Implantable stimulation device and method for determining atrial autocapture using programmable AV delay
First Claim
1. A method of determining an atrial capture threshold in a stimulation device having a programmable AV delay, the method comprising:
- generating an atrial stimulation pulse;
detecting loss of capture of the atrial stimulation pulse; and
in response to the loss of capture, automatically shortening the AV delay in a subsequent cardiac cycle to reduce the possibility of a retrograde P-wave initiating a tachycardia event.
1 Assignment
0 Petitions
Accused Products
Abstract
A pacemaker programmer and diagnostic system retrieves information stored within a pacemaker and analyzes the retrieved data in real time. The stored information can be retrieved by means of a telemetry communication link. The pacemaker automatically lengthens a post-ventricular atrial refractory period (PVARP). The pacemaker determines atrial capture threshold by generating atrial stimulation pulses while maintaining the ventricular stimulation pulse amplitude at a level known to ensure ventricular capture, and by detecting loss of atrial capture. In response to the loss of atrial capture, a processor automatically shortens the AV delay in a subsequent cardiac cycle, to reduce the possibility of a retrograde P-wave initiating a pacemaker-mediated tachycardia (PMT). Also in response to the loss of atrial capture, the pacemaker records the atrial capture threshold, restores the PVARP to its pre-test value, and sets the atrial stimulation pulse amplitude to a value above the atrial capture threshold.
-
Citations
26 Claims
-
1. A method of determining an atrial capture threshold in a stimulation device having a programmable AV delay, the method comprising:
-
generating an atrial stimulation pulse;
detecting loss of capture of the atrial stimulation pulse; and
in response to the loss of capture, automatically shortening the AV delay in a subsequent cardiac cycle to reduce the possibility of a retrograde P-wave initiating a tachycardia event. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
restoring the PVARP to a base value; and
restoring the atrial stimulation pulse to a base amplitude.
-
-
16. A stimulation device for determining an atrial capture threshold and having a programmable AV delay, comprising:
-
a pulse generator for generating an atrial stimulation pulse;
detection circuitry coupled to the pulse generator for detecting loss of capture of the atrial stimulation pulse; and
a processor, coupled to the pulse generator and the detection circuitry, for automatically shortening the AV delay in a subsequent cardiac cycle, in response to the loss of capture, to reduce the possibility of a retrograde P-wave initiating a tachycardia event. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23)
wherein the processor retrieves the historical data; and
wherein based on the historical data, the processor estimates an atrial stimulation pulse amplitude at which loss of capture would occur, and sets the amplitude of the initial atrial stimulation pulse to a predetermined level above the estimated atrial stimulation pulse amplitude.
-
-
18. The stimulation device, as recited in claim 16, wherein the detecting circuitry detects loss of capture by adjusting an amplitude of the atrial stimulation pulse until loss of capture occurs.
-
19. The stimulation device, as recited in claim 16, further including a programmable post-ventricular refractory period (PVARP);
- and
wherein the processor includes timing circuitry for lengthening the PVARP before detecting loss of capture, to reduce the possibility of premature and retrograde P-waves being detected as true cardiac contractions.
- and
-
20. The stimulation device, as recited in claim 19, wherein if the detection circuitry does not detect loss of capture, the timing circuitry decreases an atrial stimulation pulse amplitude until loss of capture is detected.
-
21. The stimulation device, as recited in claim 19, wherein the processor includes control circuitry;
-
wherein if loss of capture is detected, the control circuitry sets a capture threshold as the atrial stimulation pulse amplitude at which loss of capture occurs; and
wherein the control circuitry sets the atrial stimulation pulse amplitude to a value above the capture threshold.
-
-
22. The stimulation device, as recited in claim 19, wherein the timing circuitry restores the PVARP to a base value in response to loss of capture.
-
23. The stimulation device, as recited in claim 16, wherein the stimulation device is a dual-chamber implantable cardiac pacing device.
-
24. A stimulation device for determining an atrial capture threshold and having a programmable AV delay, comprising:
-
pulse generator for generating an atrial stimulation pulse;
detection means coupled to the pulse generator, detecting loss of capture of the atrial stimulation pulse; and
processing means, coupled to the pulse generator and the detection means, for automatically shortening the AV delay in a subsequent cardiac cycle, in response to the loss of capture, to reduce the possibility of a retrograde P-wave initiating a pacemaker-mediated tachycardia. - View Dependent Claims (25, 26)
wherein the processing means includes timing means for lengthening the PVARP before the detection of loss of capture, to reduce the possibility of premature and retrograde P-waves being detected as true cardiac contractions.
-
Specification