Reliability of Atrial Screw‐in Leads

The aim of this study was to investigate long‐term performance of a carbon coated atrial screw‐in lead. During implantation of 247 leads of this type we measured an average stimulation threshold of 0.74 V(range: 0.2–1.6 V) at 1 ms pulse width. Mean lead impedance came to 446 ohms (range: 263–1000 ohms) resulting in an arithmetical energy consumption of 1.51 μJ(range: 0.1–7.21 μJ). Average P wave amplitude was 3.9 mV (range: 1.3–11 mV). After a mean follow‐up of 16.4 months (range; 3–60 months) we found excellent threshold results in 76% of the patients permitting a safety programming al half of nominal value. An additional 14% nominal settings could be retained. With regard to chronic lead impedance of 488 ohms (range: 315–1327 ohms) we calculated an average chronic energy consumption of 10.83 μJ (range: 1.62–22.78 μJ) during safety programming. This made up 34.6% of the corresponding energy consumption during nominal programming. Eighty percent of the patients showed chronic P waves above 2 mV; nearly half of them (n ‐ 94 = 38%) showed a proper sensing function even when programmed to minimal sensitivity settings or above 4 mV. In 19 leads (8%) we observed unsatisfying threshold results requiring high output programmings. All threshold increases occurred within the first year, 84% (n = 16/19) within the first 3 postoperative months. An additional five leads (2%) were found to have a loss of capture, and one (0.5%) a loss of sensing. These complications required reoperation as well as one dislocation (0.5%) resulting in a low complication rate of 3% as compared to the total complication rate of all implanted atrial leads which was substantially higher (n = 48/652 = 7.5%). With regard to our results we consider the carbon coated atrial screw‐in lead to have proven long‐term reliability.