Treatment of drug resistant A-V reciprocating tachycardias with multiprogrammable dual demand A-V sequential (DVI,MN)...

Programmable dual A-V sequential demand (DVI,MN) pacemakers were implanted in eight patients with recurrent or incessant, drug-refractory, A-V reciprocating tachycardias. This was done after intracardiac studies had identified a variety of electrogenetic mechanisms which include tachycardias involving Kent bundles, (manifest or concealed Wolff-Parkinson-White syndrome), nodoventricular (Mahaim) fibers, enhanced A-V node pathways (Lown-Ganong-Levine syndrome), and dual intranodal pathways. The antitachycardia features of the pacemaker were evaluated during the electrophysiological studies. No immediate postoperative complications occurred after implantation. Furthermore, during the follow-up periods (4 to 20 months), clinical assessment, ambulatory (Holter) monitoring and invasive (as well as noninvasive) evaluations have confirmed continuous effectiveness in recognizing and automatically terminating the tachycardias. Late pacemaker system malfunction has not occurred. The frequency of the tachycardias and the dosage of concomitantly-administered antiarrhythmic medications were significantly reduced. Furthermore, preliminary studies performed in our laboratory suggest that DVI,MN pacemakers may also be useful in certain types of intra-atrial reentry tachycardias coexisting with sinus node dysfunction.