Comparative three-year performance of chronic atrial sensing among eight different VDD systems.

In summary, decisions regarding VDD pacing should be individualized by weighing the strengths of a simplified and safe implant technique with the major drawback of notable atrial sensing failure rates over a long-term period. Despite overall unpredictable loss of AV synchrony, efforts to improve chronic reliability of atrial sensing, particularly in patients >60 years, should aim at a high right atrium dipole position, a large and stable intraoperative P-wave amplitude, and a maximum programmable atrial sensitivity of ≤0.1 mV.