CP40: AAISAFER2 PACING MODE: FIRST CLINICAL RESULTS

A new pacing mode was designed to combine the advantages of AAI mode with the safety of DDD for sick sinus syndrome patients (pts.). The objectives of this study were to assess the safety and efficacy of this new mode. Methods The AAIsafeR 2 mode behaves like an AAI mode (no atrio-ventricular (AV) delay) until one of different predefined patterns of AV block or ventricular pause occurs and triggers a switch to DDD. While functioning in DDD, the device periodically intends to switch back to AAI, if spontaneous AV conduction recovery (non-sustained switch: NSS). Too frequent switches to DDD trigger the resumption of AAI up to a daily attempt of AAI switch-back (longlasting switch: LLS) This new pacing mode has been evaluated in 46 pts. (30 males, 74±10 years) implanted with a Symphony DR 2550 pacemaker (ELA Medical, France). Indications were sinus node dysfunction (46%), paroxysmal AV block (35%), both (16%) and Long-QT (2%). Pacemaker statistics were retrieved after one month in 38/46 patients. Pts. were categorized accordingly in no switches (nS), non-sustained and long-lasting switches. Results No adverse event or symptom related to the new pacing mode was reported. All conductions disorders led to an immediate safe V pacing. At 1-month, 28/38 pts. presented commutations (nS : 24%, NSS: 55%, LLS: 21%): View this table: At 1-month, the criteria for switching to DDD were: “AVB III” (n=2), “AVB II” (n=2), various AVB patterns (n=13), ventricular pause (n=1), ventricular pause and various AVB patterns (n=11). Conclusions AAIsafeR 2 preserves ventricular activity in case of paroxysmal AV block while maintaining ventricular pacing below 0.1% in 30/38 (79%) of patients of non-selected DDD patients.