EARLY COMPLICATIONS OF PERMANENT PACEMAKER IMPLANTATION - NO DIFFERENCE BETWEEN DUAL AND SINGLE CHAMBER SYSTEMS

Objective-To evaluate the incidence of intraoperative and early postop erative complications (up to two months after implant) of endocardial permanent pacemaker insertion in all patients under-going a first impl ant at a referral centre. Methods-Prospective evaluation of all endoca rdial pacemaker implantation procedures performed from April 1992 to J anuary 1994 carried out by completion of standard audit form at implan t. Patients' demographic data, medical history, details of pacemaker h ardware used, and any complications were noted. Follow up information was also collected prospectively onto standard forms at pacemaker outp atient clinic. Setting-United Kingdom tertiary referral cardiothoracic centre. Patients-1088 consecutive patients underwent implantation of their first endocardial . permanent pacemaker from April 1992 to Janua ry 1994. Implant and follow up data were available for 1059 (97 . 3%) patients at analysis. The median (range) age was 77 years (16-99); 51 . 2% were male. Results-Dual chamber units were implanted in 54 . 1% o f patients,single chamber atrial in 5 . 2%, and ventricular in 40 . 7% . A temporary pacing lead was present at implant in 22 . 9% of patient s. Most (93 . 6%) implants were performed via the subclavian vein. Imm ediate complications were rare: eight (0 . 8%) patients developed pneu mothorax requiring medical treatment and 11 (1 . 0%) an insignificant pneumothorax. There was no significant difference in the pneumothorax rate for dual chamber (DDD) compared with single chamber systems. Arte rial puncture without sequelae was documented in 2 . 7% of attempts at subclavian vein cannulation. A total of 35 patients (3 . 3%) required reoperation; the reoperation rate for dual chamber (3 . 5%) was simil ar to that for single chamber (3 . 1%) systems. Electrode displacement (n = 15, 1 . 4%) was the most common reason for reoperation. Atrial l ead displacement (n = 10, 1 . 6% of atrial leads) was significantly mo re common than ventricular lead displacement (n = 5, 0 . 5% of ventric ular leads, P = 0 . 047). There was no difference in electrode displac ement rates for dual (1 . 6%) compared with single (1 . 2%) chamber sy stems. Pacemaker pocket infection led to reoperation in 10 patients (s ix dual, four single chamber, P = not significant) and was significant ly more common in patients who had a temporary pacing lead in place at implant (2 . 9%) than in those who did not (0 . 4%, P 0 . 0014). Five patients (0 . 5%) required reoperation for generator erosion (two dua l, three single chamber, P = not significant) and a further five for d rainage of haematoma or a serous fluid collection (three dual, two sin gle chamber, P = not significant). Complications that did not require reoperation were also rare. Undersensing occurred in 10 patients (0 . 9%). Atrial undersensing (n = 8) was significantly more common than ve ntricular undersensing (n = 2, P = 0 . 017). All patients were success fully treated by reprogramming of sensitivity. Superficial wound infec tion was treated successfully with antibiotics in nine patients (six d ual, three single chamber, P = not significant). Three patients with D DD generators developed sustained atrial fibrillation: two required re programming to VVI mode and one required cardio-version. Conclusions-P ermanent pacing in a large tertiary referral centre with experienced o perators carries a low risk. Infection rates are low, < 1% overall but significantly higher in patients who undergo temporary pacing before implantation. Lead displacement and undersensing are more likely to oc cur with atrial than ventricular leads. The overall complication rate for dual chamber pacing, however, is no higher than for single chamber pacing.