In the management of PSVT
(paroxysmal supraventricular tachycardia)











 
Is it PSVT?

  • PSVT is often seen in young adults.
  • They may report palpitations, pounding in the chest, chest pressure or pain, weakness, shortness of breath, or dizziness.
  • The heart rate can range from 150-250 bpm.
PSVT is a reentrant tachycardia. In its most common form, reentry occurs within the AV node itself.

The ECG shows a regular rhythm of 150 beats per minute or higher, with a narrow QRS complex.

 

Normal ECG Strip

PSVT ECG Strip

PSVT also can be associated with reentry to the AV node via an accessory pathway, such as in Wolff-Parkinson-White syndrome.

back to top


Treatment protocol

Once PSVT has been diagnosed, appropriate vagal maneuvers-- such as Valsalva maneuvers--should be considered if clinically appropriate.

If vagal maneuvers are unsuccessful or not appropriate, Adenocard is indicated.

back to top


Dosing & administration of Adenocard

Adenocard (adenosine injection) should be given as a rapid intravenous (IV) bolus. It should be administered either directly into a vein, or if given into an IV line, it should be given as close to the patient as possible and followed by a rapid saline flush.

Indication

Conversion to sinus rhythm of PSVT, including that associated with accessory bypass tracts (Wolff-Parkinson-White syndrome).

Mechanism of action

Adenocard is adenosine injection, an endogenously produced nucleoside, which acts directly on the AV node to slow electrical conduction and interrupt reentry pathways.

The drug of choice for PSVT

Adenocard is recommended by the American Heart Association's ACLS guidelines as the drug of choice, for narrow complex tachycardia in adults1 and pediatric2 patients.

Dosing:

Adult Patients

  • Start with a rapid 6-mg IV bolus.
  • If PSVT persists, give a rapid 12-mg IV bolus.
  • If required, give a second rapid 12-mg IV bolus.
  • If the arrhythmia persists after the second 12-mg IV bolus, re-evaluate your diagnosis.

Pediatric Patients

Pediatric patients with a body weight of <50 kg

  • Start with a rapid 0.05 to 0.1 mg/kg IV bolus.
  • If PSVT persists, give incremental doses of IV bolus.
  • If required, repeat the IV bolus dose until a single dose of 0.3 mg/kg is used.

Pediatric patients with a body weight of > 50 kg

  • Administer with the adult dosing schedule.

Administration

  • If using a peripheral line, inject as close to the patient as possible.
  • Inject fast, 1-2 seconds.
  • Follow each injection with rapid saline flush.

With this protocol, Adenocard has been shown to convert PSVT to sinus rhythm in 93.4% of cases, with a mean time to conversion of 31.1 seconds.3

back to top


Adverse effects

After injection, some patients may feel a few seconds of discomfort. The most common symptoms may include facial flushing, shortness of breath and chest pressure. Patients generally tolerate these effects very well, especially if you prepare them by explaining that the sensations will probably disappear quickly. These are generally self-limiting and resolve within a few seconds.

Less common adverse effects include transient or prolonged asystole, varying degrees of AV block, premature ventricular contractions, premature atrial contractions, and bradycardia.

Usually, no systemic hemodynamic effects are associated with the recommended doses of Adenocard.

Adenocard has been administered in the presence of other cardiovascular agents such as:

  • ACE inhibitors
  • beta-blockers
  • calcium channel blockers
  • quinidine

Adenocard should be used with caution with agents that slow AV node conduction. Dipyridamole may potentiate the effects of Adenocard. Caffeine and theophylline/aminophylline antagonize actions of Adenocard.

See full prescribing information provided on this Web site for a complete listing of contraindications, warnings, precautions, and adverse reactions.

back to top


If it's not PSVT

If, after the last bolus dose, conversion has not occurred, the dysrhythmia is probably not PSVT. In such cases, Adenocard may reduce ventricular rate without conversion.3

back to top

References:
1. The American Heart Association in Collaboration With the International Liaison Committee on Resuscitation (ILCOR). Guidelines 2000 for cardiopulmonary resuscitation and emergency cardiovascular care. Part 6: advanced cardiovascular life support. Circulation. 2000;102(Suppl I):I-158-I-165.

2. The American Heart Association in Collaboration With the International Liaison Committee on Resuscitation (ILCOR). Guidelines 2000 for cardiopulmonary resuscitation and emergency cardiovascular care. Part 10: pediatric advanced life support. Circulation. 2000;102(Suppl I):I-291-I-342.

3. DiMarco JP, Miles W, Akhtar M, et al. Adenosine for paroxysmal supraventricular tachycardia: dose ranging and comparison with verapamil. Assessment in placebo-controlled, multicenter trials. Ann Intern Med. 1990;113:104-110.

 

Ansyr® is a registered trademark of Abbott Laboratories.