ABSTRACT
In order to study the mechanism of action of AMP on the AV node conduction, 10 patients with re-entrant tachycardia including the AV node in the circuit (SVT) were studied. The mean age was 32.8 +/- 11.1. Tachycardia was induced by programmed atrial stimulation. Electrophysiological studies were made in all the cases. Intravenous injection of AMP suppressed SVT in all the patients in the first part of the study. The mean doses was 0.095 +/- 0.037 mg/Kg., and the mean time was 15.2 +/- 2.6 sec. In the second part (after 0.04 mg/Kg. IV atropine) the induced SVT was suppressed with a mean doses of 0.122 +/- 0.45 mg/Kg of AMP (P = NSD) in a mean time of 16.2 +/- 2.2 sec. (p = NSD). In the last part of this study the intravenous injection of aminophylline (4 mg/Kg) avoided the suppression of induced SV T in 8/10 patients. In to patients the AMP doses was 0.250 mg/Kg., and in the other 0.075 mg/Kg. Our studies demonstrated that the mechanism of action of AMP is by means of agonistic stimulation of purinergic receptors in the AV node.