DDD pacemakers maximize hemodynamic benefits and minimize complications for most patients.

A 44-month retrospective analysis was performed on 666 pacemakers implanted at Mt. Sinai Medical Center. Mapping techniques and endocardial waveform analyses were used during lead positioning to ensure the best electrical environment. The optimal pacing lead type was selected based on the clinical situation. Follow-up evaluations were rigorous. Patient population ranged in age from 28 to 103 with a mean of 78 years at time of implant. Seventy percent of the patients received DDD pacemakers with an 81% survival incidence at 44 months. Of the VVI population (30% of the implants), there was a 62% survival incidence. Most problems associated with the pacing systems were related to the atrial channel. Loss of atrial sensing occurred in 7.5% of the population and was corrected noninvasively in 5.8%. Due to chronic loss of atrial sensing, 1.7% of the population remained programmed to DVI/VVI. A total of 7.7% were chronically reprogrammed from DDD to VVI, 5.6% secondary to atrial fibrillation. Reoperations were necessary in 1.2% of the malfunctioning systems that could not be corrected by reprogramming. The following conclusions were reached: (1) maximizing hemodynamic benefits and minimizing pacemaker complications permitted a survival rate equal to or better than that of the general population, and (2) chronic problems related to the atrial lead and malfunctions of the pacing system were minimized by careful patient selection, appropriate pacemaker and lead selection, endocardial waveform analysis, and thorough follow-up.

Pacemaker clinic evaluations: key to early identification of surgical problems.

The pacemaker center evaluation was responsible for the timely reoperation of 341 pacemaker patients over the last three years. The most common indication for reoperation was battery end-of-service (46.3%). Battery testing and maintenance of accurate records for trend analysis ensures prompt generator replacement. Atrial and/or ventricular lead malfunction was the second largest indication (26.3%). Lead malfunction detected by bracketing capture and sensing thresholds included: dislodgement, penetration, exit block, fracture, insulation failure, and abnormal sensing. The third largest indication for reoperation was pacemaker pocket erosion and/or infection (15.5%). Examination of the pacemaker pocket site is an integral part of an evaluation. In conclusion, the three largest indications for reoperations can be best demonstrated in a pacemaker center where evaluations are personal and thorough, and accurate record keeping is maintained.