Sustained effectiveness of an atrial antitachycardia pacemaker during follow-up

Atrial antitachycardia pacemakers are indicated for medically refractory atrial tachyarrhythmias. To confirm long-term device effectiveness, we studied diagnostic data obtained in 17 patients with atrially-placed Intermedic "Intertach" pacemakers. The unit has programmable primary (P mod) and secondary (S mod) antitachycardia response protocols. Success of the P mod was defined as a P mod response first with no subsequent S mod response. Follow-up was for 595 days (+/- 302 days). The P mod was utilized first 88.2 +/- 102 times per patient interrogation with subsequent S mod use 21.1 +/- 53 times (P less than 0.0001). Results were also significant when P mod was compared to S mod in the first versus the last half of follow-up (both P less than 0.0001). These results suggest that the programmed P mod of the atrial "Intertach" tachycardia reversion pacemaker has sustained effectiveness in the treatment of medically refractory atrial tachyarrhythmias.