Optimization of Pacemaker Settings with Electrogram

摘要

The system provides information to facilitate efficient optimization of programmer settings for cardiac pacemakers. It simultaneously measures a patient's electrogram (EGM) and peripheral blood pressure (or volumetric displacement) waveform in order to calculate, in real-time and non-invasively, a value correlated to the pre-ejection time (PET) and, optionally, ejection duration (ED) for the patient's left ventricle. The peripheral pulse waveform can be monitored with a wrist mounted tonometer, or a suitable brachial cuff device. The time difference between the occurrence of the first detected positive or negative peak in a patient's LV electrogram trace (EGM) and the foot of the pulse on the peripheral pulse waveform is defined as a surrogate pre-ejection time interval (SPET). Data including the electrogram and peripheral pulse trace, as well as the calculated, surrogate pre-ejection time interval (SPET) for each heart beat and trending is displayed on a computer monitor, thereby allowing a physician or nurse to quickly optimize PET for the patient and adjust programmer settings for an implanted pacemaker.

主权项

1. A method of optimizing one or more programmer settings of a cardiac pacemaker comprising the steps of:
attending to a patient with a cardiac pacemaker having one or more programmable settings wherein at least one pacing/sensing lead of the cardiac pacemaker is implanted in the patient's left ventricle muscle and senses a level of electrical depolarization of the left ventricle; monitoring the signal sensed by the lead and producing an LV electrogram that plots the amount of electrical depolarization of the left ventricle as a function of time such that local ventricular depolarization is characterized by a deflection in the time plot of the electrical depolarization on the LV electrogram; simultaneously using a sensor to measure a peripheral pulse waveform of the patient as a function of time; for each respective pulse, determining from the LV electrogram local depolarization of the contracting left ventricle and defining a time corresponding to the associated deflection as an LV impulse time (To) for the contracting ventricle; for each respective pulse, determining the realization of systolic onset in the detected peripheral pulse waveform and defining the corresponding time as a peripherally measured systolic onset time (T2) for the pulse; using T0 and T2 to calculate a surrogate pre-ejection time interval SPET for the pulse; presenting information related to the calculated surrogate pre-ejection interval (SPET); and adjusting one or more of the programmable settings for the cardiac pacemaker in an effort to optimize the value of the calculated surrogate pre-ejection time interval SPET for the patient.