New Automatic Rate-Adaptive
Pacemaker System

FDA has approved a pacemaker system using a new method of motion detection that automatically paces the heart in proportion to the patient's exercise intensity.

The VIGOR DR Model 1230/1235 (dual chamber) and the SR Model 1130/1135 (single chamber) rate-responsive pacemaker systems use an integrated circuit accelerometer to measure changes in a patient's physical activity and adjust the heart rhythm accordingly.

This technology differs from other marketed adaptive-rate, activity-based pacemakers. Existing rate-modulated, activity-based pacemakers use piezoelectric sensors that are susceptible to environmental influences unrelated to physical activity, such as vibration when riding in a car or static pressure while a patient sleeps on his or her chest. The VIGOR's accelerometer is integrated in the electronic circuit, which allows the device to be more specific, sensitive, and proportional to body motion.

In addition to the generally accepted indications for dual-chamber and single-chamber long-term pacing, the adaptive-rate pacing modes of the device are indicated for patients exhibiting chronotropic incompetence and those who would benefit from increased pacing rates that correspond with physical activity.

VIGOR DR is the first physical activity sensor to receive FDA approved indications for dual-chamber, adaptive-rate pacing therapy. The decision to approve the VIGOR DR/SR systems was based on a review of safety and effectiveness data submitted by the manufacturer, Cardiac Pacemakers, Inc., of St. Paul, Minnesota. The data were derived from two clinical studies that involved a total of 157 patients and began in 1993. Results demonstrated that a well-designed clinical study (randomized, with concurrent controls, clear objectives, hypotheses, endpoints, and appropriate statistical analyses) can support approval and proper labeling of these types of medical devices with a relatively small number of study patients.