Battery conservation in implantable cardioverter-defibrillators and pacemakers

• US 6,363,280 B1
• Filed: 10/15/1999
• Issued: 03/26/2002
• Est. Priority Date: 10/15/1999
• Status: Expired due to Fees

• Current Assignee: Pacesetter Incorporated (Abbott Laboratories)
• Original Assignee: Pacesetter Incorporated (Abbott Laboratories)
• Inventors: Causey, James D. III, Mouchawar, Gabriel
• Primary Examiner(s): Evanisko, George R.
• Assistant Examiner(s): BIRD, JOHN M
• Application Number:
  US09/418,925
• Time in Patent Office: 893 Days
• Field of Search: 607/4, 607/5, 607/9, 607/14, 607/16
• US Class Current: 607/16
• CPC Class Codes: A61N 1/378 Electrical supply
• CPC Class Codes: A61N 1/3956 Implantable devices for applying electric shocks to the heart, e.g. for cardioversion

Abstract

In an implantable cardioverter-defibrillator and/or pacemaker, each having DDD pacing capabilities, an improved method of operation is described which dramatically increases the longevity of the implanted device by conserving battery power. The method comprises deactivating at least one unnecessary, power-consuming feature of the device until such feature is needed and then reactivating said feature only for so long as it is required by the patient. In a particular embodiment, the atrial sense amplifier is deactivated during normal operation of the implantable device, resulting in single-chamber sensing and pacing. Upon the occurrence of a predefined event, indicative of a need for dual-chamber sensing and pacing, the atrial sense amplifier is reactivated, the need for DDD pacing confirmed, and if appropriate, DDD pacing is begun. Once the patient'"'"'s heart rate has returned to an acceptable level, the atrial sense amplifier is again deactivated and single-chamber sensing/pacing continued. In addition, the atrial sense amplifier of an ICD/pacemaker is deactivated during normal operation of the device and reactivated immediately following the detection of ventricular tachycardia. In this embodiment, DDD sensing/pacing is preferably automatically begun following this detection. Also contemplated herein, are improved devices employing the improved methods.

Claims

1. In an implantable ICD/pacemaker, having DDD pacing capabilities and having an atrial sense amplifier, a ventricular sense amplifier, a ventricular pulse generator, an atrial pulse generator, a control/timing circuit, an activation/deactivation circuit for activating and deactivating the atrial sense amplifier, cardioversion-defibrillation circuitry, and a memory circuit, wherein the atrial sense amplifier is initially in a deactivated state, a method of operation for reducing power consumption of the ICD/pacemaker comprising the steps of:

sensing an arrhythmia with the ventricular sense amplifier;

providing therapy to correct the arrhythmia, wherein the therapy is selected from the group consisting of ventricular pacing, cardioversion and defibrillation;

activating the atrial sense amplifier in response to a predefined event, wherein the predefined event is selected from the group consisting of detecting a ventricular pacing rate greater than a predetermined amount, detecting a sequential number of ventricular paces greater than a predetermined number, and detection of ventricular arrhythmia;

sensing heart activity with the atrial sense amplifier and ventricular sense amplifier; and

deactivating the atrial sense amplifier when the heart activity is within predefined acceptable limits, thereby reducing the power consumption of the implantable ICD/pacemaker.

2. The method of claim 1, further comprising initiating DDD pacing and sensing following activation of the atrial sense amplifier in response to a predefined event selected from the group consisting of detection of ventricular arrhythmia or tachycardia.

3. The method of claim 1, further comprising confirming the need for DDD pacing after activating the atrial sense amplifier and initiating atrial sensing.

4. The method of claim 3, further comprising recording in the memory circuit the frequency and type of therapy provided including recording sequential ventricular pacing events and frequency of ventricular pacing events that exceed predetermined limits.