摘要:
Disclosed is a system for the detection of cardiac events (a guardian system) that includes an implanted device called a cardiosaver, a physician's programmer and an external alarm system. The system is designed to provide early detection of cardiac events such as acute myocardial infarction or exercise induced myocardial ischemia caused by an increased heart rate or exertion. The system can also alert the patient with a less urgent alarm if a heart arrhythmia is detected. Using one or more detection algorithms, the cardiosaver can detect a change in the patient's electrogram that is indicative of a cardiac event within five minutes after it occurs and then automatically warn the patient that the event is occurring. To provide this warning, the guardian system includes an internal alarm sub-system (internal alarm means) within the cardiosaver and/or an external alarm system (external alarm means). If the guardian system is put into a pacemaker, the algorithm can utilize a different analysis of the electrogram depending on whether or not the pacemaker is actually pacing the heart.
摘要:
A physician's programmer for an implantable device is disclosed. The programmer includes a receiver for receiving wireless transmission data from the implantable heart monitor. A processor is configured to extract from the wireless transmission data ST-deviation histogram data as a function of heart rate. The histogram data for a particular heart rate range is shown on a display in the form of a bar chart. The histogram data for a plurality of heart rate ranges is shown in the form of a chart with multiple line plots.
摘要:
A system for the detection of cardiac events occurring in a human patient is provided. At least two electrodes are included in the system for obtaining an electrical signal from a patient's heart. An electrical signal processor is electrically coupled to the electrodes for processing the electrical signal and a patient alarm means is further provided and electrically coupled to the electrical signal processor. The electrical signal is acquired in the form of electrogram segments, which are categorized according to heart rate, ST segment shift and type heart rhythm (normal or abnormal). Baseline electrogram segments are tracked over time.
摘要:
A heart rate monitor is disclosed. The monitor generates an ST deviation time series by employing a recursive filter that is preferably an exponential average filter whose output is a weighted sum of the then existing ST time series value and current ST deviation values of analyzable beats, seats are detected in segments of data. ST deviation is measured for analyzable beats. The ST deviation time series is updated only if certain criteria are met. A first criterion for updating the time series is that at least half of the beats within a segment must be normal sinus rhythm beats: A second criterion for updating the time series is that (i) the average RR interval of the segment is between ¾ and 1.5 times the average RR interval of the previous segment; or (ii) both (a) the number of abnormal beats in the current segment is less than 2, and (b) the number of premature ventricular contractions within the current segment is less than 2.
摘要:
A heart monitor is disclosed. The monitor computes ST segment deviations and stores the results in heart rate based histograms. Periodically, the monitor analyzes the histogram data to determine heart rate dependent acute ischemia detection thresholds. If the statistical distribution associated with a heart rate range is insufficient, the threshold for that heart rate range is set as a function of the threshold for a neighboring heart rate range. Thresholds are also increased for heart rate ranges associated with statistical distributions that are sufficient but that have a relatively small number of entries.
摘要:
A heart monitor is disclosed. The monitor computes ST segment deviations and stores the results in heart rate based histograms. Periodically, the monitor analyzes the histogram data to determine a median value of ST deviation. Subsequently, beats are excluded from the computation of the time series if their ST deviations both varies too far from the long term median value and varies too far from the then current time series value.