Apparatus and method for detecting, confirming and terminating pacemaker mediated tachycardia

Claim 3

A method in accordance with claim 1 wherein in step (d) the presence of PMT is confirmed only if atrial beats are not sensed at the ends of all of the measured intervals following said several approximately simultaneous atrial contractions and ventricular pacing pulses.

Claim 4

A method in accordance with claim 2 wherein in step (b) a first V-pace-to-A-sense (VP-to-AS) interval is measured for one ventricular pacing pulse, and it is determined whether X out of Y VP-to-AS intervals are within a window around said one VP-to-AS interval.

Claim 5

A method in accordance with claim 3 wherein Y=X+1.

Claim 6

A method in accordance with claim 4 wherein, prior to confirming the presence of PMT, the possibility of its presence is suspected by the sudden onset of a fast rate together with the rate being higher than the expected physiological rate by a predetermined percentage.

Claim 7

A method in accordance with claim 1 wherein in step (b) a first V-pace-to-A-sense (VP-to-AS) interval is measured for one ventricular pacing pulse, and it is determined whether X out of Y VP-to-AS intervals are within a window around said one VP-to-AS interval.

Claim 8

A method in accordance with claim 6 wherein Y=X+1.

Claim 9

A method in accordance with claim 7 wherein, prior to confirming the presence of PMT, the possibility of its presence is suspected by the sudden onset of a fast rate together with the rate being higher than the expected physiological rate by a predetermined percentage.

Claim 10

A method in accordance with claim 6 wherein, prior to confirming the presence of PMT, the possibility of its presence is suspected by the sudden onset of a fast rate together with the rate being higher than the expected physiological rate by a predetermined percentage.

Claim 11

A method in accordance with claim 1 wherein, prior to confirming the presence of PMT, the possibility of its presence is suspected by the sudden onset of a fast rate together with the rate being higher than the expected physiological rate by a predetermined percentage.

Claim 14

A method in accordance with claim 11 wherein in step (d) the presence of PMT is confirmed only if atrial beats are not sensed at the ends of all of the measured intervals following the pacing expected to preclude retrograde conduction.

Claim 15

A method in accordance with claim 12 wherein in step (b) a first V-pace-to-A-sense (VP-to-AS) interval is measured for one ventricular pacing pulse, and it is determined whether X out of Y VP-to-AS intervals are within a window around said one VP-to-AS interval.

Claim 16

A method in accordance with claim 13 wherein Y=X+1.

Claim 17

A method in accordance with claim 14 wherein, prior to confirming the presence of PMT, the possibility of its presence is suspected by the sudden onset of a fast rate together with the rate being higher than the expected physiological rate by a predetermined percentage.

Claim 18

A method in accordance with claim 11 wherein in step (b) a first V-pace-to-A-sense (VP-to-AS) interval is measured for one ventricular pacing pulse, and it is determined whether X out of Y VP-to-AS intervals are within a window around said one VP-to-AS interval.

Claim 19

A method in accordance with claim 16 wherein Y=X+1.

Claim 20

A method in accordance with claim 17 wherein, prior to confirming the presence of PMT, the possibility of its presence is suspected by the sudden onset of a fast rate together with the rate being higher than the expected physiological rate by a predetermined percentage.

Claim 21

A method in accordance with claim 16 wherein, prior to confirming the presence of PMT, the possibility of its presence is suspected by the sudden onset of a fast rate together with the rate being higher than the expected physiological rate by a predetermined percentage.

Claim 22

A method in accordance with claim 11 wherein, prior to confirming the presence of PMT, the possibility of its presence is suspected by the sudden onset of a fast rate together with the rate being higher than the expected physiological rate by a predetermined percentage.

Claim 23

An implantable pacemaker which automatically detects and confirms the presence of, and terminates, pacemaker mediated tachycardia (PMT) comprising: (a) means for generating ventricular pacing pulses, (b) means for measuring the interval between a generated ventricular pacing pulse and the succeeding sensed atrial beat (VP-to-AS interval), and for repeating said interval measurement on at least one subsequent VP-to-AS interval, (c) means for detecting PMT by determining whether the measured intervals are consistent, (d) means responsive to the measured intervals being consistent for generating several ventricular pacing pulses approximately simultaneously with atrial contractions, (e) means for confirming that PMT is present only if, while said several ventricular pacing pulses are being generated, atrial beats are not sensed at the ends of measured intervals consistent with the intervals measured by said measuring means, and (f) means responsive to the presence of PMT being confirmed for extending the pacemaker PVARP to exceed the longest VP-to-AS interval measured by said measuring means.

Claim 24

An implantable pacemaker which automatically detects and confirms the presence of, and terminates, pacemaker mediated tachycardia (PMT) comprising: (a) means for generating ventricular pacing pulses, (b) means for measuring the interval between a generated ventricular pacing pulse and the succeeding sensed atrial beat (VP-to-AS interval), and for repeating said interval measurement on at least one subsequent VP-to-AS interval, (c) means for detecting PMT by determining whether the measured intervals are consistent, (d) means responsive to the measured intervals being consistent for generating several ventricular pacing pulses approximately simultaneously with atrial contractions, (e) means for confirming that PMT is present only if, while said several ventricular pacing pulses are being generated, atrial beats are not sensed at the ends of measured intervals consistent with the intervals measured by said measuring means, and (f) means responsive to the presence of PMT being confirmed for extending the pacemaker PVARP to exceed the longest VP-to-AS interval measured by said measuring means.

Claim 25

An implantable pacemaker in accordance with claim 21 wherein said confirming means is operative to confirm the presence of PMT only if atrial beats are not sensed at the ends of all of the measured intervals following said several ventricular pacing pulses.

Claim 26

An implantable pacemaker in accordance with claim 21 wherein said determining means operates to determine whether X out of Y VP-to-AS intervals following one VP-to-AS interval are within a window around said one VP-to-AS interval.

Claim 27

An implantable pacemaker in accordance with claim 23 wherein Y=X+1.

Claim 28

An implantable pacemaker in accordance with claim 21 further including means for suspecting the possible presence of PMT by the sudden onset of a fast rate together with the rate being higher than the expected physiological rate by a predetermined percentage, and means for enabling the automatic confirmation and termination of PMT only responsive to operation of said suspecting and detecting means.

Claim 29

An implantable pacemaker which automatically detects and confirms the presence of pacemaker mediated tachycardia (PMT) comprising: (a) means for generating ventricular pacing pulses, (b) means for measuring the interval between a generated ventricular pacing pulse and the succeeding sensed atrial beat (VP-to-AS interval), and for repeating said interval measurement on at least one subsequent VP-to-AS interval, (c) means for detecting PMT by determining whether the measured intervals are consistent, (d) means responsive to the measured intervals being consistent for pacing the patient's heart in a manner expected to preclude retrograde conduction, and (e) means for confirming that PMT is present only if, while said pacing means operates in a manner expected to preclude retrograde conduction, the pattern of atrial beats sensed is markedly different from the pattern of atrial beats operated on by said measuring means.

Claim 30

An implantable pacemaker which automatically detects and confirms the presence of pacemaker mediated tachycardia (PMT) comprising: (a) means for generating ventricular pacing pulses, (b) means for measuring the interval between a generated ventricular pacing pulse and the succeeding sensed atrial beat (VP-to-AS interval), and for repeating said interval measurement on at least one subsequent VP-to-AS interval, (c) means for detecting PMT by determining whether the measured intervals are consistent, (d) means responsive to the measured intervals being consistent for pacing the patient's heart in a manner expected to preclude retrograde conduction, and (e) means for confirming that PMT is present only if, while said pacing means operates in a manner expected to preclude retrograde conduction, the pattern of atrial beats sensed is markedly different from the pattern of atrial beats operated on by said measuring means.

Claim 31

An implantable pacemaker in accordance with claim 26 wherein said confirming means is operative to confirm the presence of PMT only if atrial beats are not sensed at the ends of all measured intervals following pacing of the patient's heart by said means for pacing in a manner expected to preclude retrograde conduction.

Claim 32

An implantable pacemaker in accordance with claim 26 wherein said determining means operates to determine whether X out of Y VP-to-AS intervals following one VP-to-AS interval are within a window around said one VP-to-AS interval.

Claim 33

An implantable pacemaker in accordance with claim 28 wherein Y=X+1.

Claim 34

An implantable pacemaker in accordance with claim 26 further including means for suspecting the possible presence of PMT by the sudden onset of a fast rate together with the rate being higher than the expected physiological rate by a predetermined percentage, and means for enabling the automatic confirmation and termination of PMT only responsive to operation of said suspecting and detecting means.