ADENOSINE-TRIPHOSPHATE UTILITY IN SUPRAVENTRICULAR PAROXISMAL TACHYCARDIA

With the objective to evaluate adenosine triphosphate (ATP) usefulness in supraventricular paroxysmal tachycardia (SPT), doses of 0,25 mg/kg, of ATP are administered fastly I.V. in bolus, to fifty consecutive patients with SPT resistant to vagal stimulation maneuvers. The effect achieved allowed to identify two groups: a) 39 patients in whom tachycardia was interrupted; b) 11 patients in whom tachycardia did not cease, but the induced transient provoked atrial-ventricular (A-V) blockage allowed to identify the underlying mechanism of tachycardia (in 6 of them atrial tachycardia and in 5 atrial flutter). In both groups the ATP effect was present in less than 30 seconds. In seven patients (five from group (a) and two from group b) the QRS duration was over 0.12 s. Six patients had a left ventricular ejection fraction below 30%. Side effects were frequent, but always short. ATP could become the drug of choice in the treatment of SPT without response to vagal maneuvers, due to the fact that, to its therapeutic activity, it must be added its diagnostic usefulness, its fast action and metabolization, together with the fact that it does not induce severe side effects.