[Use of implantable pacemaker in the treatment of paroxysmal supraventricular tachycardia refractory to pharmacologic therapy]. / Uso de marcapasso implantável no tratamento da taquicardia supraventricular paroxística refratária à terapêutica farmacológica.

ABSTRACT

PURPOSE: To evaluate the results with the use of an automatic antitachycardia pacemaker in patients with refractory paroxysmal supraventricular tachycardia. PATIENTS AND METHODS: Nine patients aged 32 to 63 years with symptoms from 2 to more than 40 years and prophylactic treatment with several antiarrhythmic drugs that had failed to control tachycardia. The frequency of attacks in the year before the implant was from 1 per month to 3 daily and 4 of patients required direct counter current cardioversion at least once. The electrophysiologic studies demonstrated atrioventricular (AV) nodal reentry in 6 and AV reentry utilizing an accessory AV connection in 4 patients (in one patient both mechanisms were present). The patients have been followed from 2 to 18 months. RESULTS: All patients experienced new episodes of the arrhythmia that were successfully terminated by the pacemaker. Two patients presented episodes of tachycardia not terminated by the pacemaker. These events were successfully treated by reprogramming the unit. The drug treatment was discontinued in 7 patients. CONCLUSION: The antitachycardia pacemaker proved to be an effective therapeutic tool in reentrant supraventricular tachycardia refractory to pharmacologic therapy.