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High-Resolution Endocardial and Epicardial Optical Mapping in a Sheep Model of Stretch-Induced Atrial Fibrillation
Published on: July 29, 2011
Intramural activation during early human ventricular fibrillation
Krishnakumar Nair1, Karthikeyan Umapathy, Talha Farid
1The Hull Family Cardiac Fibrillation Management Laboratory, University Health Network, Toronto, Ontario, Canada.
Circulation. Arrhythmia and Electrophysiology
|July 14, 2011
Summary
Early human ventricular fibrillation (VF) involves transmural scroll wave activation, not multiple reentrant wavefronts. This intramural reentry is linked to areas with increased fibrosis.
Area of Science:
- Cardiology
- Electrophysiology
- Cardiac Anatomy
Background:
- Investigated intramural activation patterns in early human ventricular fibrillation (VF).
- Hypothesized that intramural reentry colocalizes with increased intramural fibrosis.
Purpose of the Study:
- To elucidate the intramural activation patterns during early human VF.
- To determine the relationship between intramural reentry and fibrosis.
Main Methods:
- Utilized Langendorff-perfused human hearts (n=13).
- Employed plunge needles with 4 unipoles for intramural mapping (100 sites).
- Conducted global mapping during VF episodes and high-resolution optical mapping.
Main Results:
- Simultaneous activation was the most common intramural pattern (48.7%).
- Transmural scroll waves were identified, confirmed by simultaneous epicardial/endocardial mapping and optical mapping.
- Sites of intramural reentry exhibited significantly greater fibrosis (53.3%) compared to non-reentrant areas (27.5%, P=0.02).
Conclusions:
- Early human VF is best explained by transmural scroll wave activation.
- Intramural reentry during VF localizes to regions with increased intramural fibrosis.
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