[The use of pace-makers with programmable frequency in the control of hyperkinetic ventricular "refractory"...

The electrophysiological basis of the treatment of hyperkinetic "refractory" arrhythmias with rate - programmable pacemakers, stems from the pacing-inducted electrophysiological modifications with higher and time programmable threshold rates being obtainable to suppress the arrhythmias. Furthermore antiarrhythmic agents, that must be generally associated, are more safely employed. This is a new application in clinical arrhythmology of a particular type of permanent pacemaker whose classic indications are well known. The Authors report their experience relative to 16 selected patients affected by severe cardiopathies. Three types of pacemakers were employed: Omnis Stanicor Cordis; Microlith C.P.I.; and Byrel A-V Sequential, Medtronic. The results, in term of the suppression of the arrhythmias, were encouraging. The most striking problem is to match the "rate threshold" for the suppression of the arrhythmia with the patient's hemodynamic tolerance: not infrequently in fact the programmed rates are poorly tolerated by the patient either because of heart failure or due to coronary insufficiency. These patients need frequent adjustment of the stimulation rate. The availability of rate programmable pacemakers with steps of one beat per minute, of A-V sequential stimulation and, when feasible of atrial stimulation, undoubtedly plays an important role in clinical arrhythmology.