Method and apparatus for dual chamber cardiac pacing
First Claim
1. A method of pacing a heart, comprising:
- detecting atrial and ventricular depolarizations;
measuring atrial--ventricular conduction time of said heart;
delivering ventricular pacing pulses capable of completely capturing said heart'"'"'s ventricles absent concurrent spontaneous depolarizations of said ventricles;
determining a time interval following an atrial depolarization of said heart, such that a ventricular pacing pulse delivered at expiration of said time interval results in complete ventricular capture of said heart;
deriving a first offset interval based on relative durations of said determined time interval and said measured atrial--ventricular conduction time;
defining A-V escape intervals following atrial depolarizations;
delivering ventricular pacing pulses at the expirations of said A-V escape intervals absent ventricular depolarizations during said A-V escape intervals;
measuring atrial--ventricular conduction time of a ventricular depolarization occurring within a said A-V escape interval; and
defining duration of a subsequent said A-V escape interval based on said first offset interval and said atrial--ventricular conduction time measured within said A-V escape interval.
1 Assignment
0 Petitions
Accused Products
Abstract
A dual chamber pacemaker and a method of employing the pacemaker to accomplish atrial synchronized ventricular pacing with complete ventricular capture by control of the A-V escape intervals of the pacer. The maximum A-V escape interval effective to accomplish complete ventricular capture is determined and compared to intrinsic A-V conduction time to derive an offset interval. The offset interval is subtracted from the initially measured conduction time to select initial A-V escape interval durations and is subtracted from A-V conduction times measured after implant of the pacemaker to automatically adjust A-V escape interval durations of the pacemaker to maintain complete ventricular capture.
-
Citations
19 Claims
-
1. A method of pacing a heart, comprising:
-
detecting atrial and ventricular depolarizations; measuring atrial--ventricular conduction time of said heart; delivering ventricular pacing pulses capable of completely capturing said heart'"'"'s ventricles absent concurrent spontaneous depolarizations of said ventricles; determining a time interval following an atrial depolarization of said heart, such that a ventricular pacing pulse delivered at expiration of said time interval results in complete ventricular capture of said heart; deriving a first offset interval based on relative durations of said determined time interval and said measured atrial--ventricular conduction time; defining A-V escape intervals following atrial depolarizations; delivering ventricular pacing pulses at the expirations of said A-V escape intervals absent ventricular depolarizations during said A-V escape intervals; measuring atrial--ventricular conduction time of a ventricular depolarization occurring within a said A-V escape interval; and defining duration of a subsequent said A-V escape interval based on said first offset interval and said atrial--ventricular conduction time measured within said A-V escape interval. - View Dependent Claims (8, 9)
-
-
2. A method of pacing a heart, comprising:
-
detecting atrial and ventricular depolarizations; measuring atrial--ventricular conduction time of said heart; delivering ventricular pacing pulses capable of completely capturing said heart'"'"'s ventricles absent concurrent spontaneous depolarizations of said ventricles; determining a time interval following an atrial depolarization of said heart, such that a ventricular pacing pulse delivered at expiration of said time interval results in complete ventricular capture of said heart; deriving a first offset interval based on relative durations of said determined time interval and said measured atrial--ventricular conduction time; defining an A-V escape intervals following atrial depolarizations; delivering ventricular pacing pulses at the expirations of said A-V escape intervals absent ventricular depolarizations during said A-V escape intervals; extending durations of said A-V escape intervals until a ventricular depolarization falls within a said extended A-V escape interval; measuring atrial--ventricular conduction time of a ventricular depolarization occurring within a said extended A-V escape interval; and defining duration of a subsequent said A-V escape interval based on said first offset interval and said atrial--ventricular conduction time measured within said extended A-V escape interval. - View Dependent Claims (3, 4)
-
-
5. A method of pacing a heart, comprising:
-
sensing atrial depolarizations; delivering a ventricular pacing pulse to said heart to induce complete ventricular capture;
"determining a ventricular depolarization waveform caused by said ventricular pacing pulse and indicative of complete ventricular capture;
"defining A-V escape intervals following atrial depolarizations; delivering ventricular pacing pulses at expirations of said A-V escape intervals; varying durations of said A-V intervals while monitoring waveforms of ventricular depolarizations following said ventricular pacing pulses to define an A-V escape interval such that a ventricular pacing pulse delivered at expiration of said defined A-V escape interval results in complete ventricular capture of said heart; and employing said defined A-V escape interval to control durations of subsequent A-V escape intervals. - View Dependent Claims (6, 7)
-
-
10. Apparatus for pacing a heart, comprising:
-
means for sensing atrial depolarizations; means for defining a first offset interval; means for defining A-V escape intervals following atrial depolarizations; means for sensing ventricular depolarizations of said heart; means for delivering ventricular pacing pulses at the expirations of said A-V escape intervals in the absence of ventricular depolarizations during said A-V escape intervals; means for extending durations of said A-V escape intervals until a ventricular depolarization falls within a said extended A-V escape interval; means for measuring atrial--ventricular conduction time of a sensed ventricular depolarization occurring within a said extended A-V escape interval; and means for defining duration of a subsequent said A-V escape interval by subtracting said first offset interval and said atrial--ventricular conduction time measured within said extended A-V escape intervail; wherein said means for extending said A-V escape intervals comprises means for extending said A-V escape intervals up to a predefined maximum A-V escape interval, and further comprises means for preventing subsequent extensions of said A-V escape intervals for a period of time in response to failure of a ventricular depolarization to occur within said maximum A-V escape interval. - View Dependent Claims (11, 12, 13, 14)
-
-
15. Apparatus for pacing a heart, comprising:
-
means for sensing atrial and ventricular depolarizations; means for measuring atrial--ventricular conduction time of said heart; means for delivering ventricular pacing pulses capable of completely capturing said heart'"'"'s ventricles absent concurrent spontaneous depolarizations of said ventricles; means for determining a time interval following an atrial depolarization of said heart, such that a said ventricular pacing pulse delivered at expiration of said time interval results in complete ventricular capture of said heart; means for deriving a first offset interval based on relative durations of said determined time interval and said measured atrial--ventricular conduction time; means for defining A-V escape intervals following atrial depolarizations; means for sensing ventricular depolarizations of said heart; delivering ventricular pacing pulses at the expirations of said A-V escape intervals absent sensed ventricular depolarizations during said A-V escape intervals; means for measuring atrial--ventricular conduction time of a ventricular depolarization occurring within a said A-V escape interval; and means for defining duration of a subsequent said A-V escape interval based on said first offset interval and said atrial--ventricular conduction time measured within said A-V escape interval.
-
-
16. Apparatus for pacing a heart, comprising:
-
means for sensing atrial and ventricular depolarizations; means for measuring atrial--ventricular conduction time of said heart; means for delivering ventricular pacing pulses capable of completely capturing said heart'"'"'s ventricles absent concurrent spontaneous depolarizations of said ventricles; means for determining a time interval following an atrial depolarization of said heart, such that a ventricular pacing pulse delivered at expiration of said time interval results in complete ventricular capture of said heart; means for deriving a first offset interval based on relative durations of said determined time interval and said measured atrial--ventricular conduction time; means for defining an A-V escape intervals following atrial depolarizations; means for sensing ventricular depolarizations of said heart; means for delivering ventricular pacing pulses at the expirations of said A-V escape intervals absent ventricular depolarizations during said A-V escape intervals; means for extending durations of said A-V escape intervals until a sensed ventricular depolarization falls within a said extended A-V escape interval; means for measuring atrial--ventricular conduction time of a sensed ventricular depolarization occurring within a said extended A-V escape interval; and means for defining duration of a subsequent said A-V escape interval based on said first offset interval and said atrial--ventricular conduction time measured within said extended A-V escape interval.
-
-
17. Apparatus for pacing a heart, comprising:
-
means for sensing atrial and ventricular depolarizations; means for delivering a ventricular pacing pulse to said heart to induce complete ventricular capture; means for delivering ventricular pacing pulses capable of completely capturing said heart'"'"'s ventricles absent concurrent spontaneous depolarizations of said ventricles; means for monitoring waveforms of ventricular depolarizations; means for determining a ventricular depolarization waveform indicative of complete ventricular capture; means for defining A-V escape intervals following atrial depolarizations; means for delivering said ventricular pacing pulses at expirations of said A-V escape intervals; means for varying durations of said A-V intervals while monitoring waveforms of ventricular depolarizations following said ventricular pacing pulses; means responsive to said monitoring means, for identifying a said A-V escape interval duration such that a ventricular pacing pulse delivered at expiration of said identified A-V escape interval duration results in complete ventricular capture of said heart; and means for employing said identified A-V escape interval duration to define durations of subsequent said A-V escape intervals. - View Dependent Claims (18, 19)
-
Specification