摘要:
Heart failure decompensation is detected by sensing at least one physiological signal. Values of at least two different heart failure variables are derived using one or more physiological signals and a threshold for the first heart failure variable is adjusted in response to the value of the second heart failure variable. The value of the first heart failure variable is compared to first threshold for detecting a heart failure condition.
摘要:
Heart failure decompensation is detected by sensing at least one physiological signal. Values of at least two different heart failure variables are derived using one or more physiological signals and a threshold for the first heart failure variable is adjusted in response to the value of the second heart failure variable. The value of the first heart failure variable is compared to first threshold for detecting a heart failure condition.
摘要:
Techniques for estimating a cardiac chamber or vascular pressure based upon impedance are described. A device or system may measure an impedance between at least two electrodes implanted within or proximate to a cardiovascular system. The device or system may estimate a pressure of an element of the cardiovascular system based on a relationship between impedance and volume of the element, and based on a empirical relationship between the volume and the pressure. The device or system may also estimate the dimension of the element based on the impedance-volume relationship, or other characteristics based on the impedance. Because the impedance measurements may be obtained, in some examples, by using electrodes and leads implanted within the cardiovascular system and coupled to an implantable medical device, a practical estimation of a cardiovascular pressure can be obtained on a chronic basis without requiring the use other invasive sensors, such as micronanometer transducers.
摘要:
An implantable cardioverter defibrillator evaluates the hemodynamic stability of an arrhythmia to determine whether or not to defibrillate. The device obtains cardiac pressure and cardiac impedance data and evaluates a phase relationship between these parameters. Hemodynamically stable rhythms will result in an out of phase relationship.
摘要:
Techniques for estimating a cardiac chamber or vascular pressure based upon impedance are described. A device or system may measure an impedance between at least two electrodes implanted within or proximate to a cardiovascular system. The device or system may estimate a pressure of an element of the cardiovascular system based on a relationship between impedance and volume of the element, and based on a empirical relationship between the volume and the pressure. The device or system may also estimate the dimension of the element based on the impedance-volume relationship, or other characteristics based on the impedance. Because the impedance measurements may be obtained, in some examples, by using electrodes and leads implanted within the cardiovascular system and coupled to an implantable medical device, a practical estimation of a cardiovascular pressure can be obtained on a chronic basis without requiring the use other invasive sensors, such as micronanometer transducers.
摘要:
A cardiovascular analysis system and method includes an implantable medical device with a sensor positioned to sense a hemodynamic pressure over time. The implantable medical device generates hemodynamic pressure waveform data based upon the hemodynamic pressure sensed. A processor analyzes the hemodynamic waveform data to provide an indication of cardiovascular health based upon prominent peaks in the hemodynamic waveform data.
摘要:
Methods and/or devices are disclosed herein for monitoring cardiac impedance signal and delivering therapy to a patient's heart based upon the monitored cardiac impedance.
摘要:
The capability to suspend a patient alert relating to a monitored physiologic parameters addresses a need to selectively shut off a patient-alert signal or signals during the time a patient is being treated for an excursion in the parameter. Of course, in general a signal call attention to a patient's a potentially deleterious status or condition for which they should seek medical attention. Once a chronically-implanted monitoring device has detected or provided information about the parameter relative to a desired value, trend, or range and a clinician has been notified and intervened the alert signal is temporarily disabled for a predetermined period. That is, once the notification occurs and alert has served its purpose, the alert mechanism is selectively deactivated while the patient ostensibly begins to gradually correct the monitored physiologic parameter under a caregiver's direction and control. After which time, the alert will reactivate.
摘要:
The disclosure describes techniques for quantifying the autonomic nervous system (ANS) health of a patient with thoracic impedance measurements. Thoracic impedance may be measured utilizing cardiac electrodes and an implantable medical device housing or other electrodes located on or within the patient. Since greater variability in thoracic impedance may indicate better health of the ANS, monitoring impedance changes in a patient may be used to quantify autonomic tone of the ANS, and ultimately, overall patient health. In some examples, thoracic impedance may be measured in response to a change in patient posture for acute monitoring or at predetermined times over several days, weeks, or months for more chronic monitoring of the patient. An implantable medical device may independently analyze the impedance measurements and transmit an alert to the patient or clinician when impedance changes indicate a change in patient health.
摘要:
The capability to suspend a patient alert relating to a monitored physiologic parameters addresses a need to selectively shut off a patient-alert signal or signals during the time a patient is being treated for an excursion in the parameter. Of course, in general a signal call attention to a patient's a potentially deleterious status or condition for which they should seek medical attention. Once a chronically-implanted monitoring device has detected or provided information about the parameter relative to a desired value, trend, or range and a clinician has been notified and intervened the alert signal is temporarily disabled for a predetermined period. That is, once the notification occurs and alert has served its purpose, the alert mechanism is selectively deactivated while the patient ostensibly begins to gradually correct the monitored physiologic parameter under a caregiver's direction and control. After which time, the alert will reactivate.