Optimization of pacemaker settings with R-wave detection

摘要

The system provides information to facilitate efficient optimization of programmer settings for cardiac pacemakers. It simultaneously measures a patient's electrocardiogram 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 R-wave on the ECG trace and the foot of the pulse on the radial blood pressure waveform is defined as a surrogate pre-ejection time interval (SPET). Data including the electrocardiogram 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; measuring the electrical activity of a heart of the patient in the form of an electrocardiogram which plots a sensed voltage difference between electrodes placed noninvasively in the patient's skin as a function of time, for each pulse of the heart, the electrocardiogram being characterized in part by a QRS complex having an R-wave; 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 electrocardiogram the R-wave of the QRS complex and defining a time corresponding to the R-wave as an R-wave impulse time (TR) for a 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 TR and T2 to calculate an R-wave surrogate pre-ejection time interval SPET for the pulse; presenting information related to the calculated R-wave 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.