Delayed adenosine therapy is associated with the refractory supraventricular tachycardia in children

To study the association of time intervals on adenosine therapy with the occurrence of refractory supraventricular tachycardia (SVT) in children.We reviewed 334 episodes of presumed SVT requiring adenosine in children (18 years) who visited 4 academic hospital emergency departments (EDs) from July 2013 through June 2017. Refractory SVT was defined as an SVT episode persisting after 2 doses of adenosine. Clinical and electrocardiographic findings, and symptom-to-adenosine (symptom-to-ED plus ED-to-adenosine) time of refractory and responsive SVT episodes were compared. Multivariable logistic regression was performed to identify factors associated with the occurrence of refractory SVT.Of 211 SVT episodes, 42 episodes of refractory SVT (19.9%) were noted (overall sinus conversion rate, 79.6%). The refractory episodes were associated with a higher frequency of known structural heart diseases (9.5% vs. 1.8%; P = 0.030) and a longer median ED-to-adenosine time (15.5 vs. 11.0 min; P = 0.018). The association of the ED-to-adenosine time with refractory SVT remained significant after adjustment (for increment of 1 min; aOR, 1.02; 95% CI, 1.007-1.04).Delayed adenosine therapy is associated with the occurrence of refractory SVT in children, supporting the need for prompt adenosine therapy.