  • Generally, troponins are not indicated in pts without significant risk factors for CAD[2]
  • Consider SVT underlying causes to include[3][4]:
    • Drug toxicity, especially caffeine, stimulants, digoxin
    • EtOH
    • Thyroid disease
    • Electrolyte abnormality
    • Hypoxia, pulmonary embolism
    • Pre-existing heart disease (prior MI, MVP, pericarditis)
    • However, SVT is very rarely isolated manifestation of ACS
      • Does not require routine MI rule out
      • Evaluate signs and symptoms as if there is no dysrhythmia

Management

Termination of PSVT following adenosine

Unstable

  • Synchronized cardioversion 0.5-1.0 J/kg
  • Pediatrics: cardioversion at 0.5-1 J/kg. If unsuccessful, increase to 2 J/kg
  • Consider giving sedation prior to cardioversion (unless in emergent situation)

Stable

Vagal maneuvers

  • Pediatrics: often successful with ice application to face
  • Carotid sinus massage (ideal duration of 15 seconds[5])
    • Auscultate to r/o bruits in carotid artery before performing
    • Perform ONE side at a time
  • Valsalva maneuver (ideal duration of 10 seconds) and may be modified to be followed by laying the patient supine and performing passive leg raise to increase efficacy[6]

Adenosine

  • 6mg IVP; 12mg IVP (if initial dose failed)
  • Contraindicated in asthmatics
  • Some literature to support 3rd dose of 18 mg if 12 mg fails[7]
  • May decrease initial dose to 3 mg if[8]:
    • Central line
    • Heart transplant
    • Taking carbamazepine or dipyridamole

Calcium-channel blockers

  • Diltiazem 15–20mg IV over 2min
    • May give 25mg IV if inadequate response after 15min
    • If IV bolus worked start IV infusion at 5–20mg/hr
    • Contraindications: Hypotension, CHF, any suspicion of VT
    • Consider calcium gluconate premedication OR afterwards if BP falls
  • Beta-blockers (don't combine with CCBs)
    • 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)
    • Contraindicated in asthmatics

Disposition

  • Most can be discharged
  • A retrospective review of 111 patients found[9]:
    • 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 ain older patients and those with CVD

See Also

References

  1. ↑ Amal Mattu. Mattu ECG Case: Feb 26 2012. umemergencymed. Published Apr 9, 2012. https://www.youtube.com/watch?v=XWypPq-33Tg.
  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. ↑ Amal Mattu. Mattu ECG Case: Feb 26 2012. umemergencymed. Published Apr 9, 2012. https://www.youtube.com/watch?v=XWypPq-33Tg.
  4. ↑ Gugneja M et al. eMedicine. Paroxysmal Supraventricular Tachycardia. Dec 30, 2015. http://emedicine.medscape.com/article/156670-overview#a5.
  5. ↑ Appelboam, A, et al. Randomised Evaluation of modified Valsalva Effectiveness in Re-entrant Tachycardias (REVERT) study. BMJ, 2014; 4(3):e004525.
  6. ↑ Appelboam A. et al. Postural modification to the standard Valsalva manoeuvre for emergency treatment of supraventricular tachycardias (REVERT): a randomised controlled trial fulltext
  7. ↑ Weismuller P et al. Terminating supraventricular tachycardia with adenosine--comparing the effectiveness of 12 mg and 18 mg. Dtsch Med Wochenschr. 2000 Aug 18;125(33):961-9.
  8. ↑ ACLS Algorithms. https://acls-algorithms.com/acls-drugs/acls-and-adenosine/.
  9. ↑ Luber S, Brady WJ, Joyce T, et al. Paroxysmal supraventricular tachycardia: outcome after ED care. Am J Emerg Med. 2001; 19(1):40-42.
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