Implantable-defibrillator pulse detection-triggered ecg monitoring

Abstract

Ambulatory ECG data monitoring and recording method and apparatus that selectively captures recorded data based upon the occurrence of a defibrillation pulse from an implantable cardioverter/defibrillator monitor (ICDM) device is described. The apparatus uses a single pair of skin electrodes to sample the ECG signal waveform and to monitor the voltage therebetween for the detection of a ICDM-produced pulse of characteristic amplitude and duration. ECG data are continuously stored in a scrolling buffer of limited depth. Detection of a defibrillation pulse is treated as a trigger event, prompting the continuation of ECG data storage only for a limited further period of time after which the present ECG data record is captured. The buffered data are marked by the occurrence of the defibrillation pulse that prompted their capture, so that the information stored for subsequent playback indicates the timing relationship therebetween. A new buffer is initialized and ECG data recording and defibrillation pulse detection continues. Selectively capture-stored and marked ECG data can be played back to a remote site for diagnosis of a relatively longterm, ambulatory cardiac patient monitoring and recording session. Optionally, the cardiac patient may manually trigger the capture-store of ECG data.