摘要:
A medical device and associated method control the delivery of a cardiac pacing therapy including selecting left ventricular pacing sites for delivering the therapy. The left ventricular pacing sites are selected by delivering pacing pulses to a patient's left ventricle at multiple pacing sites one at a time and determining right ventricular activation times in response to the pacing pulses being delivered at each of the pacing sites. A left ventricular pacing site is selected in response to the determined right ventricular activation times.
摘要:
A medical device system and method for delivering mechanically fused left ventricular cardiac stimulation. A sensor monitors left ventricular acceleration while left ventricular cardiac stimulation is provided at an AV interval. The left ventricular acceleration is used to calculate a mechanical response interval and the mechanical response interval is compared to a desired mechanical response interval. The AV interval is adjusted until the mechanical response interval is equal to the desired mechanical response interval.
摘要:
Techniques are described for detecting conduction abnormalities in a heart of a patient. In particular, an IMD may be configured to obtain electrical signals corresponding to cardiac activity of the heart of the patient and periodically analyze a most recent electrical signal of the obtained electrical signals to detect an electrical conduction abnormality of the heart. The IMD adjusts a frequency at which the most recent electrical signal is analyzed based on at least one physiological parameter of the patient. For example, the IMD may increase the frequency at which the most recent electrical signal is analyzed when a heart rate parameter has significantly changed and the number of detected premature ventricular contractions (PVCs) is greater than or equal to a threshold number. In this manner, the most recent electrical signal is analyzed at a higher frequency in situations in which conduction abnormalities are more likely.
摘要:
Methods for optimizing an atrioventricular (AV) pacing delay interval based upon ECG-based optimization such that an AV pacing delay interval value can be dynamically adjusted in an ambulatory subject. Ends of P-waves are determined. An operating atrioventricular interval is modified to maintain intervals between the determined ends of P-waves and beginnings of corresponding following QRS complexes above a predetermined certain value. The value may be between 30 and 60 milliseconds.
摘要:
An implantable medical device receives both heart sound and electrogram signals. A processor within the implantable medical device extracts physiologically relevant information from both the heart sound signal and the electrogram signal. Based on the extracted physiologically relevant information a set of pacing parameters is evaluated. In certain examples, the values of the pacing parameters may be changed by the implantable medical device in response to the physiologically relevant information extracted from the heart sound signal and the electrogram signal.
摘要:
Provided herewith are methods and apparatus for optimizing an atrioventricular (AV) pacing delay interval based upon ECG-based optimization is calculated as a linear function of P-wave duration, sensed PR (intrinsic) interval, sensed or paced QRS duration and heart rate. Since the relationship among these parameters is linear, once the coefficients are solved (which can be any value, including null) with reference to a known optimized AV interval (AVopt) such as from an echocardiographic study, an AVopt value can be dynamically adjusted in an ambulatory subject. The various combinations of values can be loaded into a look up table or calculated automatically. And, since some of the parameters do not typically change much over time they can be determined acutely and fed into the equation while the other values can be measured frequently. The parameter values can be measured by an implantable medical device such as a dual- or triple-chamber pacemaker.
摘要:
The disclosure provides methods and apparatus of left ventricular pacing including automated adjustment of a atrio-ventricular (AV) pacing delay interval and intrinsic AV nodal conduction testing. It includes—upon expiration or reset of a programmable AV Evaluation Interval (AVEI)—performing the following: temporarily increasing a paced AV interval and a sensed AV interval and testing for adequate AV conduction and measuring an intrinsic atrio-ventricular (PR) interval for a right ventricular (RV) chamber. Thus, in the event that the AV conduction test reveals a physiologically acceptable intrinsic PR interval then storing the physiologically acceptable PR interval in a memory structure (e.g., a median P-R from one or more cardiac cycles). In the event that the AV conduction test reveals an AV conduction block condition or if unacceptably long PR intervals are revealed then a pacing mode-switch to a bi-ventricular (Bi-V) pacing mode occurs and the magnitude of the AVEI is increased.
摘要:
Novel methods and apparatus for dynamically monitoring paced and sensed P-wave duration, P-wave end and/or QRS duration and/or S-T segment duration, or length, in a patient having an implantable medical device (IMD) provides diagnostic and clinical benefit allowing for predictions about future arrhythmia, advanced notification, alert and intervention as well as providing acute and chronic information regarding cardiac status, including both possibly declining and/or improving cardiac function. The methods can be performed using a wide variety of IMDs, such as pacemakers, cardiac resynchronization therapy (CRT) device, implantable cardioverter defibrillators (ICDs), and implantable loop recorders (e.g., such as the REVEALS device manufactured by Medtronic, Inc.).
摘要:
A medical device system and method for delivering mechanically fused left ventricular cardiac stimulation. A sensor monitors left ventricular acceleration while left ventricular cardiac stimulation is provided at an AV interval. The left ventricular acceleration is used to calculate a mechanical response interval and the mechanical response interval is compared to a desired mechanical response interval. The AV interval is adjusted until the mechanical response interval is equal to the desired mechanical response interval.
摘要:
A medical device system and method for delivering mechanically fused left ventricular cardiac stimulation. A sensor monitors left ventricular acceleration while left ventricular cardiac stimulation is provided at an AV interval. The left ventricular acceleration is used to calculate a mechanical response interval and the mechanical response interval is compared to a desired mechanical response interval. The AV interval is adjusted until the mechanical response interval is equal to the desired mechanical response interval.