US 5,458,623 A · Automatic atrial pacing threshold determination utilizing an external programmer and a surface electrogram

Abstract

A clinical programming system for use with an implanted cardiac pacemaker to automatically determine the minimum pacing energy which is necessary to evoke an atrial depolarization. The system utilizes a series of pacing pulses of progressively decreasing energies to stimulate the atrium, and detects an evoked response during the AV delay interval that follows each pulse. Initial P-wave intervals are subjected to morphological analysis to generate a P-wave template. Subsequent intervals are similarly analyzed and the results compared with the template. The absence of similarity with the template indicates the loss of atrial capture and that the minimum pacing energy has been reached.

Claims17

Dependent claims

A method of determining a minimum energy of a pacing pulse necessary to evoke an atrial depolarization response in the heart of a patient, comprising the steps of:

(a) generating a series of test atrial pacing pulses of sequentially decreasing energy;
obtaining a surface electrogram representing evoked atrial responses to said atrial pacing pulses;
each evoked atrial response being characterized by a corresponding morphology;
(c) performing morphological analyses on an initial plurality of evoked atrial responses and generating a morphology template of the results of said analyses;
(d) comparing the morphology of each subsequent evoked test atrial response with said template and, if they are similar, then repeating steps (b) and (c) for the next evoked test atrial response;
and
(e) concluding that a minimum energy may have been determined when the morphology of an evoked test atrial response is not similar to said template.

4 more elements

A method of determining a minimum energy of a pacing pulse necessary to evoke an atrial depolarization response in the heart of a patient comprising the steps of:

(a) generating a first test atrial pacing pulse of pre-determined energy;
(b) obtaining a surface electrogram representing a first evoked atrial response to said first test atrial pacing pulse;
(c) storing the evoked atrial response of said first test atrial pacing pulse;
(d) generating a second test atrial pacing pulse of pre-determined energy;
(e) obtaining another surface electrogram representing a second evoked atrial response to said second test atrial pacing pulse;
(f) performing morphological analysis of the evoked atrial responses which followed said first and second test atrial pacing pulses;
(g) determining whether the morphological analysis results of the first and second evoked atrial responses are similar and, if similar, then deriving and storing a P-wave template of the combined morphological analysis results;
(h) generating a series of test atrial pulses of sequentially decreasing energy;
(i) comparing a morphology of each atrial response evoked by a test pulse in said series with said template and, if they are similar, then repeating steps g and h for the next evoked test atrial response;
and
(j) concluding that a minimum energy has been determined when the morphology of an evoked test atrial response is not similar to said template.

8 more elements

Dependencies are inferred from the claim text.

Automatic atrial pacing threshold determination utilizing an external programmer and a surface electrogram

Life of this patent

Automatic atrial pacing threshold determination utilizing an external programmer and a surface electrogram

Life of this patent

Abstract

Claims17