Multi-site LV Pacing Capture Verification
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current automatic capture verification and threshold search algorithms for multi-site left ventricular pacing in cardiac stimulation devices are ineffective when multiple pacing pulses are delivered within the same cardiac cycle, leading to energy wastage and challenges in detecting capture and loss of capture, especially in cases of ventricular fusion.
Innovation Solution
The implementation of a system that uses multiple electrodes to deliver pacing pulses at two or more sites within the left ventricular chamber with programmed delays, monitoring evoked responses, and adjusting pacing parameters or delivering backup pulses to ensure global capture and minimize energy usage, while also promoting beneficial ventricular fusion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple pacing pulses are delivered within the same cardiac cycle for multi-site left ventricular pacing, then the effectiveness of ventricular resynchronization is improved, but the reliability of capture detection deteriorates due to ventricular fusion
Solution Approach 1:
The patent segments the capture detection process into separate analysis for each pacing site. The system monitors evoked responses at multiple LV sites independently, allowing capture verification at each site even when ventricular fusion occurs. This segmentation enables reliable detection by analyzing local responses rather than relying on a single global response that may be obscured by fusion.
Solution Approach 2:
The patent introduces an intermediary approach by using the evoked response from one LV site as a reference to detect capture at another site. When ventricular fusion occurs, the system can still detect capture by comparing the expected evoked response morphology with the actual sensed signal, using the known pacing sequence and electrode configuration as intermediaries to disambiguate the fused signals.
2Device complexity
If traditional capture verification algorithms are used for multi-site pacing, then device complexity is minimized, but energy wastage increases due to inability to detect loss of capture
Solution Approach 1:
The patent applies preliminary action by delivering a backup pacing pulse at a predetermined time interval after the primary pacing pulse, before loss of capture would become clinically significant. This backup pulse is delivered proactively based on the timing of the primary pulse and known conduction intervals, ensuring continuous capture without requiring complex real-time detection algorithms.
Solution Approach 2:
The system implements feedback by monitoring evoked responses following each pacing pulse and using this information to control delivery of subsequent pacing pulses. When an evoked response is detected indicating successful capture, the system adjusts pacing parameters or reduces backup pulse delivery, thereby reducing energy consumption while maintaining reliable capture.
3Reliability
If pacing parameters are adjusted to achieve reliable capture, then capture reliability is improved, but energy consumption increases
Solution Approach 1:
The patent dynamically changes pacing parameters including pulse amplitude, pulse width, and timing intervals based on detected evoked responses. When capture is confirmed through evoked response monitoring, the system can reduce pulse amplitude or width to minimize energy consumption while maintaining capture. Conversely, when loss of capture is detected, parameters are increased to restore reliable capture, optimizing the balance between reliability and energy use.
Solution Approach 2:
The system uses partial action by delivering backup pacing pulses only when necessary, rather than continuously. By monitoring evoked responses and detecting loss of capture only when it occurs, the system delivers backup pulses selectively rather than excessively, reducing overall energy consumption while maintaining adequate capture reliability through targeted intervention.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively adjusts pacing parameters to achieve reliable capture without excessive energy consumption, ensuring consistent global capture and reducing undesired ventricular fusion, thereby improving the efficiency and effectiveness of multi-site left ventricular pacing.
Implementation Method 1
pacemakers can deliver pacing pulses to a heart chamber to induce a depolarization of that chamber and this is followed by a mechanical contraction of that chamber
Implementation Method 2
sensing circuits that sense cardiac activity for the detection of intrinsic cardiac events such as intrinsic atrial depolarizations (detectable as P waves) and intrinsic ventricular depolarizations (detectable as R waves)
Data Source
AI summary
Various embodiments of the present invention are directed to, or are for use with, an implantable system including a lead having multiple electrodes implantable in a patient's left ventricular (LV) chamber. In accordance with an embodiment, the patient's LV chamber is paced at first and second sites within the LV chamber using a programmed LV1-LV2 delay, wherein the LV1-LV2 delay is a programmed delay between when first and second pacing pulses are to be delivered respectively at the first and second sites within the LV chamber. Evoked responses to the first and second pacing pulses are monitored for, and one or more LV pacing parameter is/are adjusted and/or one or more backup pulse is/are delivered based on results of the monitoring.