Use of Holter functions of the implantable pacemaker to control antiarrhythmic therapy of supraventricular and ventricular recurrent tachycardias.

Holter functions of pacemakers were studied in a total of nine patients with paroxysmal atrial flutter (Group I--a Quintech DD 931 pacemaker, manufactured by Vitatron Medical, The Netherlands), and in 11 patients with recurrent postinfarction ventricular tachycardia (Group II--a DPG P 21 diagnostic pulse generator, Vitatron Medical. Seven patients (35%) were excluded from the study for myopotential interference. Group I patients were given six antiarrhythmic drugs for eight weeks each, with only prajmalin and amiodarone significantly shortening flutter duration. Group II patients were administered, according to the results of programmed extrastimulation, amiodarone alone or in combination with Class I antiarrhythmic drugs for a long period of time. While no recurrent tachycardias or sudden death were noted during treatment, pacemaker detected non-lethal ventricular tachycardia occurred in two, and sudden death without confirmed arrhythmia in one patient once the treatment had been discontinued for serious side effects (p less than 0.05). Diagnostic stimulation using bipelar sensing to eliminate myopotential interference might become a major method for long-term monitoring.