Advanced cardiovascular monitoring system with normal, elevated, and high heartrate thresholds

Inventors

Fischell, David R. • John, Michael Sasha • Keenan, David • Johnson, Steve • Turi, Gregg

Assignees

Avertix Medical Inc

Abstract

A device for detecting acute coronary syndrome (ACS) events, arrythmias, heart rate abnormalities, medication problems such as non-compliance or ineffective amount or type of medication, and demand/supply related cardiac ischemia is disclosed. The device may have both implanted and external components and can communicate with other user devices such as smartphones and smartwatches for monitoring and alerting in response to detected medically relevant events or states of a patient. The processor is configured to provide event detection based upon various criteria including what is found to be statistically abnormal for a patient or what has been defined by a doctor to be abnormal. A patient's cardiovascular condition can be tracked over time using histogram, trend, and summary information related to heart rate and/or cardiac features such as those measured from the S-T segment of heartbeats. Heartbeats that are elevated but which are below what is defined as high, are used to provide medically relevant detections.

Core Innovation

A system for detecting a cardiac event in a human patient includes at least two electrodes implanted in the patient for obtaining an electrogram. The implanted cardiac monitoring system is devoid of circuitry adapted to deliver electrical energy through the electrodes, and includes analog-to-digital converter circuitry for digitizing the electrogram into electrogram segments having a time duration of at least 1 second. The system processes a first electrogram segment at a first predetermined time to extract at least one baseline heart signal parameter of the patient, and stores the baseline heart signal parameter in memory.

The system also stores lower and upper limits for a patient's normal heart rate range and an elevated heart rate range, with the lower limit of the elevated range at or above the upper limit of the normal range. The system processes a plurality of electrogram segments at a later, second predetermined time to extract at least one heart signal of the patient. A processor detects the cardiac event when the extracted heart rate signal shifts by more than a predetermined threshold amplitude from the baseline heart signal parameter extracted at the first predetermined time.

The processor computes the average heart rate of each electrogram segment. The processor identifies a prolonged period of elevated heart rate when the computed average heart rate is in the elevated heart rate range for at least 50% of electrogram segments over a pre-set time period. An implanted cardiac monitoring device is also described for monitoring the heart of a human patient using at least one implantable lead with at least one electrode for sensing electrical signals from the patient's heart, with electronic circuitry devoid of circuitry adapted to deliver electrical energy through the electrode and with digital memory storing pre-set lower and upper limits for normal and elevated heart rate ranges.

The processor is configured to detect abnormalities in patient heart rate selected from high heart rate, low heart rate, elevated heart rate defined by an elevation duration criterion, and irregular heart rate based on R-R interval relationships among beats during an irregular heart rate time period.

Claims Coverage

The provided material includes two independent claims. Both focus on heart-rate-based cardiac event or abnormality detection using implanted electrodes or leads, digitized electrogram or electrical signals, and comparisons to stored baseline or stored heart-rate limits over time. Across the independent claims, the inventive features center on baseline extraction and threshold-shift cardiac event detection with a prolonged-elevated-heart-rate criterion, and implanted device detection of selected heart-rate abnormalities including irregularity defined using R-R interval relationships and time-period criteria.

Across the independent claims, the coverage centers on implanted sensing with digitization, storage of patient-specific baseline or stored normal and elevated heart rate limits, and processor-based detection over time. Claim coverage includes detecting a cardiac event based on a threshold amplitude shift from a stored baseline heart signal parameter and detecting selected heart-rate abnormalities including irregular heart rate based on R-R interval relationships during defined time periods.

Stated Advantages

Documented Applications