Implantable medical device for treating cardiac mechanical dysfunction by electrical stimulation

US6738667B2 · kind B2 · utility

Assignee

• Medtronic, Inc. · US

Inventors

• D. Curtis Deno · Missouri City, US
• Lawrence J. Mulligan · Andover, US
• Tom D. Bennett · Shoreview, US
• David Igel · Lino Lakes, US
• Michael R. S. Hill · Minneapolis, US
• Richard J. Shaw · St. Francis, US

Key dates

• Filing date: Dec 28, 2000
• Grant date: May 18, 2004
• Expiry date: Jul 19, 2022

Classification

• Technology area (CPC A): Human Necessities
• CPC primary: A61N1/36564
• WIPO field: Medical technology
• WIPO sector: Instruments

Abstract

An implantable stimulator and monitor measures a group of heart failure parameters indicative of the state of heart failure employing EGM signals, measures of blood pressure including absolute pressure P, developed pressure (DP=systolic P−diastolic P), and/or dP/dt, and measures of heart chamber volume (V) over one or more cardiac cycles. These parameters include: (1) relaxation or contraction time constant tau (&tgr;); (2) mechanical restitution (MR), i.e., the mechanical response of a heart chamber to premature stimuli applied to the heart chamber; (3) recirculation fraction (RF), i.e., the rate of decay of PESP effects over a series of heart cycles; and (4) end systolic elastance (EES), i.e., the ratios of end systolic blood pressure P to volume V. These heart failure parameters are determined periodically regardless of patient posture and activity level. The physician can determine whether a particular therapy is appropriate, prescribe the therapy for a period of time while again accumulating the stored patient data for a later review and assessment to determine whether the applied therapy is beneficial or not, thereby enabling periodic changes in therapy, if appropriate.…