A new dual chamber single lead system

A DDD pacing system normally requires the introduction and positioning of two separate electrode leads. A VDD system may use a single lead with a ventricular electrode at the tip and at least one atrial ring electrode. The disadvantage of VDD systems is that the full range of DDD stimulation and detection alternatives is not available. The present animal study was made to evaluate a new single lead design with the distal electrode placed in the atrium and the proximal ring electrode in the right ventricle. This design permits the full range of DDD options including atrial stimulation. Acute stimulation thresholds and sensing amplitudes were stable and comparable to conventional DDD systems. Long-term studies are on-going.