[Electrophysiological effects of different dosage of adenosine triphosphate on normal sinoatrial and atrioventricular node].

In order to study the electrophysiological basis of smaller dosage that would terminate PSVT effectively and decrease side effects remarkably, we have observed the electrophysiological effects of ATP in different dosage (5mg, 10mg, 15mg) on the sino-atrial node (SAN) and atrioventricular node (AVN). Cardiac electrophysiological investigations were carried out in 62 patients with history of PSVT by using the method of trans-esophagus ECG and body surface ECG continuously and simultaneously, during the normal sinus rhythm and PSVT. The results showed that when the effect of 10mg ATP on SAN was not clinically significant yet, it did strikingly block the AVN conduction enough to terminate the PSVT with no severe arrhythmias. 37 cases of 62 patients were provoked PSVT during control electrophysiological study, the PSVTs of 33 cases out of these 37 patients (89.7%) were terminated by using 10mg ATP. There was no serious bradyarrhythmias after PSVT termination. We suggest that 10mg ATP is a reliable dose for PSVT termination.