Atrial defibrillator, lead systems, and method

• US 5,433,729 A
• Filed: 03/24/1992
• Issued: 07/18/1995
• Est. Priority Date: 04/12/1991
• Status: Expired due to Term

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: InControl, Inc. (Daikin Industries Ltd)
• Inventors: Krevenhagen, Paul E., Alferness, Clifton A., Adams, John M.
• Primary Examiner(s): Kamm, William E.
• Assistant Examiner(s): Schaetzle, Kennedy J.
• Application Number:
  US07/856,514
• Time in Patent Office: 1,211 Days
• Field of Search: 128/419 D, 607/5, 607/4, 607/122, 607/123
• US Class Current: 607/5
• CPC Class Codes: A61N 1/056 Transvascular endocardial electrode systems
• CPC Class Codes: A61N 1/0563 specially adapted for defibrillation or cardioversion
• 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
• CPC Class Codes: A61N 1/3956 Implantable devices for applying electric shocks to the heart, e.g. for cardioversion
• CPC Class Codes: A61N 1/39622 Pacing therapy
• CPC Class Codes: A61N 1/3987 characterised by the timing or triggering of the shock
• CPC Class Codes: A61N 2001/0585 Coronary sinus electrodes

Abstract

An implantable atrial defibrillator provides a pulse of defibrillating electrical energy to the atria of the heart in synchronism with sensed R waves in response to non-coincident sensing of an R wave at first and second areas of the heart. The defibrillating pulse is provided after a predetermined number of consecutive R waves are non-coincidently sensed to assure reliable synchronization. The atrial defibrillator is also operational in a marker mode wherein a number of synchronization marker pulses are delivered to the heart for detection on an externally generated electrocardiogram. The atrial fibrillation detector of the defibrillator is normally disabled and is activated when the sensed ventricular activity indicates a probability of atrial fibrillation to conserve a depletable power source. A plurality of lead systems are also described for use with the atrial defibrillator which reduce the quantity of electrical energy required to defibrillate the heart and ensure that the delivered atrial defibrillating electrical energy is substantially confined to the atria of the heart.

Claims

1. An implantable device for monitoring activity of the heart and delivering cardioverting electrical energy to the atria of the heart, said device comprising:

storage means for storing said electrical energy;

a first lead including a first electrode, said first lead for disposing said first electrode within the right atrium of the heart;

a second lead including a second electrode, said second lead for disposing said second electrode within the coronary sinus beneath the left atrium of the heart; and

atrial activity sensing means coupled to said first and second electrodes through said first and second leads respectively for sensing atrial activity of the heart,

said storage means being coupled to said first and second electrodes through said first and second leads respectively for applying said electrical energy between said first and second electrodes for delivering said electrical energy to the atria of the heart, and

said first and second leads being fully implantable beneath the skin of a patient.

2. An implantable device as defined in claim 1 wherein said first lead is further arranged for disposing said first electrode in the right atrial appendage of the heart.

3. An implantable device as defined in claim 1 wherein said implantable device further includes electrical activation sensing means for sensing electrical activations of the heart and wherein said lead means includes a third lead having first and second spaced apart sensing electrodes coupled to said electrical activation sensing means and being disposed within the right ventricle of the heart.

4. An implantable device as defined in claim 1 wherein said device further includes electrical activation sensing means and wherein said lead system further includes a third lead having first and second spaced apart sensing electrodes, said electrical activation sensing means being coupled to said first and second sensing electrodes through said third lead for sensing electrical activations of the heart.

5. An implantable device as defined in claim 4 wherein said third lead is arranged for disposing said first and second sensing electrodes within the right ventricle of the heart.

6. An implantable device as defined in claim 5 wherein said first lead is further arranged for disposing said first electrode in the right atrial appendage of the heart.

7. An implantable device for monitoring activity of the heart and delivering cardioverting electrical energy to the atria of the heart, said device comprising:

storage means for storing said electrical energy; and

lead means coupled to said storage means for receiving said electrical energy from said storage means and applying said electrical energy between the right atrium of the heart and the coronary sinus beneath the left atrium of the heart for delivering said electrical energy to the atria of the heart;

wherein said lead means includes a first lead including a first electrode arranged to be disposed within the right atrium of the heart and a second lead including a second electrode arranged to be disposed within the coronary sinus beneath the left atrium of the heart for delivering said electrical energy to the atria of the heart,

wherein said device further includes atrial activity sensing means for sensing atrial activity of the heart, and wherein said atrial activity sensing means is coupled to said first and second electrodes,

wherein said device further includes electrical activation sensing means for sensing electrical activations of the heart and wherein said lead means includes a third lead and first, second, and third spaced apart sensing electrodes carried on said third lead and coupled to said electrical activation sensing means, and

said lead means being fully implantable beneath the skin of a patient.

8. An implantable device as defined in claim 7 wherein said first, second, and third spaced apart sensing electrodes are arranged on said third lead for being disposed within the right ventricle of the heart.

9. An implantable device as defined in claim 8 wherein said first electrode is further arranged for being disposed in the right atrial appendage of the heart.

10. An implantable device as defined in claim 9 wherein said second lead includes a preshaped bend in the region of said second lead within the coronary sinus for fixing said second lead within the coronary sinus.

11. A method of monitoring activity of the heart of a patient and delivering cardioverting electrical energy to the atria of the heart of the patient, said method comprising the steps of:

providing storage means for storing electrical energy;

implanting said storage means beneath the skin of the patient;

providing lead means, including a first lead having a first electrode and a second lead having a second electrode;

implanting said lead means beneath the skin of the patient including the steps of disposing said first electrode within the right atrium of the heart and disposing said second electrode within the coronary sinus beneath the left atrium of the heart;

coupling said lead means to said storage means;

sensing atrial activity of the heart between said first and second electrodes;

storing said electrical energy in said storage means, and

applying, through said lead means, at least a portion of said stored electrical energy between said first and second electrodes to deliver said cardioverting electrical energy to the atria of the heart.

12. A method as defined in claim 11 including the further steps of providing a third lead with first, second, and third spaced apart sensing electrodes.

13. A method as defined in claim 12 including the further steps of disposing said first, second, and third spaced apart sensing electrodes of said third lead within the right ventricle of the heart and sensing electrical activations of the heart with said first, second, and third sensing electrodes in the right ventricle.

14. A method as defined in claim 13 wherein said first electrode is disposed in the right atrial appendage of the heart.

15. A method as defined in claim 11 wherein said applying step includes applying said electrical energy in the form of a biphasic waveform having a pair of equal duration phases and a total energy between 0.5 and 2.1 joules.

16. A method as defined in claim 15 wherein each of said phases has a duration between 2 and 4 milliseconds.

17. A method as defined in claim 11 including the further step of providing a third lead with first and second spaced apart sensing electrodes.

18. A method as defined in claim 17 including the further steps of disposing said first and second spaced apart sensing electrodes of said third lead within the right ventricle of the heart and sensing electrical activations of the heart with said first and second sensing electrodes in the right ventricle.

19. A method as defined in claim 18 wherein said first electrode is disposed in the right atrial appendage of the heart.

20. A method as defined in claim 11 wherein said lead means providing step includes providing a preshaped bend in said second lead for fixing said second lead in the coronary sinus of the heart.

21. An implantable device for monitoring activity of the heart and delivering cardioverting electrical energy to the atria of the heart, said device comprising:

storage means for storing said electrical energy;

lead means coupled to said storage means for receiving said electrical energy from said storage means and applying said electrical energy between the right atrium of the heart and the coronary sinus beneath the left atrium of the heart for delivering said electrical energy to the atria of the heart, said lead means including a first lead having a first electrode arranged to be disposed within the right atrial appendage of the heart and a second lead including a second electrode arranged to be disposed within the coronary sinus beneath the left atrium of the heart for delivering said electrical energy to the atria of the heart;

atrial activity sensing means for sensing atrial activity of the heart, said atrial activity sensing means being coupled to said first and second electrodes; and

electrical activation sensing means for sensing electrical activations of the heart, said lead means including a third lead having first and second spaced apart sensing electrodes coupled to said electrical activation sensing means and for being disposed within the right ventricle of the heart,

wherein said second lead includes a preshaped bend in the region of said second lead within the coronary sinus for fixing said second lead within the coronary sinus,

said lead means being fully implantable beneath the skin of a patient.