[Incessant supraventricular tachycardia. Retrospective study of 13 patients]

To evaluate, retrospectively, the main clinical findings observed in patients with incessant supraventricular tachycardias.

Data from 13 patients were analyzed, 8 men and 5 women, mean age 24 +/- 19 years. All patients underwent to periodic clinical evaluation with serial ECG, Holter, echocardiography and in three patients an electrophysiological study. From these diagnostic methods it was possible to define the site of origin of the tachycardias, the autonomic influences upon them, the progressive hemodynamic compromise leading to tachycardiomyopathy and the drug response.

In 9 patients the tachycardias had an atrial origin, in three an accessory pathway was involved and in one patient an atypical nodal reentry was identified. Clear autonomic influences upon the rate of the tachycardias were noted in the majority of patients, based on Holter recordings. Forty-six percent of the population developed progressive contractile deficit, contributing in one patient to his death. Drug failure was observed in 62% of patients, even with the use of three antiarrhythmic drugs in a row. The large majority of the patients were still asymptomatic by the time of the retrospective data.

The most relevant clinical aspects are the progressive development of tachycardiomyopathy, associated with refractoriness to drug therapy and indicate in this population the approach to be undertaken.