Conditional Biventricular Pacing for AV Synchrony
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current implantable medical devices for cardiac pacing, particularly those using dual chamber pacing, often result in increased risks of atrial fibrillation and heart failure due to obligatory right ventricular apex pacing, which disrupts atrioventricular timing and ventricular contraction synchrony, failing to effectively address cardiac conditions in patients with systolic heart failure and normal ventricular conduction.
Innovation Solution
The development of a minimal biventricular pacing mode (MBVP) and conditional triple chamber pacing (CTCP) protocols that prioritize intrinsic conduction by allowing prolonged atrial-ventricular intervals, minimizing unnecessary ventricular pacing, and providing backup biventricular pacing when necessary, using a microprocessor-based implantable pulse generator to monitor and adjust pacing based on real-time atrioventricular interval behavior.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional dual chamber pacing is used to control heart rate and maintain AV synchrony, then heart rate control and AV synchrony are improved, but the risks of atrial fibrillation and heart failure increase due to obligatory right ventricular apex pacing
Solution Approach 1:
The pacemaker dynamically switches between different pacing modes (atrial-based pacing and biventricular pacing) based on real-time detection of AV conduction status. The system adapts its operation by monitoring whether AV conduction is present and adjusting the pacing strategy accordingly, rather than using a fixed obligatory RV apex pacing approach.
Solution Approach 2:
The invention changes the pacing parameters by transitioning from obligatory RV apex pacing to conditional biventricular pacing. The system modifies the pacing mode, timing intervals, and ventricular stimulation strategy based on detected AV conduction characteristics, thereby optimizing hemodynamic outcomes and reducing adverse effects.
2Reliability
If obligatory right ventricular apex pacing is used to ensure AV synchrony, then AV synchrony is maintained, but ventricular contraction synchrony is disrupted
Solution Approach 1:
The system dynamically adjusts ventricular pacing strategy based on detected AV conduction. When AV conduction is present, the system allows natural ventricular activation sequences. When AV conduction is absent or impaired, the system activates biventricular pacing to restore synchronized contraction, thereby maintaining both AV synchrony and ventricular contraction synchrony under different physiological conditions.
Solution Approach 2:
The invention creates a backup biventricular pacing mode that copies and replaces the natural conduction system when it fails. By providing an alternative electrical activation pathway through biventricular pacing, the system ensures that ventricular contraction synchrony is maintained even when intrinsic conduction is inadequate.
3Productivity
If intrinsic conduction is allowed to proceed with prolonged atrial-ventricular intervals to minimize ventricular pacing, then ventricular pacing is minimized, but atrial-ventricular timing may become abnormal
Solution Approach 1:
The system continuously monitors AV interval duration and ventricular conduction status, using this feedback to determine when to switch between atrial-based pacing and biventricular pacing modes. The feedback mechanism ensures that prolonged AV intervals do not result in abnormal timing by detecting conduction abnormalities and triggering appropriate pacing intervention.
Solution Approach 2:
The pacemaker acts as an intermediary that mediates between atrial activation and ventricular response. By inserting pacing pulses at appropriate moments based on monitored AV intervals, the system ensures proper timing relationships are maintained while still allowing natural conduction to proceed when appropriate.
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
An implantable pacing system with single, double and triple chamber pacing capabilities, provided individually or in concert on a conditional or continuous basis depending upon ongoing analyses of atrial rhythm status, atrioventricular conduction status and ventricular rate. A mode is selected to reduce the occurrence of any ventricular pacing in favor of intrinsic atrioventricular and ventricular conduction. If excessively long PR intervals are occurring too frequently or atrioventricular conduction is unreliable or absent, the implantable pulse generator is operated in a conditional triple chamber pacing mode that provides atrial-synchronous biventricular pacing in every cardiac cycle for a period of time as necessary to restore and maintain AV synchrony, while minimizing ventricular asynchrony otherwise associated with monochamber RV pacing as in conventional dual chamber pacing systems. Similarly, biventricular pacing is provided in every cardiac cycle when ventricular rates are undesirably slow during atrial fibrillation, where AV synchronization is excluded.