Autocapture pacing/sensing configuration

• US 7,512,441 B2
• Filed: 01/02/2001
• Issued: 03/31/2009
• Est. Priority Date: 12/08/1998
• Status: Expired due to Fees

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Kim, Jungkuk, Zhang, Geng, Zhu, Qingsheng
• Primary Examiner(s): SCHAETZLE, KENNEDY
• Application Number:
  US09/753,738
• Publication Number:
  US 20010031990A1
• Time in Patent Office: 3,010 Days
• Field of Search: 607/28, 607/27, 607/13, 607/9, 600/509
• US Class Current: 607/28
• CPC Class Codes: A61N 1/3712 Auto-capture, i.e. automatic adjustment of the stimulation threshold
• CPC Class Codes: A61N 1/3716 with reduction of residual polarisation effects

Abstract

A cardiac electrical stimulation system that enhances the ability of the system to automatically detect whether an electrical stimulus results in heart capture or contraction. The cardiac electrical stimulation system may be utilized, for example, as a cardiac pacer or as a cardioverter defibrillator. The cardiac electrical stimulation system includes an electrical stimulation circuit that attenuates polarization voltages or “afterpotential” which develop at the heart tissue/electrode interface following the delivery of a stimulus to the heart tissue, which thereby allows the stimulation electrodes to be utilized to sense an evoked response to the electrical stimulus. The cardiac electrical stimulation system utilizes the stimulation electrodes to sense an evoked response, thereby eliminating the necessity for an indifferent electrode to sense an evoked response. The present invention allows accurate detection of an evoked response of the heart, to thereby determine whether each electrical stimulus results in capture.

Claims

1. An electrical cardiac stimulation system having an autocapture/stimulation/sensing configuration for use with atrial and ventricular leads, said electrical cardiac stimulation system including:

(a) a combination of electrodes selected from a plurality of possible combinations of atrial and ventricular electrodes;

(b) a stimulation system enclosed in a housing, said stimulation system being electrically coupled to each said atrial electrode and each said ventricular electrode for providing an electrical pacing stimulus to at least one of an atrium or ventricle of a heart;

(c) a sensing circuit that senses an evoked response by the heart to the electrical stimulus, wherein a signal associated with an evoked response from the electrical stimulus is sensed between at least two of said electrodes of said combination and wherein said sensing circuit is adapted to selectively sense evoked responses between all combinations of any two of said electrodes;

(d) an afterpotential attenuation device for attenuating afterpotentials which result due to the application of the pacing stimulus to the heart by said electrical stimulation system, said afterpotential attenuation device being electrically coupled to said stimulation system; and

,

(e) wherein said afterpotential attenuation device comprises a switch for reducing a coupling capacitance through which the pacing stimulus is delivered.

2. An electrical cardiac stimulation system as in claim 1 wherein the electrical stimulus conducts electrically between an atrial tip electrode and the housing.

3. An electrical cardiac stimulation system as in claim 1 wherein the electrical stimulus conducts electrically between a ventricular tip electrode and the housing.

4. An electrical cardiac stimulation system as in claim 1 further comprising a superior vena cava coil electrode and wherein the signal associated with the evoked response can be selectively sensed between any one of a group of combinations of electrodes consisting of an atrial ring electrode to ventricular ring electrode, atrial ring electrode to can electrode, atrial ring electrode to ventricle coil electrode, atrial ring electrode to superior vena cava coil electrode, atrial tip electrode to ventricular coil electrode, atrial tip electrode to ventricular tip electrode, atrial tip electrode to atrial ring electrode, superior vena cava coil electrode to atrial tip electrode, superior vena cava coil electrode to ventricular coil electrode, superior vena cava coil electrode to ventricular tip electrode, ventricular tip electrode to ventricular coil electrode, superior vena cava coil electrode to ventricular ring electrode, and ventricular ring electrode to ventricular coil electrode.

5. The system of claim 1 wherein the switch for reducing a coupling capacitance through which the pacing stimulus is delivered connects a first coupling capacitor in series with a second coupling capacitor.

6. An electrical cardiac stimulation system having an autocapture stimulation/sensing configuration for use with atrial and ventricular leads, said electrical cardiac stimulation system including:

(a) a combination of electrodes selected from a plurality of possible combinations of atrial and ventricular electrodes;

(b) a stimulation means enclosed in a housing, said stimulation means being electrically coupled to each said atrial electrode and each said ventricular electrode for providing an electrical pacing stimulus to at least one of an atrium or ventricle of a heart;

(c) a sensing means that senses an evoked response by the heart to the electrical stimulus, wherein a signal associated with an evoked response from the electrical stimulus is sensed between at least two of said electrodes of said combination and wherein said sensing means is adapted to selectively sense evoked responses between all combinations of any two of said electrodes;

(d) an afterpotential attenuation means for attenuating afterpotentials which result due to the application of the pacing stimulus to the heart by said electrical stimulation means, said afterpotential attenuation means being electrically coupled to said stimulation means; and

,

(e) wherein said afterpotential attenuation device comprises means for reducing a coupling capacitance through which the pacing stimulus is delivered.

7. An electrical cardiac stimulation system as in claim 6 wherein the signal associated with the evoked response is sensed between an atrial ring electrode and a ventricular electrode.

8. An electrical cardiac stimulation system as in claim 6 wherein the electrical stimulus conducts electrically between an atrial tip electrode and the housing.

9. An electrical cardiac stimulation system as in claim 6 wherein the electrical stimulus conducts electrically between a ventricular tip electrode and the housing.

10. The system of claim 6 wherein the means for reducing a coupling capacitance through which the pacing stimulus is delivered connects a first coupling capacitor in series with a second coupling capacitor.