ATP is an endogenous nucleotide that has potential electrophysiologic effects. The effects of ATP are largely mediated by its metabolite, adenosine, which acts on A1 receptor in myocardium and mediates negative chronotropic, dromotropic, and inotropic action. The purpose of this study is to determine the efficacy and side effects of ATP in the treatment of paroxymal supraventricular tachycardia(PSVT).

We analyzed 28 episodes of PSVT in 22 patients(7 men and 15 women, mean age 467.±15.9 years), who were selected from Jan. 1992 to Sep. 1992. After measuring blood pressure and obtaining a standard 12 leads electrocardiogram(ECG), we rapidly injected ATP intravenously with dose of 10, 15, 20mg every 1 min, until the termination of PSVT.

We recorded peri-injection and post-injection ECG, interval between ATP injection and the termination of PSVT, the pause after termination, side effects and blood pressure immediately after termination.

1) Among 28 episodes of PSVE, 26 episodes(92.9%) were terminated successfully : 21 episodes(75%) with 10mg, 3 episodes(10.7%) with 15mg, and 2 episodes(7.2%) with 20mg of ATP. 2 episodes(7.1%) were failed.

2) The PSVT ended 21.2±9.2 seconds after injection of ATP(maximally 40 seconds).

3) The mechanisms of PSVT in 9 patients were atrioventricular nodal reentrant tachycardia(AVNRT), those in 13 patients were atrioventricular reciprocating tachycardia(AVRT).

4) The side effects of ATP included 13 episodes of chest pain(46.6%), 9 episodes of ventricular arrhythmia(32.1%), 6 episodes of sinus pause(21.4%) and 5 episodes of atrioventricular block(17.9%), and these were uncomplicated and short-lasting.

The ARP is a safe and effective therapy for the conversion of PSVT to sinus rhythm and perhaps more importantly, a valuable new approach to the management and diagnosis of wide-complex tachycardia.