Using an implantable antitachycardia defibrillator circuit

Claim 2

Cardiac stimulation apparatus, which comprises: an implantable cardiac pacer having an antitachycardia circuit for GM lowering a patient's electrical heart rate; an implantable defibrillator circuit; energy source means for said pacer and said defibrillator circuit; means for coupling said energy source means to said pacer and defibrillator circuit; first means for connecting said pacer to a patient's heart; second means for connecting said defibrillator circuit to the patient's heart; means coupled to the patient's heart and at least one of said circuits for sensing the patient's electrical heart rate; switching means coupled to said first connecting means and said second connecting means, said switching means being operative for isolating the cardiac pacer from the defibrillator circuit during operation of the defibrillator circuit.

Claim 3

Cardiac stimulation apparatus as described in claim 1, including means coupled to said sensing means and responsive to said electrical heart rate sensing means for activating said antitachycardia circuit if the electrical heart rate exceeds a predetermined threshold.

Claim 4

Cardiac stimulation apparatus as described in claim 2, including means coupled to the defibrillator circuit for activating said defibraillator circuit if said antitachycardia circuit fails to lower the electrical heart rate to below a selected rate.

Claim 5

Cardiac stimulation apparatus as described in claim 3, including means coupled to said defibrillator circuit for discontinuing activation of said defibrillator circuit if the patient's electrical heart rate lowers below said selected rate after the defibrillator circuit is activated.

Claim 6

Cardiac stimulation apparatus as described in claim 1, including signal means for providing signals between the pacer and the defibrillator circuit for controlling said switching means.

Claim 7

Cardiac stimulation apparatus as described in claim 5, said signals comprising a coded pulse train that is transmitted into the patient's tissue via said connecting means.

Claim 8

Cardiac stimulation apparatus as described in claim 1, in which said first connecting means comprises an electrical lead from the pacer to the patient's heart.

Claim 9

Cardiac stimulation apparatus as described in claim 1, in which said second connecting means comprises an electrical lead from the defibrillator circuit to the patient's heart.

Claim 10

Cardiac stimulation apparatus, which comprises: an implantable cardiac pacer having an antitachycardia circuit for GM lowering a patient's electrical heart rate; an implantable defibrillator circuit; energy source means for said pacer and said defibrillator circuit; means for coupling said energy source means to said pacer and said defibrillator circuit; a first electrical lead from the pacer to the patient's heart; a second electrical lead from the defibrillator circuit to the patient's heart; means coupled to the patient's heart and at least one of said circuits for sensing the patient's electrical heart rate; switching means coupled to said first lead and said second lead, said switching means being operative for isolating the cardiac pacer from the defibrillator circuit during operation of the defibrillator circuit; means coupled to said sensing means and responsive to said electrical heart rate sensing means for activating said antitachycardia circuit if the electrical heart rate exceeds a predetermined threshold; means coupled to said defibrillator circuit for activating said defibrillator circuit if said antitachycardia circuit fails to lower the electrical heart rate to below a selected rate; signal means for providing signals between the pacer and the defibrillator circuit for controlling said switching means, said signals comprising a coded pulse train that is transmitted into the patient's tissue via one of said leads; and means coupled to the defibrillator circuit for discontinuing activation of said defibrillation circuit if the patient's electrical heart rate lowers below said selected rate after the defibrillation circuit is activated.

Claim 11

Cardiac stimulation apparatus, which comprises: an implantable cardiac pacer having an antitachycardia circuit for GM lowering a patient's electrical heart rate; an implantable defibrillator circuit; energy source means for said pacer and said defibrillator circuit; means for coupling said energy source means to said pacer and said defibrillator circuit; a first electrical lead from the pacer to the patient's heart; a second electrical lead from the defibrillator circuit to the patient's heart; means coupled to the patient's heart and at least one of said circuits for sensing the patient's electrical heart rate; switching means coupled to said first lead and said second lead, said switching means being operative for isolating the cardiac pacer from the defibrillator circuit during operation of the defibrillator circuit; means coupled to said sensing means and responsive to said electrical heart rate sensing means for activating said antitachycardia circuit if the electrical heart rate exceeds a predetermined threshold; means coupled to said defibrillator circuit for activating said defibrillator circuit if said antitachycardia circuit fails to lower the electrical heart rate to below a selected rate; signal means for providing signals between the pacer and the defibrillator circuit for controlling said switching means, said signals comprising a coded pulse train that is transmitted into the patient's tissue via one of said leads; and means coupled to the defibrillator circuit for discontinuing activation of said defibrillation circuit if the patient's electrical heart rate lowers below said selected rate after the defibrillation circuit is activated.

Claim 14

A method as described in claim 10, further comprising providing switching means, said isolating step then comprising the step of providing signals between the pacer and the defibrillator circuit to control said switching means.

Claim 15

A method as described in Claim 10, further comprising providing switching means, said isolating step then comprising the step of transmitting a coded pulse train into the patient's tissue to control said switching means.

Claim 16

A method as described in claim 10, including the step of transmitting a signal to the defibrillator circuit if the antitachycardia circuit fails to lower the electrical heart rate to below a selected rate.

Claim 17

A method as described in claim 10, including the steps of providing switching means for isolating the antitachycardia circuit from the defibrillator circuit; operating the switch means in a first mode to isolate the antitachycardia circuit from the defibrillator circuit and in a second mode to enable the pacer to operate after the defibrillator has provided an appropriate defibrillating voltage.