Scott W Swift

US Patent:

50852159, Feb 4, 1992

Filed:

Mar 20, 1990

Appl. No.:

7/497002

Inventors:

Tibor A. Nappholz - Englewood CO
Scott Swift - Miami FL
John R. Hamilton - Littleton CO
Matthew J. Gani - Littleton CO

Assignee:

Telectronics Pacing Systems, Inc. - Englewood CO

International Classification:

A61N 1368

US Classification:

128419PG

Abstract:

A rate-responsive dual-chamber pacemaker and pacing method for supporting the heart with electrical stimulation at a pacing rate driven by the heart's sinus node or, alternatively, by a sensor adapted to determine the patient's metabolic demand (a metabolic demand indicator). The pacemaker automatically selects between the indicated rates to determine the best pacing rate for appropriately satisfying metabolic demand at all times. The natural rate, driven by the sinus node, takes precedence over the metabolic indicator rate provided the natural rate meets a standard determined by the metabolic demand indicator rate. The pacemaker upper rate response mechanism allows atrioventricular synchrony at natural sinus rates ranging from low rates to high exercise rates, even up to the programmed maximum rate, but maintains ventricular rate stability during pathological atrial tachycardias by reverting to pacing in a rate-responsive VVI mode.