Leadless Pacemaker CRT Timing via Reduction Factor
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The absence of an intracardiac lead in leadless cardiac pacemakers (LCPs) makes it difficult to detect atrial events for cardiac resynchronization therapy (CRT), as they lack independent atrial timing references, which is essential for effective CRT delivery.
Innovation Solution
The method involves determining a PR interval and a reduction factor to adjust the timing of pacing therapies, allowing the LCP to deliver synchronization paces at intervals relative to native beat intervals, even without an atrial lead, using external programmers or other implantable devices for data communication and calculation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If transvenous leads are used to deliver CRT, then atrial event detection is enabled, but lead failure and morbidity increase
Solution Approach 1:
The patent extracts the leadless pacemaker from the traditional transvenous lead system, implanting the device directly in the heart chamber without requiring intracardiac leads. This eliminates lead-related failures and morbidities while maintaining CRT functionality through alternative sensing methods using the device housing as an electrode.
Solution Approach 2:
The leadless pacemaker device performs multiple functions: it provides pacing therapy, serves as a sensing electrode for atrial events, and acts as a return electrode for CRT delivery. This multi-functionality eliminates the need for separate leads while maintaining therapeutic effectiveness.
2Reliability
If leadless cardiac pacemaker is used, then lead-related complications are eliminated, but atrial event detection capability is lost
Solution Approach 1:
The device housing serves as an intermediary element, functioning as both the pacemaker housing and the sensing electrode for detecting atrial events. This eliminates the need for separate atrial leads while maintaining sensing capability through the housing's electrical contact with cardiac tissue.
Solution Approach 2:
The leadless pacemaker device performs multiple functions: it provides pacing therapy, serves as a sensing electrode for atrial events, and acts as a return electrode for CRT delivery. This multi-functionality eliminates the need for separate leads while maintaining sensing capability.
3Device complexity
If reduction factor method is used for timing, then atrial lead is eliminated, but timing precision for CRT is reduced
Solution Approach 1:
The patent replaces the mechanical/electrical connection of atrial leads with a computational approach using reduction factors. The device calculates appropriate pacing intervals by applying predetermined reduction factors to sensed R-R intervals, substituting direct electrical atrial sensing with algorithm-based timing derivation.
Solution Approach 2:
The system changes the timing parameter from direct atrial-to-ventricular interval measurement to a derived interval based on R-R interval and reduction factor. This parameter transformation allows timing estimation without requiring direct atrial electrical sensing, accommodating the leadless device architecture.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Methods, systems and devices for providing cardiac resynchronization therapy (CRT) to a patient using a leadless cardiac pacemaker (LCP) implanted in or proximate the left ventricle of a patient. A setup phase is used to establish parameters in the therapy delivery. In operation, the method and/or device will sense at least one non-paced cardiac cycle to determine a native R-R interval, and then delivers a synchronization pace at an interval less than the native R-R interval followed by a plurality of pace therapies delivered at the R-R interval or a modification thereof.