Automatic adjusting R-wave synchronization algorithm for atrial cardioversion and defibrillation
First Claim
1. A method of controlling a therapy in an implantable medical device, comprising:
- setting a refractory period upper limit;
setting a lower limit for the refractory period;
initializing a refractory period to the refractory period upper limit;
sensing a cardiac signal other than during the refractory period and determining whether to deliver a therapy in response to the cardiac signal;
determining whether an R-wave synchronization criteria for delivering the therapy are met; and
thenif the R-wave synchronization criteria are met, delivering the therapy and returning to the sensing step; and
if the R-wave synchronization criteria are not met, automatically adjusting the refractory period to be less than the refractory period upper limit and return to the sensing step;
determining whether the refractory period, as adjusted, is less than the lower limit;
terminating the method in response to the refractory period, as adjusted, being less than the lower limit;
determining, in response to the refractory period, as adjusted, not being less than the lower limit, whether the R-wave synchronization criteria corresponding to the refractory period, as adjusted, are met for a subsequently sensed cardiac signal;
delivering the therapy in response to the R-wave synchronization criteria being met for the subsequently sensed cardiac signals; and
automatically adjusting the refractory period, as adjusted, in response to the R-wave synchronization criteria not being met.
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Abstract
An implantable medical device system and method are provided for synchronizing atrial cardioversion shocks to the ventricular rhythm using an adjustable atrial cardioversion/defibrillation ventricular refractory period. Upon determining a need for an atrial shock therapy, the method determines if the ventricular rate meets synchronization criteria based on an upper ventricular refractory period limit. If synchronization criteria are not met, the refractory period is automatically adjusted in stepwise decrements until the synchronization criteria are met, or until a lower refractory period limit is exceeded. If synchronization criteria are met, an atrial shock is synchronized to the next ventricular depolarization occurring outside the current refractory period. If the lower refractory period limit is exceeded, the atrial therapy is aborted.
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Citations
17 Claims
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1. A method of controlling a therapy in an implantable medical device, comprising:
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setting a refractory period upper limit; setting a lower limit for the refractory period; initializing a refractory period to the refractory period upper limit; sensing a cardiac signal other than during the refractory period and determining whether to deliver a therapy in response to the cardiac signal; determining whether an R-wave synchronization criteria for delivering the therapy are met; and
thenif the R-wave synchronization criteria are met, delivering the therapy and returning to the sensing step; and if the R-wave synchronization criteria are not met, automatically adjusting the refractory period to be less than the refractory period upper limit and return to the sensing step; determining whether the refractory period, as adjusted, is less than the lower limit; terminating the method in response to the refractory period, as adjusted, being less than the lower limit; determining, in response to the refractory period, as adjusted, not being less than the lower limit, whether the R-wave synchronization criteria corresponding to the refractory period, as adjusted, are met for a subsequently sensed cardiac signal; delivering the therapy in response to the R-wave synchronization criteria being met for the subsequently sensed cardiac signals; and automatically adjusting the refractory period, as adjusted, in response to the R-wave synchronization criteria not being met. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An implantable medical device, comprising:
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means for setting a refractory period upper limit; means for initializing a refractory period to the refractory period upper limit; means for sensing cardiac signals other than during the refractory period and determining whether to deliver a therapy in response to the sensed cardiac signals; means for determining whether R-wave synchronization criteria for delivering the therapy are met; means for delivering the therapy in response to the synchronization criteria being met; and means for automatically adjusting the refractory period in response to the synchronization criteria not being met; means for setting a lower limit for the refractory period and wherein the determining means determines whether the refractory period, as adjusted, is less than a lower limit, and determines, in response to the refractory period, as adjusted, not being less than the lower limit, whether the synchronization criteria corresponding to the refractory period, as adjusted, are met for subsequently sensed cardiac signals, the delivery means delivers the therapy in response to the synchronization criteria being met for the subsequently sensed cardiac signals, and the adjusting means adjusts the refractory period, as adjusted, in response to the synchronization criteria not being met. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17)
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Specification