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 w ith a ventricular electrode at the tip and at least one atrial ring el ectrode. The disadvantage of VDD systems is that the full range of DDD stimulation and defection alternatives is not available. The present animal study was made to evaluate a new single lead design with the di stal electrode placed in the atrium and the proximal ring electrode in the right ventricle. This design permits the full range of DDD option s including atrial stimulation. Acute stimulation thresholds and sensi ng amplitudes were stable and comparable to conventional DDD systems. Long-term studies are on-going.