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Estimating Bilateral Atrial Function by Cardiovascular Magnetic Resonance Feature Tracking in Patients with Paroxysmal Atrial Fibrillation
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Left Atrial Enhancement Correlates With Myocardial Conduction Velocity in Patients With Persistent Atrial
Rheeda L Ali1,2,3, Norman A Qureshi1,2, Silvia Liverani4
1ElectroCardioMaths Programme of The Imperial Centre for Cardiac Engineering, Imperial College London, London, United Kingdom.
Frontiers in Physiology
|December 11, 2020
Summary
Left atrial fibrosis, measured by LGE-CMRI, correlates with conduction velocity (CV) at clinically relevant scales. Normalized intensity (NI) provides reproducible mapping of myocardial conduction properties for risk stratification.
Area of Science:
- Cardiology
- Biomedical Engineering
- Medical Imaging
Background:
- Conduction velocity (CV) heterogeneity and myocardial fibrosis are implicated in re-entry arrhythmias.
- The precise relationship between left atrial (LA) fibrosis, assessed by LGE-CMRI, and CV remains unclear.
Purpose of the Study:
- To investigate the localized relationship between LA fibrosis (LGE-CMRI) and CV.
- To assess LGE-CMRI as a tool for mapping myocardial conduction properties for risk stratification and treatment guidance in persistent atrial fibrillation (AF).
Main Methods:
- Acquired 3D LA electroanatomic maps during LA pacing in eight patients with persistent AF.
- Computed local CVs using electrograms and co-registered them with LGE-CMRI data.
- Quantified fibrosis using normalized intensity (NI) and image intensity ratio (IIR), evaluating associations with multilevel linear regression.
Main Results:
- Observed a significant association between CV and LGE-CMRI intensity at scales similar to mapping electrodes (-0.11 m/s per NI unit, -0.96 m/s per IIR unit).
- The association's magnitude decreased with larger measurement areas.
- Normalized intensity (NI) demonstrated reproducible associations, unlike the image intensity ratio (IIR).
Conclusions:
- LGE-CMRI intensity correlates with CV at clinically relevant spatial scales comparable to mapping catheter electrodes.
- Measurement scale is critical for accurately quantifying the CV-LGE-CMRI association.
- Normalized intensity (NI) is superior to IIR for quantitative, reproducible mapping due to its ability to account for CMRI dynamic range changes.
Keywords:
Atrial fibrillationLGE-MRIconduction velocitieselectro anatomical mappingfibrosisimage segmentationleft atriumMore Related Videos
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