Comparison of Double-syringe vs Single-syringe Technique of Adenosine Administration for Termination of Regular-narrow Complex Tachycardia: A Randomized, Controlled Trial

Supraventricular tachycardia (SVT) is the most common tachyarrhythmias in young adults, children, and infants. The most common type in adults is the atrioventricular nodal reentrant tachycardia (AVNRT) and the incidence is 35 per 10,000 person-years or 2.29 per 1000 persons.

The treatment approach of SVT is based on hemodynamical stability. The synchronized cardioversion is recommended for hemodynamically unstable patients, on the other hand, the vagal maneuvers and medications are considered for patients with stable hemodynamic.

To date, the 2019 ESC guideline for the management of supraventricular tachycardia stated that adenosine is still the first medication for acute therapy in patients with SVT if the vagal maneuver fails or is contraindicated. A systematic review in 2021 showed that adenosine is equally efficacious for treating SVT, but it is safer than intravenous calcium channel blockers due to a shorter half-life.

Few studies reported that the effectiveness of conventional vagal maneuvers, namely, carotid sinus massage in SVT termination was around 19 to 54% when properly done. The enhanced method of vagal maneuver or named the modified syringe technique was performed by blowing into a 10 mL syringe to move the plunger, the success conversion rate of SVT was a little better than the convention technique (43% vs 17%). Therefore, adenosine is still crucial in the acute therapy of SVT in an emergency setting.

Adenosine has been discovered since 1929 and used in the acute treatment of arrhythmias. It was used as a therapeutic diagnosis in patients with regular narrow QRS complex tachyarrhythmias and it is also helpful in treating some type of regular wide QRS complex tachyarrhythmias (differentiate between SVT with aberrancy/bundle branch block and ventricular tachycardia).