Ventricular Pacing Delay Optimization During Atrial Fibrillation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

During episodes of atrial fibrillation, existing cardiac pacing systems face challenges in reliably determining optimal interventricular pacing delays due to irregular atrio-ventricular conduction, making it difficult to distinguish between interventricular and atrial conduction events, which affects the accuracy of ventricular pacing.

Innovation Solution

The method involves determining the degree of variation in antecedent and succedent intervals between ventricular events on different channels to establish the true order of QRS complexes and calculate intrinsic interventricular conduction delays, allowing for accurate setting of ventricular pacing intervals through RV and LV pace tests, even during non-atrial tracking modes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional V sense tests are performed during atrial fibrillation, then ventricular pacing delays can be determined, but the irregular AV conduction makes it difficult to reliably determine the order of LV and RV QRS complexes and hence cannot reliably determine the value of intrinsic interventricular conduction delay

Engineering Contradiction:

Improvedetermination of intrinsic interventricular conduction delayVSAvoidreliability of V sense test during AF

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent implements dynamic adaptation by switching between different pacing modes (atrial tracking vs. non-atrial tracking) based on detected arrhythmia conditions. During AF, the system dynamically adjusts the testing approach by using non-atrial tracking modes and modifying how conduction delays are calculated, allowing continuous optimization despite changing cardiac conditions.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes key parameters including pacing mode selection (from atrial tracking to non-atrial tracking), timing interval measurements (using alternative interval calculations during AF), and testing protocols (modifying V sense test execution). These parameter changes enable reliable measurement of interventricular conduction delays even when AV conduction becomes irregular during atrial fibrillation.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If the device switches to non-atrial tracking mode during AF, then ventricular pacing can continue, but it becomes difficult to reliably perform LV pace and RV pace tests to determine paced interventricular conduction delays

Engineering Contradiction:

Improvecontinuation of ventricular pacing during AFVSAvoiddetermination of paced interventricular conduction delay

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The system performs preliminary detection of AF conditions and proactively switches to non-atrial tracking mode before attempting pace tests. By preparing the system in advance and selecting appropriate pacing modes beforehand, the device ensures that when pace tests are performed during AF, they are conducted under optimal conditions that account for the irregular conduction patterns.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses the pacing mode selection as an intermediary mechanism that mediates between the conflicting requirements of maintaining ventricular pacing continuity and ensuring accurate measurement of conduction delays. By introducing this intermediate control layer, the system can adaptively choose the most appropriate testing approach based on real-time cardiac conditions.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Adaptability or versatility

If AV conduction is irregular during AF, then the chaotic atrial beating occurs, but this makes it difficult to distinguish between interventricular and atrial conduction events

Engineering Contradiction:

Improvehandling of irregular AV conduction during AFVSAvoiddistinguishing conduction events

Core Design Contradiction:

Adaptability or versatilityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent segments the conduction analysis by separately evaluating atrial and ventricular events through distinct sensing channels and timing measurements. By dividing the complex conduction pathway into separable measurement components (atrial activation, AV conduction, ventricular activation), the system can independently analyze each segment even when overall conduction becomes irregular during AF, enabling reliable distinction between different conduction events.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS8346359B2Systems and methods for optimizing ventricular pacing delays during atrial fibrillation

Publication Date: 2013.01.01 PACESETTER INC

AI summary

Techniques are provided for use by implantable medical devices for controlling ventricular pacing, particularly during atrial fibrillation. In one example, during a V sense test for use in optimizing ventricular pacing, the implantable device determines relative degrees of variation within antecedent and succedent intervals detected between ventricular events sensed on left ventricular (LV) and right ventricular (RV) sensing channels. Preferred or optimal ventricular pacing delays are then determined, in part, based on a comparison of the relative degrees of variation obtained during the V sense test. In another example, during RV and LV pace tests, the device distinguishes QRS complexes arising due to interventricular conduction from QRS complexes arising due to atrioventricular conduction from the atria, so as to permit the determination of correct paced interventricular conduction delays for the patient. The paced interventricular conduction delays are also used to optimize ventricular pacing. Biventricular and monoventricular pacing regimes are provided.