Electrical cardiac output forcing method and apparatus for an atrial defibrillator

• US 5,735,876 A
• Filed: 10/25/1995
• Issued: 04/07/1998
• Est. Priority Date: 05/31/1994
• Status: Expired due to Term

• Current Assignee: Galvani, Ltd.
• Original Assignee: Galvani, Ltd.
• Inventors: Kroll, Mark W., Kroll, Kai
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US08/548,014
• Time in Patent Office: 895 Days
• Field of Search: 607/4, 607/5, 607/7
• US Class Current: 607/5
• CPC Class Codes: A61N 1/3622 comprising two or more electrodes co-operating with different heart regions
• CPC Class Codes: A61N 1/3625 External stimulators
• CPC Class Codes: A61N 1/3918 characterised by shock pathway, e.g. by electrode configuration
• CPC Class Codes: A61N 1/395 for treating atrial fibrillation

Abstract

An implantable device for temporarily maintaining cardiac output through the use of electrical forcing fields in the event of an atrial defibrillation shock causing ventricular fibrillation. The device includes an atrial defibrillator. In the event that an atrial defibrillation shock causes a ventricular fibrillation the apparatus and method then delivers a continuous train of modest voltage pulses to force partial cardiac contractions to maintain life and consciousness until the patient can receive external defibrillation.

Claims

1. An implantable device for inducing electrical cardiac output in cooperation with an atrial defibrillation therapy system wherein the electrical cardiac output is triggered in the event of atrial defibrillation therapy causes ventricular fibrillation, the device including the atrial defibrillation therapy system comprising:

a power supply system;

a high voltage pulse generating circuit being in electrical communication with said power supply;

at least one electrode adapted for placement in a patient'"'"'s atrium having electrical connections to said high voltage pulse generating circuit;

control means connected to the high voltage pulse generating circuit to deliver a voltage pulse via said at least one electrode when the atrial fibrillation is detected;

said power supply system, said high voltage, said electrode and said control means being in electrical communication and structured to form said atrial defibrillation therapy system;

a charging circuit connected to said power supply capable of generating voltage pulses of 30-375 volts at a rate of least one pulse per second;

a capacitor for storing energy from said charging circuit;

at least one large electrode adapted to be placed in a patient'"'"'s ventricle;

an output circuit having electrical communication with a capacitor for delivering voltage pulses to said at least one large electrode wherein said voltage pulses are administered upon sensing ventricular fibrillation; and

said charging circuit, said capacitor, said large electrode and said output circuit being in electrical communication and structure to form said implantable device and further having electrical communication and cooperation with said atrial defibrillation therapy system.

2. The apparatus of claim 1 wherein said large electrode includes dimensional parts which vary from a smaller section to a bigger section, the bigger section being greater than one centimeter.

3. The device of claim 1 in which said generated voltage pulses of 30-375 V include at least one gradual edge profile such that said voltage pulses rising from 30 to 375 volts require at least 100 microseconds.

4. The device of claim 1 in which each of said generated voltage pulses further includes at least six narrow pulses in parallel formation.

5. The device of claim 1 wherein said at least one electrode is same as said large electrode.

6. The device of claim 1 wherein said at least one electrode adapted to be placed in the atrium is structured to cooperate with said large electrode to provide a current path to thereby trigger the electrical cardiac output.

7. The device of claim 6 wherein the electrical cardiac output width is shorter than said voltage pulse applied to said at least one electrode adapted for placement in the atrium to direct said voltage pulse into the atrium and further said electrical cardiac output being sequenced to be deliverable prior to the voltage pulse being directed into the atrium.

8. A method of electrically controlling an atrial fibrillation in a patient wherein an atrial defibrillation therapy system results in ventricular fibrillation and an implantable device in cooperation with the atrial defibrillation therapy system supplies an electrical cardiac output upon sensing the onset of the ventricular fibrillation, comprising the device-implemented steps of:

providing a plurality of electrodes adaptable to be placed at one of proximate and inside a patient'"'"'heart;

detecting presence of atrial fibrillation in said patient'"'"'s heart;

delivering an electrical shock to said patient'"'"'s heart upon detection of an onset of said atrial fibrillation;

monitoring for possible ventricular fibrillation; and

delivering a series of electrical pulses to said patient'"'"'s heart at a rate between 60 and 200 pulses per minute and at a voltage of between 30 and 375 volts to induce contraction in the patient'"'"'s ventricle and to enable a minimum cardiac electrical output sufficient to maintain life.

9. The method of claim 8 wherein each of said series electrical pulses includes a formation structure having a gradual rise times greater than 100 microseconds such that said pulses are adaptable for use in human patients wherein said gradual rise minimizes patient discomfort and chest twitching.

10. The method of claim 8 further comprising the step of forming each of said series of electrical pulses of a discreet train of at least 10 narrow pulses to minimize patient discomfort and chest twitching.

11. The method of claim 8 further comprising the step of delivering a current above 300 milliamperes to induce said electrical cardiac output.

12. The method of claim 8 further comprising the step of storing atrial fibrillation sensing events in a microprocessor memory.

13. The method of claim 8 further comprising the step of storing ventricular fibrillation sensing events in a microprocessor memory.

14. The method of claim 8 in which one of said plurality of electrodes is adapted to be placed in the atrium of the patient'"'"'s heart and further that said electrode is implemented to deliver said electrical pulses to the heart to induce contraction in the patient'"'"'s heart.

15. An implantable device including an atrial defibrillation system and a ventricular fibrillation control system wherein resultant ventricular fibrillation is caused by the atrial defibrillation system during a treatment of a heart patient, the implantable device comprising:

a power supply system;

means for detecting fibrillation having electrical connection to said power supply system;

means for integrating said power supply system and said means for detecting fibrillation to be adaptable for placement in the patient'"'"'s heart; and

means for controlling electrical output connected to said means for detecting, said power supply system and said means for integrating to deliver a series of electrical pulses to the heart upon detection of a ventricular fibrillation wherein said series of electrical pulses include a voltage between 30 and 375 volts to force a minimum level of cardiac output sufficient to maintain life.

16. The device of claim 15 further comprising means for pacing the heart for bradycardia wherein a slow heart beat is paced back to within a normal beat per minute range.

17. The device of claim 15 in which said means for controlling electrical output includes a high energy and further includes an inverter powered by said power supply system.

18. The device of claim 15 wherein said means for controlling includes a voltage multiplier powered by said power supply system.

19. The device of claim 15 further comprising means for storing data including programmable parameters and the patient'"'"'s detected internal electrical signals wherein said means for storing is implemented in a microprocessor to store and process the data.

20. The device of claim 15 further comprising means for communicating with a device external to the patient'"'"'s body such that a communication and data exchange structure is implemented between said implantable device and said external device.

21. The device of claim 15 further comprising means for indicating operational status of said power supply system.