The adenosine triphosphate test: A bedside diagnostic tool for identifyingthe mechanism of supraventricular tachycardia in patients with palpitations

Objectives This study assesses the value of the "ATP test" (injection of ad enosine triphosphate [ATP] during sinus rhythm) for identifying patients wi th palpitations of unclear etiology who actually have atrioventricular (AV) nodal re-entry tachycardia (AVNRT) or AV re-entry tachycardia (AVRT). Background Because AVNRT and AVRT can be cured with radiofrequency ablation , documentation of spontaneous AVNRT or AVRT usually prompts referral for e lectrophysiologic (EP) evaluation. However, these paroxysmal arrhythmias ma y elude clinical diagnosis. We recently showed that administration of ATP d uring sinus rhythm often reveals dual AV node physiology or a concealed acc essory pathway (AP) in patients with documented AVNRT or AVRT. Thus, we pos tulated that the ATP test could identify patients with Palpitations who act ually have AVNRT or AVRT and would therefore benefit from EP evaluation. Methods One hundred forty-six patients (54 with "palpitations without docum ented arrhythmias" and 92 with "documentation of arrhythmias of unclear mec hanism") underwent a noninvasive ATTP test. ATP was injected during sinus r hythm using 10 mg increments. The ATP test was considered positive when pro spectively defined signs of dual AV node physiology or concealed AP were di sclosed in the electrocardiogram. These findings were correlated with the r esults of EP evaluation. Results A positive ATP test predicted induction of AVNRT or AVRT with a pos itive predictive value of 93% (sensitivity 71%) but a negative predictive v alue of 37% (specificity 76%). Conclusions A bedside ATP test identifies patients with palpitations who ar e likely to have AVNRT or AVRT (and who are therefore likely to benefit fro m EP evaluation) with a high positive predictive value. (J Am Coll Cardiol 2001;38:173-7) (C) 2001 by the American College of Cardiology.